WTNT41 KNHC 292058
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM AST FRI OCT 29 2010
 
AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INVESTIGATING THE
VIGOROUS TROPICAL WAVE LOCATED SOUTHEAST OF THE WINDWARD ISLANDS
FOUND A CLOSED SURFACE CIRCULATION...ALONG WITH FLIGHT-LEVEL WINDS
AND UNCONTAMINATED SFMR SURFACE WINDS THAT SUPPORT A 35-KT TROPICAL
STORM. AS A RESULT...ADVISORIES HAVE BEEN INITIATED ON TROPICAL
STORM TOMAS...THE NINETEENTH NAMED STORM OF THE 2010 SEASON.

THE INITIAL MOTION IS AN UNCERTAIN 295/15...DUE TO THE POSSIBILITY
OF REFORMATION OF THE LOW-LEVEL CENTER WITHIN THE CENTRAL DEEP
CONVECTION. TOMAS IS EXPECTED TO CONTINUE MOVING WEST-NORTHWESTWARD
FOR THE NEXT 48 HOURS...PASSING THROUGH THE WINDWARD ISLANDS IN
ABOUT 24 HOURS OR SO. AFTER THAT...THE BROAD TROUGH THAT IS LOCATED
OFF THE U.S. EAST COAST AND THE BAHAMAS IS FORECAST TO LIFT OUT TO
THE NORTHEAST...WHICH ALLOWS A RIDGE TO BUILD TO THE NORTH OF TOMAS
ACROSS THE GREATER ANTILLES...THE BAHAMAS...AND FLORIDA. THE
EASTERLY FLOW ON THE SOUTH SIDE OF THE RIDGE SHOULD FORCE TOMAS ON
MORE OF A WESTERLY TRACK THROUGH 96 HOURS. BY DAY 5...A SECOND MUCH
DEEPER TROUGH IS EXPECTED TO DIG SOUTHWARD INTO THE SOUTHERN PLAINS
AND SOUTHEASTERN U.S. AND CAUSE THE RIDGE AND ASSOCIATED STEERING
CURRENTS TO WEAKEN. THE RESULT SHOULD BE A SHARP DECREASE IN
FORWARD SPEED BY 120 HOURS. THE NHC MODEL GUIDANCE IS IN GOOD
AGREEMENT ON THIS DEVELOPING SCENARIO...EXCEPT FOR THE GFDL AND
HWRF MODELS...WHICH ARE CONSIDERED TO BE OUTLIERS AT THIS TIME. 
THE OFFICIAL FORECAST TRACK IS ALONG THE SOUTHERN EDGE OF THE
GUIDANCE ENVELOPE...BUT NOT AS FAR SOUTH AND WEST AS THE GFS...
ECMWF...AND UKMET MODELS...WHICH ARE DEPICTING A MUCH WEAKER AND
SMALLER TROPICAL CYCLONE THAN IS EXPECTED.
 
RECON AND SATELLITE DATA INDICATE THE LOW-LEVEL AND UPPER-LEVEL
CIRCULATIONS ARE NOT YET VERTICALLY ALIGNED...WHICH SHOULD RESULT
IN ONLY SLOW INTENSIFICATION IN THE NEAR TERM. HOWEVER...WITH A
CENTRAL PRESSURE OF 998 MB...VERY MOIST MID-LEVELS...AND LOW
VERTICAL SHEAR...IT WOULD NOT TAKE MUCH FOR TOMAS TO INTENSIFY AT A
FASTER THAN NORMAL RATE. WHILE NOT EXPLICITLY INDICATING RAPID
INTENSIFICATION...THE OFFICIAL INTENSITY FORECAST REFLECTS THESE
FAVORABLE ENVIRONMENTAL CONDITIONS...AND IS ABOVE THE SHIPS/LGEM
INTENSITY MODEL GUIDANCE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/2100Z 11.1N  57.5W    35 KT
 12HR VT     30/0600Z 12.0N  59.5W    40 KT
 24HR VT     30/1800Z 12.9N  61.8W    50 KT
 36HR VT     31/0600Z 13.5N  64.0W    60 KT
 48HR VT     31/1800Z 14.1N  66.2W    70 KT
 72HR VT     01/1800Z 14.8N  70.4W    90 KT
 96HR VT     02/1800Z 15.2N  74.0W   100 KT
120HR VT     03/1800Z 16.0N  76.0W   100 KT
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 300003
TCDAT1
TROPICAL STORM TOMAS SPECIAL DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
800 PM AST FRI OCT 29 2010
 
ON THE LAST PASS THROUGH THE CENTER OF TOMAS...THE AIR FORCE
RECONNAISSANCE AIRCRAFT REPORTED A MAXIMUM FLIGHT-LEVEL WIND OF 61
KT AND SFMR MEASUREMENTS AROUND 50 KT.  THE WINDS HAVE INCREASED
FASTER THAN WAS INDICATED IN THE PREVIOUS ADVISORY...AND A SPECIAL
ADVISORY IS BEING ISSUED TO INCREASE THE INTENSITY FORECAST THROUGH
THE FIRST 48 HOURS.  IN ADDITION...THE WIND RADII WERE EXPANDED IN
ACCORDANCE WITH THE RECONNAISSANCE DATA.

BUOY 41101 IS ALREADY REPORTING SEAS OF 13 FT WELL NORTH OF THE
CENTER...REQUIRING AN EXPANSION OF THE 12-FT SEAS RADII.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0000Z 11.6N  57.6W    50 KT
 12HR VT     30/0600Z 12.0N  59.5W    55 KT
 24HR VT     30/1800Z 12.9N  61.8W    60 KT
 36HR VT     31/0600Z 13.5N  64.0W    70 KT
 48HR VT     31/1800Z 14.1N  66.2W    80 KT
 72HR VT     01/1800Z 14.8N  70.4W    90 KT
 96HR VT     02/1800Z 15.2N  74.0W   100 KT
120HR VT     03/1800Z 16.0N  76.0W   100 KT
 
$$
FORECASTER BERG/BROWN
 

WTNT41 KNHC 300245
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM AST FRI OCT 29 2010
 
AS MENTIONED IN THE 0000 UTC SPECIAL ADVISORY...THE AIR FORCE
RECONNAISSANCE AIRCRAFT REPORTED A MAXIMUM FLIGHT-LEVEL WIND OF 61
KT AND SFMR MEASUREMENTS BETWEEN 50-55 KT...ALBEIT IN SOME HEAVY
RAIN...ON THE LAST PASS THROUGH THE CENTER.  DEEP CONVECTION HAS
CONTINUED TO INCREASE SINCE THAT TIME WITH A PROMINENT BAND FORMING
OVER THE WESTERN SEMICIRCLE...SO THE INITIAL INTENSITY IS BEING
RAISED TO 55 KT ON THIS ADVISORY.
 
TOMAS IS BENEFITING FROM EXCELLENT UPPER-LEVEL OUTFLOW IN ALMOST ALL
QUADRANTS...AND THE CYCLONE APPEARS AS THOUGH IT IS GOING THROUGH A
PERIOD OF RAPID INTENSIFICATION.  SHIPS RI GUIDANCE IS INDICATING
AT LEAST A 40 PERCENT CHANCE OF A 30-KT INCREASE IN INTENSITY OVER
THE NEXT 24 HOURS...AND IT IS LIKELY THAT TOMAS WILL REACH
HURRICANE STRENGTH WITHIN THE NEXT 12-24 HOURS.  AFTER 24
HOURS...NEARLY ALL THE INTENSITY GUIDANCE SHOWS THE INTENSITY
LEVELING OFF OR ONLY INCREASING MORE MODESTLY THROUGH 120 HOURS.
HOWEVER...GLOBAL MODEL FIELDS SHOW THE ENVIRONMENT OVER THE
CARIBBEAN BECOMING FAVORABLE FOR CONTINUED INTENSIFICATION...AND IT
IS NOT OBVIOUS AT THIS POINT WHAT MIGHT LIMIT THAT TREND.  THE
OFFICIAL FORECAST CONTINUES TO SHOW STEADY STRENGTHENING TO
CATEGORY 3 STRENGTH BY DAY 4 AND REMAINS ABOVE ALL THE RELIABLE
INTENSITY MODELS.
 
THE CENTER APPEARED TO HAVE REFORMED TO THE NORTH EARLIER THIS
EVENING...AND THE INITIAL MOTION IS ESTIMATED AT 300/14.  THE NEW
OFFICIAL TRACK FORECAST REMAINS LARGELY UNCHANGED FROM THE
PREVIOUS FORECAST...ALTHOUGH THE FIRST 12-24 HOURS OF THE TRACK
FORECAST HAVE BEEN SHIFTED A LITTLE TO THE NORTH AS AN ARTIFACT OF
THE REFORMATION OF THE CENTER.  THE GFS...ECMWF...AND GFDL ALL
SUPPORT A RELATIVELY STRONG MID-LEVEL RIDGE NORTH OF THE GREATER
ANTILLES AND SHOW TOMAS MOVING GENERALLY WESTWARD ACROSS THE
SOUTH-CENTRAL CARIBBEAN SEA.  THESE ARE USUALLY THE MOST
TRUSTWORTHY OF THE DYNAMICAL MODELS...AND THE OFFICIAL FORECAST
FAVORS THEIR SCENARIO...LYING JUST TO THE SOUTH OF THE MODEL
CONSENSUS.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0300Z 12.2N  58.4W    55 KT
 12HR VT     30/1200Z 13.0N  60.2W    65 KT
 24HR VT     31/0000Z 13.7N  62.7W    75 KT
 36HR VT     31/1200Z 14.2N  65.0W    85 KT
 48HR VT     01/0000Z 14.5N  67.1W    90 KT
 72HR VT     02/0000Z 15.0N  71.0W    95 KT
 96HR VT     03/0000Z 15.5N  74.0W   100 KT
120HR VT     04/0000Z 16.0N  76.0W   100 KT
 
$$
FORECASTER BERG/BROWN
 

WTNT41 KNHC 300849
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM AST SAT OCT 30 2010
 
THE SATELLITE PRESENTATION OF TOMAS HAS IMPROVED OVERNIGHT. AN
EARLIER GAP IN THE DEEP CONVECTION NEAR THE CENTER HAS FILLED IN
...AND THE OUTFLOW REMAINS EXCELLENT. ALSO...IMAGERY FROM THE RADAR
ON MARTINIQUE AND A 0624 UTC TRMM PASS SUGGEST THAT AN EYEWALL
MAY BE FORMING. BASED ON THESE TRENDS...THE INITIAL INTENSITY IS
RAISED TO 60 KT. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE TOMAS LATER THIS MORNING TO GET BETTER
INFORMATION ON THE STRUCTURE AND INTENSITY OF THE CYCLONE. DURING
THE NEXT DAY OR SO...CONDITIONS APPEAR FAVORABLE FOR CONTINUED
INTENSIFICATION. IN FACT...THE SHIPS MODEL RAPID INTENSITY INDEX
SHOWS A NEARLY 60 PERCENT CHANCE OF A 25-KT INCREASE IN 24 HOURS.
BEYOND THAT TIME...THE SHIPS MODEL...BASED ON GFS MODEL FIELDS...
SHOWS AN INCREASE IN SOUTHWESTERLY SHEAR...WHICH SHOULD SLOW THE
RATE OF INTENSIFICATION SOMEWHAT. AFTER 72 HOURS...THE SHEAR MAY
RELAX AND ALLOW FOR FURTHER INTENSIFICATION. THE NEW OFFICIAL
FORECAST REFLECTS THIS THINKING AND IS ABOVE ALL OF THE RELIABLE
INTENSITY MODELS THROUGH THE PERIOD.
 
THE CENTER APPEARS TO BE LOCATED A LITTLE NORTH OF THE PREVIOUS
FORECAST TRACK BASED ON THE RECENT TRMM PASS...AND THE INITIAL
MOTION ESTIMATE IS 300/13. TOMAS IS CURRENTLY BEING STEERED
WEST-NORTHWESTWARD TO THE SOUTH OF A MID-LEVEL RIDGE THAT EXTENDS
FROM THE CENTRAL ATLANTIC INTO THE NORTHEASTERN CARIBBEAN. AS A
MID-LEVEL TROUGH CURRENTLY SITUATED OVER THE SOUTHWESTERN ATLANTIC 
LIFTS OUT...ANOTHER RIDGE WILL BUILD IN NORTH OF TOMAS...WHICH
SHOULD IMPART A WEST-NORTHWESTWARD OR WESTWARD MOTION THROUGH 72
HOURS. BEYOND THAT TIME...THE GLOBAL MODELS SHOW A LONGWAVE TROUGH
MOVING INTO EASTERN NORTH AMERICA AND A CUTOFF LOW DEVELOPING IN
THE GULF OF MEXICO. THIS SHOULD WEAKEN THE RIDGE AND CAUSE A
DECREASE IN FORWARD SPEED LATE IN THE PERIOD...AND POTENTIALLY A
NORTHWARD TURN. THE TRACK MODEL ENVELOPE HAS SHIFTED NORTHWARD WITH
THIS CYCLE...BUT THE FORECAST IS ADJUSTED ONLY SLIGHTLY NORTHWARD
OUT OF RESPECT FOR THE GFS...UKMET...AND ECMWF MODELS WHICH REMAIN
FARTHER SOUTH. LATE IN THE PERIOD...THE FORWARD SPEED IS QUITE SLOW
DUE TO THE LARGE UNCERTAINTY IN THE TIMING AND SHARPNESS OF THE
POTENTIAL NORTHWARD TURN.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0900Z 12.9N  59.5W    60 KT
 12HR VT     30/1800Z 13.5N  61.3W    70 KT
 24HR VT     31/0600Z 14.1N  63.7W    80 KT
 36HR VT     31/1800Z 14.6N  65.9W    85 KT
 48HR VT     01/0600Z 15.1N  68.1W    90 KT
 72HR VT     02/0600Z 15.5N  71.5W    90 KT
 96HR VT     03/0600Z 16.0N  73.5W   100 KT
120HR VT     04/0600Z 16.5N  74.5W   100 KT
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 301501
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM AST SAT OCT 30 2010
 
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS
THIS MORNING FOUND MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 68 KT IN
THE SOUTHEAST QUADRANT ALONG WITH SEVERAL 64-66 KT RELIABLE SFMR
WINDS. IN ADDITION...A DROPSONDE IN THE NORTHEAST EYEWALL INDICATED
A SURFACE WIND OF 72 KT. HOWEVER...THE BOUNDARY-LAYER WIND PROFILES
SUGGEST A SLIGHTLY LESSER SURFACE WIND SPEED ESTIMATE OF AROUND 66
KT. A COMBINATION OF THIS DATA EASILY SUPPORTS A 65-KT HURRICANE...
AND TOMAS HAS BEEN UPGRADED ACCORDINGLY.

THE INITIAL MOTION ESTIMATE IS 290/13. THE LATEST RECON FIX
POSITIONS HAVE COME IN RIGHT ON THE PREVIOUS ADVISORY TRACK. 
UPPER-AIR DATA FROM SAN JUAN REVEALED 30-METER 500 MB HEIGHT
INCREASES DURING THE PAST 24 HOURS...WHICH CLEARLY INDICATES THAT
MID-LEVEL RIDGING TO THE NORTH OF TOMAS HAS STARTED AS THE
DEEP-LAYER TROUGH THAT HAS CAPTURED HURRICANE SHARY LIFTS RAPIDLY
TO THE NORTHEAST AWAY FROM THE CARIBBEAN REGION. LOW- TO MID-LEVEL
RIDGING IS FORECAST BY ALL OF THE GLOBAL MODELS TO CONTINUE
BUILDING WESTWARD ACROSS THE LESSER AND GREATER ANTILLES FOR THE
NEXT 72-96 HOURS. THIS SHOULD GRADUALLY FORCE TOMAS ON A MORE
WESTERLY TRACK...ESPECIALLY AFTER 48 HOURS. HOWEVER...BY DAY 5...A
BROAD MID-TROPOSPHERIC TROUGH CURRENTLY LOCATED ALONG THE U.S. WEST
COAST IS FORECAST TO MOVE EASTWARD INTO THE CENTRAL U.S. BY DAYS
2-3 AND THEN DIG MORE SOUTHEASTWARD AFTER THAT...AND INTO THE GULF
OF MEXICO AND SOUTHEASTERN MEXICO BY DAY 5. THIS IS EXPECTED TO
RESULT IN A SIGNIFICANT EROSION OF THE WESTERN PORTION OF THE RIDGE
AND A WEAKENING OF THE STEERING CURRENT ACROSS THE WESTERN AND
CENTRAL CARIBBEAN SEA. THIS WEAK FLOW REGIME SHOULD ALLOW TOMAS TO
SLOW DOWN AND GRADUALLY MOVE NORTHWARD. THE OFFICIAL FORECAST TRACK
IS JUST AN UPDATE AND EXTENSION OF THE PREVIOUS ADVISORY TRACK...
AND REMAINS ALONG THE SOUTHERN EDGE OF THE NHC GUIDANCE ENVELOPE.

TOMAS HAS DEVELOPED A 30-40 NMI DIAMETER EYE NOTED IN RECENT RADAR
IMAGES FROM MARTINIQUE. THE UPPER-LEVEL OUTFLOW PATTERN IS WELL
ESTABLISHED AND CONTINUES TO IMPROVE. A COMBINATION OF THE
AFOREMENTIONED FEATURES ALONG WITH DEEP WARM WATER AHEAD OF THE
CYCLONE SHOULD RESULT IN CONTINUED STRENGTHENING FOR THE NEXT 24
HOURS OR SO. AFTER THAT...HOWEVER...WESTERLY 300 MB WINDS ARE
EXPECTED TO UNDERCUT THE IMPRESSIVE OUTFLOW LAYER AND INDUCE SOME
SHEAR ON TOMAS...WHICH MAY HALT THE INTENSIFICATION PROCESS. 
USUALLY WITH WESTERLY SHEAR COMES DRY AIR MID-LEVEL AIR...AND THIS
INHIBITING FACTOR WAS CLEARLY INDICATED IN UPPER-AIR DATA WEST OF
65W LONGITUDE THIS MORNING. BY 72 HOURS...ENVIRONMENTAL CONDITIONS
ARE EXPECTED TO IMPROVE AS TOMAS SLOWS DOWN...AND A INTENSIFICATION
IS EXPECTED TO RESUME. THE OFFICIAL INTENSITY FORECAST IS ABOVE THE
SHIPS/LGEM MODELS...AND IS SIMILAR TO THE PREVIOUS FORECAST AND
LAST TWO GFDL MODEL RUNS...WHICH MAKES A TOMAS A MAJOR HURRICANE
SOUTH OF HISPANIOLA.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/1500Z 13.3N  60.7W    65 KT
 12HR VT     31/0000Z 13.8N  62.5W    75 KT
 24HR VT     31/1200Z 14.4N  64.8W    80 KT
 36HR VT     01/0000Z 14.8N  67.2W    80 KT
 48HR VT     01/1200Z 15.2N  69.2W    85 KT
 72HR VT     02/1200Z 15.6N  72.3W    90 KT
 96HR VT     03/1200Z 16.0N  74.0W   100 KT
120HR VT     04/1200Z 16.5N  75.0W   100 KT
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 302046
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM AST SAT OCT 30 2010
 
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS
THIS AFTERNOON FOUND MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 67 KT IN
THE NORTH QUADRANT...WHICH EQUATES TO ABOUT 60 KT SURFACE WINDS.
SATELLITE INTENSITY ESTIMATES ARE A CONSENSUS T4.0/65 KT FROM TAFB
AND SAB. THE STRUCTURE OF TOMAS HAS IMPROVED CONSIDERABLY IN RADAR
IMAGERY FROM MARTINIQUE...AND THE CYCLONE NOW POSSESSES A CLOSED 25
N MI DIAMETER EYE. THE INTENSITY IS BEING HELD AT 65 KT FOR THIS
ADVISORY...WHICH COULD BE A LITTLE LOW BASED ON SOME OF THE DAMAGE
REPORTS THAT HAVE BEEN RECEIVED FROM HAM RADIO OPERATORS ON ST.
LUCIA AND ST. VINCENT.

THE INITIAL MOTION ESTIMATE IS 290/09. TOMAS REMAINS ON TRACK...
AND THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR
REASONING. THE LOW- TO MID-LEVEL RIDGE TO THE NORTH OF TOMAS IS
EXPECTED TO CONTINUE TO BUILD WESTWARD ACROSS THE GREATER ANTILLES
FOR THE NEXT 96 HOURS...WHICH SHOULD KEEP TOMAS ON A WEST-NORTHWEST
TO WESTWARD TRACK. HOWEVER...A BROAD LONGWAVE TROUGH CURRENTLY
ALONG THE U.S. WEST COAST IS EXPECTED TO MOVE EASTWARD AND THEN
SOUTHEASTWARD INTO THE SOUTHEASTERN UNITED STATES...AND PINCH OFF A
CLOSED LOW OVER THE GULF OF MEXICO AND SOUTHEASTERN MEXICO BY 120
HOURS. THE STRONG SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE
AFOREMENTIONED TROUGH AND LOW IS EXPECTED TO RESULT IN A
SIGNIFICANT EROSION OF THE WESTERN PORTION OF THE GREATER ANTILLES
RIDGE AND CAUSE THE STEERING CURRENTS ACROSS THE WESTERN AND
CENTRAL CARIBBEAN SEA TO WEAKEN...ALLOWING TOMAS TO SLOW DOWN
CONSIDERABLY AND BEGIN TO MOVE POLEWARD. MOST OF THE MODEL GUIDANCE
IS IN GOOD AGREEMENT ON THIS GENERAL TRACK SCENARIO EXCEPT FOR
SPEED DIFFERENCES. THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE OF
THE PREVIOUS ADVISORY TRACK...AND REMAINS ALONG THE SOUTHERN EDGE
OF THE NHC GUIDANCE ENVELOPE...BUT NOT AS FAR SOUTH AS THE GFS AND
ECMWF MODELS.
 
WITH A CLOSED EYE AND A FAVORABLE UPPER-LEVEL ENVIRONMENT...TOMAS IS
FORECAST TO STRENGTHEN FOR THE NEXT 24 HOURS OR SO BEFORE WEAK
WESTERLY 400-300 MB WINDS UNDERCUT THE IMPRESSIVE OUTFLOW LAYER AND
ENTRAINMENT OF DRY MID-LEVEL AIR FROM THE WEST COMBINE TO INTERRUPT
THE STRENGTHENING PROCESS. HOWEVER...BY 48-72 HOURS...ENVIRONMENTAL
CONDITIONS ARE FORECAST TO IMPROVE...WHICH SHOULD ALLOW TOMAS TO
RESUME STEADY INTENSIFICATION. THE GFS-BASED SHIPS AND LGEM MODELS
ARE FORECASTING STEADY WEAKENING AFTER 48 HOURS...BUT THAT IS
BELIEVED TO BE DUE TO ERRONEOUS MODEL-INDUCED SOUTHWESTERLY
VERTICAL SHEAR AFFECTING TOMAS AS A RESULT OF THE OFFICIAL FORECAST
TRACK BEING ABOUT 120 N MI NORTH OF THE LARGE SCALE UPPER-LEVEL
ANTICYCLONE DEPICTED IN THE GFS MODEL. THE INTENSITY FORECAST
REMAINS ABOVE THE SHIPS/LGEM MODELS...AND IS SIMILAR TO THE
PREVIOUS FORECAST AND LAST TWO GFDL MODEL RUNS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/2100Z 13.5N  61.4W    65 KT
 12HR VT     31/0600Z 14.0N  63.4W    75 KT
 24HR VT     31/1800Z 14.5N  65.7W    80 KT
 36HR VT     01/0600Z 14.9N  67.9W    80 KT
 48HR VT     01/1800Z 15.2N  69.7W    85 KT
 72HR VT     02/1800Z 15.7N  72.4W    90 KT
 96HR VT     03/1800Z 16.0N  74.0W    95 KT
120HR VT     04/1800Z 16.5N  74.5W   100 KT
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 302202
TCDAT1
HURRICANE TOMAS SPECIAL DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
600 PM AST SAT OCT 30 2010
 
REPORTS FROM THE METEOROLOGICAL SERVICE OF ST. LUCIA INDICATE THAT
TOMAS HAS STRENGTHENED...WITH MAXIMUM WINDS OF 80 KT.  THIS SPECIAL
ADVISORY IS ISSUED TO INCREASE THE INITIAL AND FORECAST INTENSITY
OF THE HURRICANE.  NO OTHER CHANGES TO THE FORECAST HAVE BEEN MADE. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/2200Z 13.5N  61.6W    80 KT
 12HR VT     31/0600Z 14.0N  63.4W    85 KT
 24HR VT     31/1800Z 14.5N  65.7W    90 KT
 36HR VT     01/0600Z 14.9N  67.9W    90 KT
 48HR VT     01/1800Z 15.2N  69.7W    95 KT
 72HR VT     02/1800Z 15.7N  72.4W    95 KT
 96HR VT     03/1800Z 16.0N  74.0W    95 KT
120HR VT     04/1800Z 16.5N  74.5W   100 KT
 
$$
FORECASTER BERG/FRANKLIN
 

WTNT41 KNHC 310246
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM AST SAT OCT 30 2010
 
THE STRUCTURE OF TOMAS HAS CHANGED LITTLE SINCE THE TIME THE ST.
LUCIA WEATHER SERVICE REPORTED SUSTAINED WINDS ON THAT ISLAND OF AT
LEAST 80 KT AROUND 2130 UTC.  AN EYE HAS NOT BECOME ESTABLISHED ON
INFRARED SATELLITE IMAGERY...ALTHOUGH IT IS WELL DEFINED IN RADAR
DATA FROM MARTINIQUE.  THE INITIAL INTENSITY IS KEPT AT 80 KT SINCE
THERE ARE NO OBVIOUS RECENT CHANGES...BUT IT IS POSSIBLE THIS COULD
BE A BIT CONSERVATIVE.  AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE TOMAS LATER TONIGHT.
 
THE INITIAL MOTION IS 285/8.  THE CYCLONE IS EXPECTED TO
GRADUALLY GAIN LATITUDE FOR THE NEXT 48 HOURS OR SO DUE TO A MID-
TO UPPER-LEVEL TROUGH THAT IS CURRENTLY LOCATED OVER THE SOUTHWEST
ATLANTIC.  THE TRACK GUIDANCE IS IN GENERALLY GOOD AGREEMENT ON
THIS SOLUTION...BUT THERE IS MUCH GREATER SPREAD AFTER 48 HOURS.
THE GFS...ECMWF...UKMET...AND GFDL SUPPORT A STRONGER MID-LEVEL
RIDGE OVER THE GREATER ANTILLES AND MOVE TOMAS ON A WESTWARD OR
JUST SOUTH OF WESTWARD MOTION ON DAYS 2-4.  THE NOGAPS AND GFDN
SHOW TOMAS MOVING WELL NORTH OF HISPANIOLA BY DAY 5...AND THE HWRF
SHOWS THE CYCLONE STALLING OVER THE EASTERN CARIBBEAN SEA.  THE
LATTER THREE MODELS APPEAR TO BE OUTLIERS.  THE NEW OFFICIAL
FORECAST IS JUST A LITTLE SOUTH OF THE PREVIOUS FORECAST TO COME
INTO BETTER AGREEMENT WITH THE CONSENSUS OF THE MORE SOUTHERN BATCH
OF MODELS.
 
THERE CONTINUES TO BE LOW CONFIDENCE IN THE INTENSITY FORECAST.
NONE OF THE INTENSITY MODELS SHOW MUCH STRENGTHENING BEYOND ABOUT
90 KT.  THE 200-MB FLOW OVER THE CARIBBEAN SEA SHOULD BE FAVORABLE
FOR STRENGTHENING...ESPECIALLY IF TOMAS MAINTAINS A MORE
SOUTHERN COURSE.  HOWEVER...CROSS-SECTION ANALYSES OF THE GUIDANCE
DOES INDICATE THAT THE CYCLONE VORTEX COULD BECOME A LITTLE TILTED
OVER THE NEXT 48 HOURS OR SO...POSSIBLY DUE TO SHEAR BELOW THE
OUTFLOW LAYER.  BECAUSE OF THESE MIXED SIGNALS...THE OFFICIAL
INTENSITY FORECAST ONLY SHOWS MODEST STRENGTHENING THROUGH 24 HOURS
AND ESSENTIALLY HOLDS THE INTENSITY FAIRLY STEADY THEREAFTER.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/0300Z 13.6N  62.1W    80 KT
 12HR VT     31/1200Z 14.0N  63.8W    90 KT
 24HR VT     01/0000Z 14.6N  65.9W    95 KT
 36HR VT     01/1200Z 14.9N  68.0W    95 KT
 48HR VT     02/0000Z 15.0N  69.7W    95 KT
 72HR VT     03/0000Z 15.0N  72.5W    95 KT
 96HR VT     04/0000Z 15.5N  74.0W   100 KT
120HR VT     05/0000Z 16.0N  74.5W   100 KT
 
$$
FORECASTER BERG/FRANKLIN
 

WTNT41 KNHC 310843
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM AST SUN OCT 31 2010

DATA FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT...ALONG
WITH SATELLITE AND RADAR IMAGERY...INDICATE THAT TOMAS HAS BECOME
BETTER ORGANIZED IN THE PAST FEW HOURS. THE INITIAL INTENSITY OF 85
KT IS BASED ON A 700-MB FLIGHT LEVEL WIND MAXIMUM OF 97 KT AND A
MAXIMUM SFMR READING OF 85 KT. HOWEVER...DROPSONDE DATA FROM THE
AIRCRAFT AND A 0350 UTC TRMM PASS INDICATE THAT THE VORTEX IS
TILTED NORTHEASTWARD WITH HEIGHT. THIS SUGGESTS THAT SOUTHWESTERLY
SHEAR IS IMPACTING THE CYCLONE AS SEEN IN THE SHIPS MODEL ANALYSIS
WHICH IS BASED ON ATMOSPHERIC FIELDS FROM THE GFS MODEL. IN THE
SHORT TERM...THE SHIPS...LGEM...AND GFDL ALL SHOW SOME ADDITIONAL
INTENSIFICATION...AND SO DOES THE OFFICIAL FORECAST. FROM 24 TO 72
HOURS...THE SHIPS MODEL SHOWS THE SHEAR INCREASING...AND ALL OF THE
INTENSITY GUIDANCE WEAKENS TOMAS. ADDITIONALLY...THE GFS AND ECMWF
SHOW THE MID-LEVEL VORTEX ASSOCIATED WITH TOMAS WEAKENING DURING
THIS PERIOD. GIVEN THIS...THE OFFICIAL FORECAST WILL SHOW A SLIGHT
DIP IN THE INTENSITY AT 48 AND 72 HOURS...BUT REMAINS WELL ABOVE
ALL OF THE GUIDANCE. AROUND 96 HOURS...THE SHEAR MAY DECREASE AND
ALLOW FOR SOME STRENGTHENING...AS INDICATED BY THE LGEM. 

BASED ON RECENT FIXES TOMAS IS A BIT NORTH OF THE PREVIOUS TRACK
FORECAST AND THE LONG-TERM INITIAL MOTION ESTIMATE IS 290/7. TOMAS
IS CURRENTLY LOCATED SOUTH OF A MID-LEVEL TROUGH SITUATED OVER THE
SOUTHWEST ATLANTIC. AS THIS TROUGH MOVES EASTWARD...A MID-LEVEL
RIDGE BUILDS NORTH OF TOMAS AND SHOULD RESULT IN A TURN TOWARD THE
WEST IN 2 OR 3 DAYS. LATE IN THE PERIOD...THE RIDGE BREAKS DOWN AS
A LARGE DEEP-LAYER TROUGH MOVES INTO EASTERN NORTH AMERICA...
RESULTING IN A SLOWER FORWARD SPEED OF THE CYCLONE AND SOME GAIN IN
LATITUDE. HOWEVER...THE MODEL SPREAD IS QUITE LARGE AT DAYS 4 AND 5
DUE TO DIFFERENCES IN THE TIMING AND SHARPNESS OF THE NORTHWARD
TURN AS TOMAS INTERACTS WITH THE TROUGH. THE NEW NHC TRACK IS A
LITTLE NORTH OF THE PREVIOUS ONE DUE TO THE INITIAL POSITION...BUT
IS ON THE SOUTH SIDE OF THE GUIDANCE SUITE IN DEFERENCE TO THE
GFS...ECMWF...UKMET AND GFDL MODELS...WHICH ARE ALL EVEN FARTHER
SOUTH. AT DAY 5...A SLOW NORTH-NORTHWESTWARD MOTION IS SHOWN...BUT
CONFIDENCE IN THE DETAILS OF THE TRACK FORECAST ARE LOWER THAN
USUAL AT THE END OF THE PERIOD. 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/0900Z 14.0N  62.9W    85 KT
 12HR VT     31/1800Z 14.4N  64.3W    95 KT
 24HR VT     01/0600Z 14.8N  66.4W    95 KT
 36HR VT     01/1800Z 15.1N  68.4W    95 KT
 48HR VT     02/0600Z 15.1N  70.0W    90 KT
 72HR VT     03/0600Z 15.0N  72.0W    90 KT
 96HR VT     04/0600Z 15.5N  73.5W   100 KT
120HR VT     05/0600Z 16.5N  74.0W   100 KT
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 311444
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM AST SUN OCT 31 2010
 
DEEP CONVECTION ASSOCIATED WITH TOMAS HAS GENERALLY DECREASED DURING
THE LAST FEW HOURS AND BANDING FEATURES HAVE BECOME A LITTLE LESS
ORGANIZED. IN ADDITION...RECENT MICROWAVE IMAGES NO LONGER SHOW AN
EYE. BASED ON THIS...THE INITIAL WIND SPEED IS LOWERED TO 80
KT...WHICH IS A BLEND OF THE LATEST SUBJECTIVE AND OBJECTIVE
SATELLITE INTENSITY ESTIMATES. THE NEXT AIR FORCE RESERVE
RECONNAISSANCE AIRCRAFT SHOULD PROVIDE A BETTER ASSESSMENT OF THE
INTENSITY EARLY THIS AFTERNOON.
 
THE INITIAL MOTION ESTIMATE IS 285/8.  A GENERAL WESTWARD TO
WEST-NORTHWESTWARD MOTION AT ABOUT THE SAME SPEED IS EXPECTED
DURING THE NEXT COUPLE OF DAYS AS MID-LEVEL RIDGING REMAINS IN
PLACE TO THE NORTH OF TOMAS.  SOME OF THE MODELS EVEN SHOW A SOUTH
OF WEST MOTION DURING THAT TIME.  IN ABOUT 3 DAYS...THE CYCLONE IS
EXPECTED TO SLOW DOWN AS A LARGE MID- TO UPPER-LEVEL LOW MOVES OVER
THE GULF OF MEXICO...CAUSING THE RIDGE TO ERODE.  TOMAS IS FORECAST
TO GRADUALLY TURN TOWARD THE NORTH IN 4 TO 5 DAYS AS IT FEELS THE
INFLUENCE OF SOUTHERLY FLOW TO THE EAST OF THE TROUGH.  THE LATEST
MODEL GUIDANCE HAS CHANGED LITTLE FROM THE LAST CYCLE...AND THE
OFFICIAL FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS TRACK.
 
ALTHOUGH TOMAS LIES OVER AN AREA OF HIGH OCEANIC HEAT CONTENT...
MODERATE SOUTHWESTERLY SHEAR AND SOME MID-LEVEL DRY AIR AS SHOWN BY
MODEL CROSS SECTIONS COULD BE A LIMITING FACTOR FOR INTENSIFICATION
DURING THE NEXT COUPLE OF DAYS.  IN FACT...SEVERAL OF THE RELIABLE
MODELS...INCLUDING THE GFS...ECMWF...AND GFDL...SHOW THE VORTEX
TILTING TO THE NORTHEAST WITH HEIGHT.  THIS RESULTS IN THE
WEAKENING OF THE HURRICANE IN THOSE MODELS DURING THE NEXT COUPLE
OF DAYS.  THE OFFICIAL FORECAST HAS BEEN NUDGED DOWNWARD THROUGH 48
HOURS BUT REMAINS HIGHER THAN ALL OF THE INTENSITY GUIDANCE DURING
THAT TIME. A MORE FAVORABLE UPPER-LEVEL WIND PATTERN IS EXPECTED
DURING THE 3 TO 5 DAY TIME FRAME...AND THAT SHOULD ALLOW FOR STEADY
STRENGTHENING.
 
ALTHOUGH TROPICAL STORM WARNINGS FOR THE WINDWARD ISLANDS HAVE BEEN
DISCONTINUED...THE THREAT OF HEAVY RAINFALL IS EXPECTED TO CONTINUE
OVER MUCH OF THE LESSER ANTILLES THROUGH TONIGHT.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/1500Z 14.0N  63.7W    80 KT
 12HR VT     01/0000Z 14.5N  65.1W    75 KT
 24HR VT     01/1200Z 14.9N  67.2W    75 KT
 36HR VT     02/0000Z 15.0N  69.1W    75 KT
 48HR VT     02/1200Z 15.0N  70.6W    75 KT
 72HR VT     03/1200Z 15.0N  72.5W    85 KT
 96HR VT     04/1200Z 15.5N  73.5W    95 KT
120HR VT     05/1200Z 17.0N  73.5W   100 KT
 
$$
FORECASTER CANGIALOSI/BROWN
 

WTNT41 KNHC 312031
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM AST SUN OCT 31 2010
 
DATA FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATE THAT
TOMAS HAS WEAKENED A LITTLE MORE.  THE AIRCRAFT REPORTED A MAXIMUM
850 MB FLIGHT-LEVEL WIND OF 74 KT...AN SFMR SURFACE WIND OF 64
KT...AND A MINIMUM PRESSURE OF 994 MB.  THESE DATA SUPPORT
MAINTAINING TOMAS AS A HURRICANE WITH AN INITIAL WIND SPEED OF 65
KT.
 
THE INITIAL MOTION IS SLIGHTLY TO THE LEFT AND A LITTLE FASTER THAN
BEFORE...280/10.  TOMAS IS FORECAST TO CONTINUE MOVING WESTWARD FOR
THE NEXT COUPLE OF DAYS AS IT REMAINS SOUTH OF A MID-LEVEL RIDGE.
BEYOND THAT TIME...THE CYCLONE IS EXPECTED TO SLOW DOWN AND
GRADUALLY TURN TOWARD THE NORTH AS THE STEERING CURRENTS WEAKEN DUE
TO A LARGE MID- TO UPPER-LEVEL TROUGH MOVING ACROSS THE GULF OF
MEXICO.  ALTHOUGH THE TRACK MODEL GUIDANCE IS IN FAIR AGREEMENT IN
THE EVOLUTION OF THE LARGE-SCALE PATTERN...THERE ARE CONSIDERABLE
DIFFERENCES AS TO WHERE AND WHEN THE NORTHWARD TURN OCCURS.  THE
OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ONE FOR THE NEXT 3 TO
4 DAYS...AND THEN LIES A LITTLE TO THE RIGHT OF THE LAST TRACK TO
COME INTO BETTER AGREEMENT WITH THE LATEST GUIDANCE.  THIS TRACK
FORECAST IS CLOSE TO A CONSENSUS OF THE GFS...GFDL...ECMWF...AND
UKMET MODELS. IT SHOULD BE NOTED THAT CONFIDENCE IN THE LONG-TERM
FORECAST POINTS ARE OF LOWER CONFIDENCE THAN NORMAL.
 
SOME ADDITIONAL WEAKENING SEEMS LIKELY DURING THE NEXT DAY OR TWO AS
SOUTHWESTERLY SHEAR OF 20-25 KT AND SOME MID-LEVEL DRY AIR CONTINUE
TO IMPACT THE CYCLONE.  THE OFFICIAL FORECAST FOLLOWS THE TREND IN
THE GUIDANCE AND IS ONCE AGAIN ADJUSTED DOWNWARD...BRINGING TOMAS
BELOW HURRICANE STRENGTH WITHIN THE NEXT 12 HOURS.  BEYOND A COUPLE
OF DAYS...THE SHEAR IS EXPECTED TO LESSEN WHILE TOMAS REMAINS OVER
FAVORABLE OCEANIC CONDITIONS.  ALL OF THE INTENSITY MODELS RESPOND
AND SHOW THE SYSTEM INTENSIFYING IN THE 3 TO 5 DAY RANGE...AND THE
OFFICIAL FORECAST FOLLOWS SUIT AND IS AT THE HIGH END OF THE
GUIDANCE THROUGHOUT THE FORECAST PERIOD.
 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/2100Z 14.4N  64.9W    65 KT
 12HR VT     01/0600Z 14.7N  66.4W    60 KT
 24HR VT     01/1800Z 15.0N  68.3W    55 KT
 36HR VT     02/0600Z 15.0N  69.9W    55 KT
 48HR VT     02/1800Z 15.0N  71.3W    60 KT
 72HR VT     03/1800Z 15.3N  72.5W    65 KT
 96HR VT     04/1800Z 16.0N  73.0W    80 KT
120HR VT     05/1800Z 18.5N  72.5W    90 KT...INLAND
 
$$
FORECASTER CANGIALOSI/BROWN
 

WTNT41 KNHC 010234
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM AST SUN OCT 31 2010
 
RECENT MICROWAVE DATA...PARTICULARLY A 0045 UTC SSMIS PASS...
INDICATE THAT THE LOW-LEVEL CENTER OF TOMAS IS NOW LOCATED ABOUT
140 N MI TO THE WEST OF THE DEEP CONVECTION AND HAS BEEN MOVING A
LITTLE SOUTH OF DUE WEST.  DVORAK ESTIMATES HAVE DECREASED TO
T3.0/4.0 FROM TAFB...T2.5/3.5 FROM SAB...AND T3.4/4.3 FROM THE
ADT...AND THE INITIAL INTENSITY IS THEREFORE LOWERED TO 55 KT FOR
THIS ADVISORY.  THIS INTENSITY COULD BE A LITTLE GENEROUS...BUT
ADDITIONAL ADJUSTMENTS CAN BE MADE WHEN THE AIR FORCE HURRICANE
HUNTER AIRCRAFT INVESTIGATES THE CYCLONE LATER TONIGHT.

SIGNIFICANT MODIFICATIONS HAVE BEEN REQUIRED TO THE INTENSITY
FORECAST ON THIS ADVISORY.  STRONG SOUTHWESTERLY SHEAR BELOW THE
OUTFLOW LAYER IS EXPECTED TO CONTINUE TO AFFECT TOMAS FOR THE NEXT
48 HOURS...AS SHOWN BY THE SHIPS GUIDANCE...AND ALL THE INTENSITY
MODELS ARE SHOWING CONTINUED WEAKENING DURING THAT TIME.  THE
OFFICIAL FORECAST HAS BEEN ADJUSTED DOWNWARD...LEVELING THE
INTENSITY AT 40 KT BETWEEN 24 AND 48 HOURS.  THIS IS STILL ABOVE
MOST OF THE INTENSITY GUIDANCE...AND IT IS NOT OUT OF THE QUESTION
THAT TOMAS COULD WEAKEN MORE THAN INDICATED IN THE OFFICIAL
FORECAST.  THE SHEAR IS EXPECTED TO RELAX AFTER 72 HOURS...AND
THERE WILL BE AN OPPORTUNITY FOR TOMAS TO RESTRENGTHEN...POSSIBLY
BACK TO HURRICANE INTENSITY...OVER THE CENTRAL CARIBBEAN SEA.

NOW THAT THE LOW- AND MID-LEVEL CIRCULATIONS OF TOMAS HAVE BECOME
INCREASINGLY DECOUPLED...THE LOW-LEVEL CENTER HAS ACCELERATED OVER
THE PAST FEW HOURS WITH AN INITIAL MOTION ESTIMATED TO BE 270/13. 
THE SOUTHWESTWARD ADJUSTMENT OF THE INITIAL POSITION HAS CAUSED THE
NEW FORECAST TRACK TO BE A LITTLE SOUTH AND FASTER THAN THE
PREVIOUS FORECAST.  THE TRACK GUIDANCE IS IN RELATIVELY GOOD
AGREEMENT ON THE FUTURE TRACK OF TOMAS...BUT THERE CONTINUES TO BE
SPEED DIFFERENCES MAINLY ON DAYS 4 AND 5 WHEN A DEEP MID-LATITUDE
TROUGH SWEEPS ACROSS THE GULF OF MEXICO AND NORTHWESTERN CARIBBEAN. 
THE GFDN AND HWRF ARE STILL THE FASTEST MODELS...BUT THEY HAVE BEEN
JOINED BY THE ECMWF...MAKING A FASTER SCENARIO A LITTLE MORE
CREDIBLE BY DAY 5.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0300Z 14.2N  66.5W    55 KT
 12HR VT     01/1200Z 14.4N  68.1W    45 KT
 24HR VT     02/0000Z 14.7N  69.8W    40 KT
 36HR VT     02/1200Z 14.8N  71.6W    40 KT
 48HR VT     03/0000Z 14.8N  73.1W    40 KT
 72HR VT     04/0000Z 15.1N  74.5W    50 KT
 96HR VT     05/0000Z 16.5N  74.5W    65 KT
120HR VT     06/0000Z 20.0N  72.5W    70 KT
 
$$
FORECASTER BERG
 

WTNT41 KNHC 010834
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM AST MON NOV 01 2010
 
WESTERLY VERTICAL SHEAR...WHICH APPEARS TO BE PRIMARILY DUE TO THE
DIFFERENCES BETWEEN THE LOWER- AND MID-TROPOSPHERIC FLOW...
CONTINUES TO IMPACT TOMAS.  CONSEQUENTLY THE CYCLONE REMAINS HIGHLY
DECOUPLED AS THE LOW-LEVEL CENTER IS DISPLACED MORE THAN 100 N MI
WEST OF THE DEEP CONVECTION.  SFMR OBSERVATIONS FROM AN AIR FORCE
RECONNAISSANCE AIRCRAFT INDICATE THAT THE INTENSITY HAS DECREASED
TO NEAR 45 KT.  ADDITIONAL WEAKENING IS LIKELY AS 20 TO 25 KT OF
SHEAR SHOULD CONTINUE AFFECTING THE TROPICAL CYCLONE FOR ABOUT
ANOTHER 24 HOURS.  THEREAFTER...THE SHIPS/LGEM GUIDANCE INDICATES
THAT THE SHEAR SHOULD RELAX WHICH WOULD ALLOW FOR TOMAS TO REGAIN
STRENGTH.  THE OFFICIAL INTENSITY FORECAST FOLLOWS THIS SCENARIO
AND IS CLOSE TO THE CONSENSUS OF THE NUMERICAL INTENSITY GUIDANCE.
THIS IS WELL ABOVE THE LGEM GUIDANCE AND BELOW THE MORE AGGRESSIVE
GFDL MODEL FORECAST.  IT SHOULD BE NOTED THAT THERE IS CONSIDERABLE
UNCERTAINTY AS TO HOW STRONG TOMAS WILL GET IN THE LATTER PART OF
THE FORECAST PERIOD.
 
AIRCRAFT AND SATELLITE FIXES INDICATE THAT THE MOTION IS JUST
SLIGHTLY SOUTH OF DUE WEST OR 280/12.  A WEAKENING LOW- TO
MID-LEVEL RIDGE TO THE NORTH OF THE STORM SHOULD PRODUCE A
GENERALLY WESTWARD MOTION WITH DECELERATION OVER THE NEXT 48 HOURS
OR SO.  IN 72 TO 96 HOURS...THE GLOBAL MODELS DEPICT A LARGE
AMPLITUDE MID-TROPOSPHERIC TROUGH MOVING EASTWARD ACROSS THE GULF OF
MEXICO.  THE FLOW AHEAD OF THIS FEATURE SHOULD TURN TOMAS NORTHWARD
AND NORTH-NORTHEASTWARD WITH AN INCREASE IN FORWARD SPEED.  THE
OFFICIAL FORECAST IS SOMEWHAT SOUTH OF THE PREVIOUS ONE IN THE
EARLY PART OF THE FORECAST PERIOD MAINLY DUE TO THE SOUTHWARD SHIFT
IN RECENT FIXES.  AS NOTED EARLIER...THERE IS SOME AGREEMENT
AMONGST THE TRACK MODELS ON THE GENERAL TRAJECTORY OF TOMAS DURING
THE LATTER PART OF THE FORECAST PERIOD BUT THERE ARE STILL
SUBSTANTIAL DIFFERENCES IN THE PREDICTED FORWARD SPEEDS.  DUE TO
THE UNCERTAINTIES ONE SHOULD NOT FOCUS ON THE EXACT FORECAST
TRACK...PARTICULARLY THE TIMING OF THE 4 AND 5 DAY POINTS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0900Z 13.8N  67.7W    45 KT
 12HR VT     01/1800Z 14.1N  69.3W    40 KT
 24HR VT     02/0600Z 14.3N  71.3W    35 KT
 36HR VT     02/1800Z 14.4N  72.9W    40 KT
 48HR VT     03/0600Z 14.6N  73.9W    45 KT
 72HR VT     04/0600Z 15.5N  74.5W    55 KT
 96HR VT     05/0600Z 17.5N  74.0W    70 KT
120HR VT     06/0600Z 21.5N  71.5W    65 KT
 
$$
FORECASTER PASCH
 

WTNT41 KNHC 010841
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  13...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM AST MON NOV 01 2010

CORRECTED MOTION TO 260/12
 
WESTERLY VERTICAL SHEAR...WHICH APPEARS TO BE PRIMARILY DUE TO THE
DIFFERENCES BETWEEN THE LOWER- AND MID-TROPOSPHERIC FLOW...
CONTINUES TO IMPACT TOMAS.  CONSEQUENTLY THE CYCLONE REMAINS HIGHLY
DECOUPLED AS THE LOW-LEVEL CENTER IS DISPLACED MORE THAN 100 N MI
WEST OF THE DEEP CONVECTION.  SFMR OBSERVATIONS FROM AN AIR FORCE
RECONNAISSANCE AIRCRAFT INDICATE THAT THE INTENSITY HAS DECREASED
TO NEAR 45 KT.  ADDITIONAL WEAKENING IS LIKELY AS 20 TO 25 KT OF
SHEAR SHOULD CONTINUE AFFECTING THE TROPICAL CYCLONE FOR ABOUT
ANOTHER 24 HOURS.  THEREAFTER...THE SHIPS/LGEM GUIDANCE INDICATES
THAT THE SHEAR SHOULD RELAX WHICH WOULD ALLOW FOR TOMAS TO REGAIN
STRENGTH.  THE OFFICIAL INTENSITY FORECAST FOLLOWS THIS SCENARIO
AND IS CLOSE TO THE CONSENSUS OF THE NUMERICAL INTENSITY GUIDANCE.
THIS IS WELL ABOVE THE LGEM GUIDANCE AND BELOW THE MORE AGGRESSIVE
GFDL MODEL FORECAST.  IT SHOULD BE NOTED THAT THERE IS CONSIDERABLE
UNCERTAINTY AS TO HOW STRONG TOMAS WILL GET IN THE LATTER PART OF
THE FORECAST PERIOD.
 
AIRCRAFT AND SATELLITE FIXES INDICATE THAT THE MOTION IS JUST
SLIGHTLY SOUTH OF DUE WEST OR 260/12.  A WEAKENING LOW- TO
MID-LEVEL RIDGE TO THE NORTH OF THE STORM SHOULD PRODUCE A
GENERALLY WESTWARD MOTION WITH DECELERATION OVER THE NEXT 48 HOURS
OR SO.  IN 72 TO 96 HOURS...THE GLOBAL MODELS DEPICT A LARGE
AMPLITUDE MID-TROPOSPHERIC TROUGH MOVING EASTWARD ACROSS THE GULF OF
MEXICO.  THE FLOW AHEAD OF THIS FEATURE SHOULD TURN TOMAS NORTHWARD
AND NORTH-NORTHEASTWARD WITH AN INCREASE IN FORWARD SPEED.  THE
OFFICIAL FORECAST IS SOMEWHAT SOUTH OF THE PREVIOUS ONE IN THE
EARLY PART OF THE FORECAST PERIOD MAINLY DUE TO THE SOUTHWARD SHIFT
IN RECENT FIXES.  AS NOTED EARLIER...THERE IS SOME AGREEMENT
AMONGST THE TRACK MODELS ON THE GENERAL TRAJECTORY OF TOMAS DURING
THE LATTER PART OF THE FORECAST PERIOD BUT THERE ARE STILL
SUBSTANTIAL DIFFERENCES IN THE PREDICTED FORWARD SPEEDS.  DUE TO
THE UNCERTAINTIES ONE SHOULD NOT FOCUS ON THE EXACT FORECAST
TRACK...PARTICULARLY THE TIMING OF THE 4 AND 5 DAY POINTS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0900Z 13.8N  67.7W    45 KT
 12HR VT     01/1800Z 14.1N  69.3W    40 KT
 24HR VT     02/0600Z 14.3N  71.3W    35 KT
 36HR VT     02/1800Z 14.4N  72.9W    40 KT
 48HR VT     03/0600Z 14.6N  73.9W    45 KT
 72HR VT     04/0600Z 15.5N  74.5W    55 KT
 96HR VT     05/0600Z 17.5N  74.0W    70 KT
120HR VT     06/0600Z 21.5N  71.5W    65 KT
 
$$
FORECASTER PASCH
 

WTNT41 KNHC 011438
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM AST MON NOV 01 2010
 
TOMAS IS A HIGHLY SHEARED TROPICAL CYCLONE.  THE LOW-LEVEL CENTER IS
DISPLACED MORE THAN 100 MILES TO THE WEST OF THE MAIN AREA OF DEEP
CONVECTION. HOWEVER...A SMALL AREA OF THUNDERSTORMS HAS RECENTLY
FORMED JUST TO THE NORTHEAST OF THE CENTER. SATELLITE INTENSITY
ESTIMATES CONTINUE TO FALL...AND THE INITIAL INTENSITY IS LOWERED
TO 40 KT FOR THIS ADVISORY.
 
THE STORM CONTINUES TO MOVE SOUTH OF DUE WEST...AND THE LATEST
12-HOUR INITIAL MOTION ESTIMATE IS 255/12. A GENERAL WESTWARD
HEADING WITH A DECREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT
24 TO 36 HOURS AS THE CYCLONE IS STEERED BY LOW- TO MID-LEVEL
EASTERLY FLOW. BY WEDNESDAY...A LARGE MID- TO UPPER-LEVEL LOW IS
EXPECTED TO MOVE EASTWARD INTO THE GULF OF MEXICO. GLOBAL MODELS
ARE IN AGREEMENT IN SHOWING THIS LOW OR TROUGH SWINGING ACROSS THE
GULF OF MEXICO AND INTO THE NORTHWESTERN CARIBBEAN. AS THIS
OCCURS...SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE TROUGH WILL
WEAKEN THE STEERING CURRENTS AND THEN CAUSE TOMAS TO TURN TOWARD
THE NORTH AND NORTHEAST IN 4 TO 5 DAYS. THE LATEST TRACK MODEL
GUIDANCE HAS SHIFTED A LITTLE TO THE LEFT...MAINLY DUE TO THE
RECENT SOUTHWESTWARD MOTION.  ALTHOUGH THE NEW OFFICIAL FORECAST IS
SOUTH OF THE PREVIOUS ONE FOR THE NEXT 3 DAYS...IT ENDS UP ON THE
PREVIOUS TRACK BY DAYS 4 AND 5.
 
SOUTHWESTERLY SHEAR OF ABOUT 20 KT AND DRY MID-LEVEL AIR COULD CAUSE
A LITTLE MORE WEAKENING DURING THE NEXT 24 HOURS.  AFTER THAT
TIME...THE SHEAR IS EXPECTED TO DECREASE AND THE OTHER ATMOSPHERIC
AND OCEANIC PARAMETERS SHOULD SUPPORT STRENGTHENING.  ALL OF
THE GUIDANCE SHOWS TOMAS RE-INTENSIFYING...ESPECIALLY BEYOND 48
HOURS...AND THE OFFICIAL FORECAST FOLLOWS THAT THEME. THE NEW WIND
SPEED FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE
INTENSITY MODEL CONSENSUS.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/1500Z 13.6N  68.7W    40 KT
 12HR VT     02/0000Z 13.7N  70.3W    35 KT
 24HR VT     02/1200Z 13.8N  72.1W    35 KT
 36HR VT     03/0000Z 14.0N  73.3W    40 KT
 48HR VT     03/1200Z 14.3N  74.2W    45 KT
 72HR VT     04/1200Z 15.2N  74.8W    55 KT
 96HR VT     05/1200Z 17.5N  74.0W    65 KT
120HR VT     06/1200Z 21.5N  71.5W    65 KT
 
$$
FORECASTER CANGIALOSI
 

WTNT41 KNHC 012045
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM AST MON NOV 01 2010
 
ALTHOUGH DEEP CONVECTION HAS INCREASED NEAR THE CENTER OF TOMAS
TODAY...IT IS POORLY ORGANIZED AND LACKS BANDING. VISIBLE SATELLITE
IMAGES SHOW A SERIES OF ARC CLOUDS PROPAGATING AWAY FROM THE
CONVECTIVE MASS...INDICATIVE OF DRY AIR NEAR THE CORE. AN ASCAT
PASS AROUND 1400 UTC SHOWED MAXIMUM WINDS IN THE 30-35 KT RANGE.
SINCE CONVECTION HAS INCREASED SINCE THAT TIME...THE INITIAL
INTENSITY IS HELD AT 40 KT...IN AGREEMENT WITH SATELLITE INTENSITY
ESTIMATES.

TOMAS IS STILL MOVING A LITTLE SOUTH OF DUE WEST...AND THE INITIAL
MOTION ESTIMATE IS 260/10. THE STORM IS EXPECTED TO MOVE GENERALLY
WESTWARD FOR THE NEXT DAY OR SO WITHIN EASTERLY FLOW TO THE SOUTH
OF A LOW- TO MID-LEVEL RIDGE. GLOBAL MODELS REMAIN IN GOOD
AGREEMENT IN SHOWING A STRONG DEEP-LAYER TROUGH MOVING ACROSS THE
GULF OF MEXICO AND INTO THE NORTHWESTERN CARIBBEAN BY MID TO LATE
WEEK. THIS SYNOPTIC PATTERN SHOULD CAUSE THE CYCLONE TO SLOW DOWN
AND THEN MAKE A TURN TOWARD THE NORTH IN ABOUT 3 DAYS.
THEREAFTER... A NORTHEASTWARD MOTION WITH AN INCREASE IN FORWARD
SPEED IS FORECAST AS TOMAS BECOMES EMBEDDED IN SOUTHWESTERLY FLOW
TO THE EAST OF THE TROUGH. THE LATEST GUIDANCE HAS SHIFTED TO THE
LEFT ONCE AGAIN THROUGH 72 HOURS....AND THE OFFICIAL FORECAST IS
ADJUSTED IN THAT DIRECTION. THE NEW TRACK FORECAST IS NEAR A BLEND
OF THE GFS AND ECMWF MODELS.

DRY MID-LEVEL AIR AND SOUTHWESTERLY SHEAR CONTINUE TO IMPACT THE
CYCLONE. THE STORM IS EXPECTED TO REMAIN IN THIS UNFAVORABLE
ENVIRONMENT FOR ANOTHER 12-24 HOURS...WHICH SHOULD PREVENT MUCH
STRENGTHENING. AFTER THAT TIME...ENVIRONMENTAL WINDS ARE
ANTICIPATED TO BECOME MORE CONDUCIVE AND MODEL CROSS SECTIONS
SUGGEST THAT THE ATMOSPHERE WILL MOISTEN. THIS ENVIRONMENT SHOULD
ALLOW THE STORM TO GAIN STRENGTH...AND THE OFFICIAL FORECAST HAS
BEEN ADJUSTED UPWARD TO BE IN AGREEMENT WITH THE SHIPS MODEL.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/2100Z 13.4N  69.7W    40 KT
 12HR VT     02/0600Z 13.4N  71.2W    40 KT
 24HR VT     02/1800Z 13.7N  73.0W    45 KT
 36HR VT     03/0600Z 14.0N  74.2W    50 KT
 48HR VT     03/1800Z 14.3N  74.9W    55 KT
 72HR VT     04/1800Z 15.1N  75.0W    65 KT
 96HR VT     05/1800Z 18.0N  73.5W    80 KT
120HR VT     06/1800Z 21.0N  71.0W    70 KT
 
$$
FORECASTER CANGIALOSI
 

WTNT41 KNHC 020234
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT MON NOV 01 2010
 
THERE HAS BEEN NO APPRECIABLE CHANGE TO THE STRUCTURE OF TOMAS OVER
THE PAST SEVERAL HOURS.  DEEP CONVECTION HAD DIMINISHED AT ONE
POINT THIS EVENING...BUT A LINEAR BAND HAS RECENTLY RE-DEVELOPED
ABOUT 60-90 N MI EAST OF THE LOW-LEVEL CENTER.  THE INITIAL
INTENSITY IS HELD AT 40 KT...WHICH IS CONSISTENT WITH SATELLITE
ESTIMATES OF T2.5/3.0 FROM TAFB AND T2.6/2.7 FROM THE OBJECTIVE
ADT.  ALTHOUGH WEST-SOUTHWESTERLY SHEAR CONTINUES TO IMPACT THE
CYCLONE...IT IS EXPECTED TO DECREASE IN 24-36 HOURS.  IN
ADDITION...THE MID-LEVEL RELATIVE HUMIDITY IS EXPECTED TO
INCREASE...AND TOMAS WILL BE MOVING OVER A REGION OF INCREASED
OCEAN HEAT CONTENT.  ALL THESE FACTORS SUGGEST THAT TOMAS SHOULD
RE-STRENGTHEN...AND THE INTENSITY MODELS ARE IN GENERALLY GOOD
AGREEMENT THAT IT COULD BECOME A HURRICANE AGAIN BY DAY 3.  THE
PREVIOUS FORECAST IS IN LINE WITH THE NEW INTENSITY GUIDANCE...AND
NO CHANGES WERE REQUIRED ON THIS ADVISORY.

RECENT MICROWAVE IMAGERY SUGGESTS THAT TOMAS HAS CEASED MOVING
SOUTH OF DUE WEST AND NOW HAS AN INITIAL MOTION OF 270/10.  TRACK
GUIDANCE INDICATES THAT TOMAS...IN ITS WEAKENED STATE...SHOULD
CONTINUE TO MOVE WESTWARD IN THE LOW-LEVEL FLOW FOR THE NEXT 36
HOURS OR SO.  ONCE THE CYCLONE BEGINS TO STRENGTHEN...THE DEEPER
VORTEX SHOULD BE STEERED NORTHWARD AND THEN NORTHEASTWARD IN THE
SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING MID- TO UPPER-LEVEL
TROUGH.  SINCE THE HWRF AND GFDN APPEAR TO BE NORTHERN OUTLIERS AND
THE NOGAPS DOES NOT EVEN PULL TOMAS OUT OF THE CARIBBEAN...THE
OFFICIAL FORECAST IS BASED ON A CONSENSUS OF THE GFS...ECMWF...
GFDL...AND UKMET.  THE GUIDANCE ENVELOPE HAS SHIFTED A BIT TO THE
WEST ON THIS CYCLE...MAINLY IN THE DAY 2 AND 3 TIME FRAME...AND THE
NEW OFFICIAL FORECAST FOLLOWS THAT TREND.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0300Z 13.5N  70.8W    40 KT
 12HR VT     02/1200Z 13.7N  72.5W    40 KT
 24HR VT     03/0000Z 13.9N  73.9W    45 KT
 36HR VT     03/1200Z 14.2N  74.9W    50 KT
 48HR VT     04/0000Z 14.6N  75.5W    55 KT
 72HR VT     05/0000Z 16.0N  75.5W    65 KT
 96HR VT     06/0000Z 18.5N  73.5W    80 KT...INLAND
120HR VT     07/0000Z 21.0N  70.5W    70 KT...OVER WATER
 
$$
FORECASTER BERG
 

WTNT41 KNHC 020837
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM EDT TUE NOV 02 2010

TOMAS HAS THE APPEARANCE OF A GRADUALLY STRENGTHENING TROPICAL
STORM.  OVERNIGHT...THERE HAS BEEN A SUBSTANTIAL INCREASE IN THE
ASSOCIATED DEEP CONVECTION.  ALTHOUGH MOST OF THE THUNDERSTORM
ACTIVITY IS OCCURRING OVER THE EASTERN AND NORTHEASTERN PORTIONS OF
THE CIRCULATION...DEEP CONVECTION HAS RECENTLY BEEN INCREASING NEAR
THE CENTER.  ENHANCED IR IMAGERY ALSO SUGGESTS SOME BANDING
FEATURES DEVELOPING OVER THE NORTHEAST QUADRANT.  ON THE FINAL PASS
OF AN AIR FORCE HURRICANE HUNTER PLANE OUTBOUND FROM THE CENTER
OVER THE NORTHEAST QUADRANT...THE MAXIMUM UNFLAGGED SFMR-MEASURED
SURFACE WIND SPEED WAS 44 KT.  THE INTENSITY IS ADJUSTED SLIGHTLY
UPWARD...TO 45 KT...ON THIS ADVISORY.  TOMAS IS FORECAST TO MOVE
OVER WATERS OF INCREASINGLY HIGH OCEANIC HEAT CONTENT AND ALTHOUGH
SOME SOUTHWESTERLY SHEAR WILL PROBABLY IMPACT THE SYSTEM...THE
SHEAR IS NOT LIKELY TO BECOME VERY STRONG FOR THE NEXT FEW DAYS. 
THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND
BRINGS TOMAS TO HURRICANE INTENSITY IN A COUPLE OF DAYS.  THIS IS
SIMILAR TO THE RELIABLE LGEM GUIDANCE BUT BELOW THE GFDL FORECAST
INTENSITY PREDICTION.
 
BASED ON THE HURRICANE HUNTER FIXES...THE STORM CONTINUES MOVING
WESTWARD...OR ABOUT 270/10.  THE TRACK FORECAST REASONING FOR THE
NEXT 3 TO 4 DAYS REMAINS THE SAME AS BEFORE.  TOMAS SHOULD BE
STEERED ALONG THE SOUTHERN AND SOUTHWESTERN PERIPHERY OF A LOW- TO
MID-LEVEL RIDGE FOR THE NEXT COUPLE OF DAYS.  BY 72-96 HOURS...THE
FLOW AHEAD OF A LARGE MID-TROPOSPHERIC TROUGH SHOULD TURN THE
DEEPENING CYCLONE SHARPLY NORTHWARD AND NORTH-NORTHEASTWARD.  BY
THE END OF THE FORECAST PERIOD...THE GLOBAL MODELS SUGGEST THAT THE
TROUGH COULD SWING NORTHEASTWARD AND NOT COMPLETELY PICK UP TOMAS. 
THEREFORE THERE IS A POSSIBILITY THAT THE TROPICAL CYCLONE COULD
LINGER NEAR NORTHERN HISPANIOLA FOR A DAY OR TWO...BEFORE THE
WESTERLIES EVENTUALLY CARRY IT FARTHER OUT INTO THE ATLANTIC.  THAT
POSSIBILITY...HOWEVER...IS NOT EXPLICITLY SHOWN IN THE OFFICIAL
TRACK FORECAST AT THIS TIME.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0900Z 13.5N  72.0W    45 KT
 12HR VT     02/1800Z 13.7N  73.1W    50 KT
 24HR VT     03/0600Z 14.0N  74.4W    55 KT
 36HR VT     03/1800Z 14.4N  75.3W    60 KT
 48HR VT     04/0600Z 15.0N  75.8W    65 KT
 72HR VT     05/0600Z 16.3N  75.2W    80 KT
 96HR VT     06/0600Z 19.0N  72.5W    70 KT...INLAND
120HR VT     07/0600Z 21.5N  70.0W    60 KT...OVER WATER
 
$$
FORECASTER PASCH
 

WTNT41 KNHC 021452
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT TUE NOV 02 2010
 
TOMAS HAS CERTAINLY BECOME BETTER ORGANIZED SINCE YESTERDAY...WITH A
LARGE AREA OF DEEP CONVECTION AND INCREASED BANDING SEEN IN
CONVENTIONAL SATELLITE AND MICROWAVE DATA.  HOWEVER...THE STORM HAS
CHANGED LITTLE IN ORGANIZATION SINCE THE RECONNAISSANCE AIRCRAFT
REPORTED SFMR SURFACE WINDS OF 45 KT AROUND 0800 UTC.  THEREFORE...
THE INITIAL INTENSITY IS HELD AT THAT VALUE...WHICH IS IN LINE WITH
THE LATEST DVORAK T-NUMBERS OF 2.5 AND 3.5 FROM SAB AND TAFB...
RESPECTIVELY.  THE NEXT AIR FORCE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE TOMAS THIS AFTERNOON. 
   
WESTERLY SHEAR CONTINUES TO RELAX AND THE MID-LEVEL ENVIRONMENT
APPEARS TO BE MOISTENING.  THESE ATMOSPHERIC CONDITIONS...COMBINED
WITH HIGH OCEANIC HEAT CONTENT...FAVOR INTENSIFICATION DURING THE
NEXT FEW DAYS...WHICH IS SHOWN BY MOST OF THE GUIDANCE.  IN
FACT...THE SHIPS RAPID INTENSIFICATION INDEX GIVES A 48 PERCENT
CHANCE OF A 30-KT INCREASE IN WIND SPEED DURING THE NEXT 24 HOURS.
THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD FROM THE PREVIOUS
ADVISORY AND IS NOW AT OR JUST ABOVE THE HIGH END OF THE INTENSITY
GUIDANCE.  AFTER A FEW DAYS...LAND INTERACTION...DRIER AIR...AND
SOME INCREASE IN SOUTHERLY SHEAR IS LIKELY TO CAUSE WEAKENING. 
 
THE INITIAL MOTION ESTIMATE IS A LITTLE SLOWER THAN BEFORE...270/9.
A TURN TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN
FORWARD SPEED IS FORECAST DURING THE NEXT 24-48 HOURS AS A STRONG
TROUGH MOVES EASTWARD ACROSS THE GULF OF MEXICO. AS A RESULT...
TOMAS IS EXPECTED TO TURN NORTHWARD AND NORTHEASTWARD BEYOND 48
HOURS IN DEEP-LAYER SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE
TROUGH. SEVERAL OF THE GLOBAL MODELS SUGGEST THAT THE TROUGH WILL
NOT COMPLETELY CAPTURE TOMAS AND THERE REMAINS A LARGE DISAGREEMENT
IN THE FUTURE POSITION OF THE CYCLONE AT DAYS 4 AND 5. THE OFFICIAL
FORECAST IS OF LOW CONFIDENCE DURING THAT TIME PERIOD AND IS NEAR A
CONSENSUS OF THE GFS...GFDL... UKMET...NOGAPS...AND ECMWF MODELS.
  
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS
THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY
RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/1500Z 13.5N  72.6W    45 KT
 12HR VT     03/0000Z 13.7N  73.8W    55 KT
 24HR VT     03/1200Z 14.1N  75.0W    65 KT
 36HR VT     04/0000Z 14.6N  75.8W    70 KT
 48HR VT     04/1200Z 15.2N  76.0W    80 KT
 72HR VT     05/1200Z 17.2N  74.9W    90 KT
 96HR VT     06/1200Z 20.0N  72.0W    65 KT
120HR VT     07/1200Z 22.5N  69.5W    60 KT
 
$$
FORECASTER CANGIALOSI/BROWN
 

WTNT41 KNHC 022047
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM EDT TUE NOV 02 2010
 
AN AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS FOUND THE
STORM WEAKER THAN IT WAS EARLY THIS MORNING...WITH A SOMEWHAT
ELONGATED CIRCULATION. MAXIMUM FLIGHT-LEVEL AND SFMR SURFACE WINDS
SUPPORT LOWERING THE INITIAL INTENSITY TO 35 KT. THE CONVECTIVE
STRUCTURE OF TOMAS HAS ALSO BECOME LESS ORGANIZED.
 
THE CONTINUED WEAKENING...OR AT LEAST LACK OF STRENGTHENING...OF
TOMAS IS LIKELY DUE TO MID-LEVEL DRY AIR...SOME WESTERLY
SHEAR...AND PERHAPS THE PROXIMITY TO SOUTH AMERICA.
HOWEVER...INTENSIFICATION STILL SEEMS LIKELY GIVEN THE EXPECTED
FAVORABLE ATMOSPHERIC ENVIRONMENT DURING THE NEXT FEW DAYS. THE
OFFICIAL FORECAST HAS BEEN ADJUSTED DOWNWARD FROM THE PREVIOUS ONE
FOR THE FIRST COUPLE OF DAYS...DUE TO THE LOWER INITIAL
INTENSITY...BUT IS OTHERWISE SIMILAR TO THE PREVIOUS ADVISORY.
 
AIRCRAFT AND SATELLITE FIXES INDICATE THAT TOMAS CONTINUES WESTWARD
AT AROUND 12 KT. THE TRACK FORECAST REASONING IS UNCHANGED FROM
EARLIER. A STRONG MID- TO UPPER-LEVEL TROUGH CURRENTLY MOVING INTO
THE WESTERN GULF OF MEXICO IS EXPECTED TO SWING EASTWARD INTO THE
NORTHWESTERN CARIBBEAN SEA. THIS PATTERN WILL CAUSE THE SYSTEM TO
SLOW DOWN AND TURN TOWARD THE NORTH IN THE NEXT 24 TO 48 HOURS.
TOMAS IS THEN FORECAST TO TRACK NORTHEASTWARD WITH SOME INCREASE IN
FORWARD SPEED IN THE 2 TO 4 DAY PERIOD. BY DAY 5...MOST OF THE
GLOBAL MODELS SHOW THE TROUGH FLATTENING AND LEAVING TOMAS BEHIND.
THE LATEST TRACK GUIDANCE HAS SHIFTED TO THE LEFT...AND THE
OFFICIAL FORECAST IS ADJUSTED IN THAT DIRECTION.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS
THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY
RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/2100Z 13.5N  74.6W    35 KT
 12HR VT     03/0600Z 13.8N  75.6W    40 KT
 24HR VT     03/1800Z 14.2N  76.6W    50 KT
 36HR VT     04/0600Z 14.7N  77.0W    60 KT
 48HR VT     04/1800Z 15.3N  76.7W    70 KT
 72HR VT     05/1800Z 18.1N  74.8W    85 KT
 96HR VT     06/1800Z 21.0N  72.5W    75 KT
120HR VT     07/1800Z 22.5N  70.5W    60 KT
 
$$
FORECASTER CANGIALOSI/BROWN
 

WTNT41 KNHC 030242
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT TUE NOV 02 2010
 
SATELLITE IMAGES INDICATE THAT OVERALL CONVECTION HAS DECREASED
DURING THE PAST SEVERAL HOURS...THOUGH A CURVED BAND HAS BECOME A
LITTLE BETTER-DEFINED RECENTLY.  MICROWAVE DATA SUGGEST THE CENTER
IS ON THE SOUTHEASTERN SIDE OF THAT BAND...AND REMNANTS OF THE OLD
MID-LEVEL CIRCULATION CAN BE SEEN NORTHWEST OF ARUBA.  SATELLITE
INTENSITY ESTIMATES VARY FROM 35-55 KT...AND NO CHANGE WILL BE MADE
TO THE INITIAL WIND SPEED OF 35 KT. AN AIR FORCE HURRICANE HUNTER
WILL BE IN THE AREA IN A FEW HOURS TO CHECK ON THE STATUS OF TOMAS.
 
LARGE-SCALE ENVIRONMENTAL PARAMETERS APPEAR TO BE RATHER FAVORABLE
FOR FUTURE INTENSIFICATION WITH LOW SHEAR AND VERY WARM WATER FOR
THE NEXT FEW DAYS.  IT IS UNCERTAIN...HOWEVER...IF TOMAS CAN TAKE
ADVANTAGE OF THESE CONDITIONS.  A LOOK AT GLOBAL MODEL CROSS-
SECTIONS SHOW A TILTED VORTEX INITIALLY...WITH THE GFS/UKMET
SUGGESTING A MORE FAVORABLE VERTICAL VORTEX STRUCTURE FOR
STRENGTHENING IN A DAY OR TWO.  THE ECMWF MODEL...WHICH WAS ONE
OF THE FEW MODELS THAT PREDICTED THE WEAKENING OF TOMAS IN THE
EASTERN CARIBBEAN...HAS A QUITE DIFFERENT SCENARIO WITH A GOOD DEAL
OF TILT REMAINING FOR THE NEXT FEW DAYS AND ONLY A MODEST INCREASE
IN WINDS UNTIL AFTER THE TROPICAL CYCLONE LEAVES THE CARIBBEAN. 
WITH SUCH DIVERGENCE IN THE GUIDANCE...THE NEW FORECAST IS ABOUT
THE SAME THE PREVIOUS ONE...A LITTLE HIGHER THAN THE MODEL
CONSENSUS.

AN UNCERTAIN INITIAL MOTION ESTIMATE IS 280/7.  A CONTINUED
SLOW-DOWN OF THE TROPICAL CYCLONE IS LIKELY AS RIDGING WEAKENS TO
THE NORTH OF TOMAS.  A DEEP LAYER LOW ENTERING THE GULF OF MEXICO
IS EXPECTED TO ACCELERATE AND TURN TOMAS TO THE NORTH AND NORTHEAST
ON THURSDAY.  WHILE THE MODELS TAKE VARIOUS SPEEDS AND ROUTES TO
GET THERE...THEY REMAIN FOCUSED IN THE DIRECTION OF SOUTHWESTERN
HAITI.  THE NHC FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT OF THE
PREVIOUS FORECAST DURING THE FIRST COUPLE OF DAYS...AND GENERALLY
LIES TO THE SOUTHEAST OF THE MODEL CONSENSUS.  THE HWRF AND GFDN
HAVE A RATHER DEEP AND INTENSE CIRCULATION...WHICH APPEAR TO BE
OUTLIERS AND BIASING TVCN...THE VARIABLE CONSENSUS MODEL...TOO FAR
TO THE NORTH.   
  
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS
THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY
RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/0300Z 13.7N  75.1W    35 KT
 12HR VT     03/1200Z 14.0N  75.9W    40 KT
 24HR VT     04/0000Z 14.4N  76.5W    50 KT
 36HR VT     04/1200Z 15.0N  76.6W    60 KT
 48HR VT     05/0000Z 16.0N  76.0W    70 KT
 72HR VT     06/0000Z 19.0N  73.9W    80 KT
 96HR VT     07/0000Z 22.0N  71.5W    70 KT
120HR VT     08/0000Z 22.5N  69.5W    60 KT
 
$$
FORECASTER BLAKE
 

WTNT41 KNHC 030840
TCDAT1
TROPICAL DEPRESSION TOMAS DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM EDT WED NOV 03 2010
 
AN AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS A COUPLE
OF HOURS AGO FOUND AN ILL-DEFINED AND ELONGATED CIRCULATION WITH NO
TROPICAL STORM FORCE WINDS AT EITHER THE 925 MB FLIGHT LEVEL OR THE
SURFACE.  BASED ON THIS INFORMATION...TOMAS IS BEING DOWNGRADED TO
A TROPICAL DEPRESSION AT THIS TIME.   THE PERIPHERAL CLOUD PATTERN
CONTINUES TO SHOW ORGANIZATION WITH FRAGMENTED OUTER BANDS...BUT
THERE IS LITTLE CONVECTIVE ORGANIZATION NEAR THE ESTIMATED CENTER. 
THE WEAKENING OVER THE PAST 24 HOURS IS DIFFICULT TO EXPLAIN. 
PRECIPITABLE WATER ANALYSES FROM THE UW/CIMSS DO NOT SUGGEST MUCH
OF AN INTRUSION OF DRY AIR INTO THE CIRCULATION.  THE CIRRUS
MOTIONS FROM SATELLITE IMAGES SHOW A FAIRLY WELL-DEFINED OUTFLOW
PATTERN...ESPECIALLY OVER THE NORTHERN SEMICIRCLE.  THIS WOULD
NORMALLY BE CONSISTENT WITH LIGHT VERTICAL SHEAR.  AMSU
AREA-AVERAGED WIND SHEAR DERIVED BY CSU/CIRA...HOWEVER...INDICATE A
RECENT INCREASE IN MID- TO UPPER-LEVEL SHEAR OVER TOMAS.  THIS IS
EXPECTED TO BE TEMPORARY AS GLOBAL MODELS PREDICT DECREASING SHEAR
OVER THE NEXT COUPLE OF DAYS.  THE INTENSITY FORECAST CONTINUES TO
CALL FOR TOMAS TO RESTRENGTHEN INTO A HURRICANE BEFORE REACHING
LAND.  GIVEN THE ERRATIC BEHAVIOR OF THIS TROPICAL CYCLONE THUS
FAR...THIS IS A LOW-CONFIDENCE INTENSITY FORECAST.  THE NOAA G-IV
JET IS CURRENTLY CONDUCTING A SYNOPTIC SURVEILLANCE MISSION AROUND
TOMAS WHICH SHOULD GIVE A BETTER ASSESSMENT OF THE DYNAMIC AND
THERMODYNAMIC ENVIRONMENT.

THE HURRICANE HUNTERS FOUND A BROAD AREA OF LIGHT WINDS SURROUNDING
THE LOCATION OF THE MINIMUM PRESSURE...SO THERE IS SIGNIFICANT
UNCERTAINTY IN THE CENTER POSITION AND INITIAL MOTION.  OUR BEST
GUESS AT THE LATTER IS 285/4.  THE TRACK FORECAST IS BASICALLY
UNCHANGED FROM THE PREVIOUS ADVISORY.  TOMAS IS EXPECTED TO TURN
NORTHWARD AND NORTHEASTWARD OVER THE NEXT FEW DAYS IN RESPONSE TO
THE STEERING FLOW AHEAD OF AN APPROACHING MID-TROPOSPHERIC TROUGH. 
BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS SHOW THIS TROUGH
LIFTING OUT AND LEAVING TOMAS BEHIND OVER THE SUBTROPICS FOR A FEW
DAYS.  ACCORDINGLY...THE OFFICIAL TRACK FORECAST SHOWS A TURN TO
THE RIGHT WITH DECREASING FORWARD SPEED BY DAY 5.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING...AND POTENTIAL MUD SLIDES OVER HAITI AND THE
DOMINICAN REPUBLIC LATER IN THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/0900Z 13.5N  75.5W    30 KT
 12HR VT     03/1800Z 13.8N  76.1W    35 KT
 24HR VT     04/0600Z 14.4N  76.5W    40 KT
 36HR VT     04/1800Z 15.3N  76.3W    50 KT
 48HR VT     05/0600Z 16.8N  75.3W    65 KT
 72HR VT     06/0600Z 20.0N  73.0W    65 KT
 96HR VT     07/0600Z 21.5N  71.5W    60 KT
120HR VT     08/0600Z 22.0N  69.5W    50 KT
 
$$
FORECASTER PASCH/ROBERTS
 

WTNT41 KNHC 031449
TCDAT1
TROPICAL DEPRESSION TOMAS DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT WED NOV 03 2010
 
TOMAS IS STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING.
SATELLITE IMAGERY...SURFACE OBSERVATIONS...AND DATA FROM THE NOAA
G-IV JET INDICATE THE CYCLONE HAS BECOME PART OF AN ELONGATED AREA
OF LOW PRESSURE THAT INCLUDES AN AREA OF DISTURBED WEATHER JUST
NORTH OF PANAMA.  AS A RESULT...THE CIRCULATION OF TOMAS HAS BEEN
LOSING DEFINITION.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
WILL INVESTIGATE THE SYSTEM THIS AFTERNOON TO DETERMINE WHETHER
TOMAS STILL HAS ENOUGH CIRCULATION TO BE CONSIDERED A TROPICAL
CYCLONE.  SATELLITE IMAGERY SHOWS THAT A LARGE CONVECTIVE CLUSTER
TO THE EAST OF THE CENTER...AND BASED ON THIS AND THE AIRCRAFT DATA
THE INITIAL INTENSITY REMAINS 30 KT.
 
THE INITIAL MOTION IS AN UNCERTAIN 295/5.  THERE IS LITTLE CHANGE IN
THE FORECAST TRACK OR FORECAST PHILOSOPHY FOR THE FIRST 72 -96 HR
OF THE FORECAST.  A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT
MOVING THROUGH THE GULF OF MEXICO AND THE SOUTHEASTERN UNITED
STATES SHOULD CAUSE TOMAS TO RECURVE TOWARD THE NORTHEAST DURING
THE NEXT 48 HR...WITH A GENERALLY NORTHEASTWARD MOTION CONTINUING
THROUGH 72-96 HR.  AFTER THAT TIME...THE GUIDANCE BECOMES
DIVERGENT.  THE GFDL STALLS THE CYCLONE JUST WEST OF HAITI.  THE
UKMET AND NOGAPS FORECAST TOMAS TO SHEAR OFF WITH THE REMNANT
LOW-LEVEL CIRCULATION MOVING SOUTHWESTWARD.  FINALLY...THE GFS AND
ECMWF CALL FOR A CONTINUED EASTWARD TO EAST-NORTHEASTWARD MOTION. 
THE NEW TRACK FORECAST SHOWS A SLOW EAST-NORTHEASTWARD MOTION FROM
96-120 HR AS A COMPROMISE BETWEEN THESE EXTREMES.  OVERALL...THE
FORECAST IS SIMILAR TO BUT FASTER THAN THE PREVIOUS FORECAST.
 
THE INTENSITY FORECAST IS PROBLEMATIC.  FIRST...THE CYCLONE NEEDS TO
SURVIVE ITS CURRENT STATE OF DISORGANIZATION.  IF THAT OCCURS...
LIGHT VERTICAL WIND SHEAR AND WARM SEA SURFACE TEMPERATURES APPEAR
FAVORABLE FOR STRENGTHENING FOR THE NEXT 48-72 HR OR SO IF THE
LOW-LEVEL CIRCULATION CAN CONSOLIDATE.  THE INTENSITY FORECAST
ASSUMES BOTH OF THESE THINGS WILL HAPPEN...AND THUS CALLS FOR SLOW
STRENGTHENING DURING THIS TIME.  WHILE THE GFDL AND SHIPS MODELS
STILL CALL FOR TOMAS TO REGAIN HURRICANE STRENGTH...THE NEW
INTENSITY FORECAST WILL NOT FOLLOW THIS SCENARIO DUE TO CURRENT
TRENDS AND THE LIKELIHOOD OF LAND INTERACTION WITH HISPANIOLA LATER
IN THE FORECAST PERIOD.  THE INTENSITY FORECAST IS CLOSE TO BUT
SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS MODEL ICON.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING... AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN
REPUBLIC LATER IN THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/1500Z 14.1N  75.9W    30 KT
 12HR VT     04/0000Z 14.5N  76.2W    30 KT
 24HR VT     04/1200Z 15.5N  76.2W    35 KT
 36HR VT     05/0000Z 16.8N  75.7W    45 KT
 48HR VT     05/1200Z 18.1N  74.7W    55 KT
 72HR VT     06/1200Z 21.0N  72.5W    60 KT
 96HR VT     07/1200Z 23.0N  71.0W    60 KT
120HR VT     08/1200Z 23.5N  69.0W    55 KT
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 032057
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM EDT WED NOV 03 2010

AFTER STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING...TOMAS HAS
RE-ORGANIZED DURING THE AFTERNOON.  AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT HAS FOUND A BETTER-DEFINED CIRCULATION THAN WAS
PRESENT DURING THE PREVIOUS AIRCRAFT MISSION...ALTHOUGH THE LIGHT
AND VARIABLE WIND CENTER IS STILL RATHER LARGE.  THE PLANE FOUND
FLIGHT-LEVEL WINDS OF 48 KT BELOW 1500 FT AND ESTIMATED SURFACE
WINDS NEAR 40 KT FROM THE SFMR ABOUT 45 N MI EAST OF THE MEAN
CENTER.  THE MINIMUM CENTRAL PRESSURE WAS 1003 MB.  BASED ON THESE
DATA...TOMAS IS UPGRADED TO A 40-KT TROPICAL STORM.

WITH THE RE-FORMATION OF THE CENTER TO THE EAST OF THE PREVIOUS
ADVISORY POSITION...THE INITIAL MOTION IS NOW AN UNCERTAIN 335/5. 
A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT MOVING THROUGH THE
GULF OF MEXICO AND THE SOUTHEASTERN UNITED STATES SHOULD CAUSE
TOMAS TO RECURVE TOWARD THE NORTHEAST DURING THE NEXT 48 HR...WITH
A GENERALLY NORTHEASTWARD MOTION CONTINUING THROUGH 72-96 HR. 
THERE HAS BEEN A SIGNIFICANT CHANGE IN THE TRACK GUIDANCE SINCE THE
PREVIOUS ADVISORY...WITH THE LATEST MODEL RUNS IN GOOD AGREEMENT ON
A FASTER MOTION IN THE FIRST 72-96 HR.  INDEED THE NOGAPS...WHICH
PREVIOUSLY CALLED FOR TOMAS TO SHEAR APART AND TURN SOUTHWEST...
NOW CALLS FOR THE STORM TO MOVE STEADILY NORTHEASTWARD THROUGH THE
FORECAST PERIOD.  BASED ON THIS...THE NEW FORECAST TRACK IS FASTER
THAN THE PREVIOUS TRACK THROUGH 96 HR.  AFTER THAT TIME...THE
GUIDANCE REMAINS VERY DIVERGENT.  THE UKMET CONTINUES TO FORECAST
TOMAS TO SHEAR APART WITH THE LOW-LEVEL CIRCULATION MOVING
SOUTHWESTWARD...WHILE THE CANADIAN FORECAST TOMAS OR ITS
EXTRATROPICAL REMNANTS TO REACH NEWFOUNDLAND BY 120 HR.  THE OTHER
MODELS ARE IN BETWEEN THESE RATHER DRASTIC EXTREMES.  THE INTENSITY
FORECAST WILL FOLLOW THE SCENARIO OF THE PREVIOUS ADVISORY OF A
SLOW EASTWARD MOTION AFTER 96 HR AT A HIGHER LATITUDE THAN
PREVIOUSLY FORECAST.

NOW THAT TOMAS IS CONSOLIDATING...LIGHT VERTICAL WIND SHEAR AND WARM
SEA SURFACE TEMPERATURES FAVOR INTENSIFICATION.  THE SHIPS RAPID
INTENSIFICATION INDEX SHOWS A 50 PERCENT CHANCE OF 30 KT OF
STRENGTHENING DURING THE NEXT 24 HR...ALTHOUGH THE CURRENT
ORGANIZATION OF TOMAS ARGUES AGAINST THAT MUCH INTENSIFICATION. 
THE NEW INTENSITY FORECAST IS A COMPROMISE BETWEEN THE SHIPS AND
LGEM MODELS FOR THE FIRST 36-48 HR...CALLING FOR TOMAS TO
STRENGTHEN UNTIL LAND INTERACTION WITH HISPANIOLA BEGINS.  IT IS
NOT OUT OF THE QUESTION THAT TOMAS COULD BECOME A HURRICANE BEFORE
REACHING LAND AS FORECAST BY THE SHIPS AND GFDL MODELS.  AFTER
PASSING HISPANIOLA...INCREASING SOUTHWESTERLY WIND SHEAR IS
EXPECTED TO CAUSE TOMAS TO WEAKEN.  THE NEW INTENSITY FORECAST IS
AGAIN CLOSE TO BUT SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS
MODEL ICON.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING...AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN
REPUBLIC DURING THE NEXT FEW DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/2100Z 14.9N  74.8W    40 KT
 12HR VT     04/0600Z 15.8N  75.0W    45 KT
 24HR VT     04/1800Z 16.9N  75.0W    50 KT
 36HR VT     05/0600Z 18.4N  74.5W    55 KT
 48HR VT     05/1800Z 20.2N  73.2W    60 KT
 72HR VT     06/1800Z 23.5N  71.0W    60 KT
 96HR VT     07/1800Z 26.0N  69.0W    55 KT
120HR VT     08/1800Z 26.0N  67.0W    45 KT
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 040249
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT WED NOV 03 2010
 
DATA FROM NOAA AND AIR FORCE RESERVE HURRICANE HUNTER MISSIONS
INDICATE THAT THE LOW-LEVEL CENTER OF TOMAS IS STILL NOT QUITE
ALIGNED WITH THE MID-LEVEL CENTER.  THEY HAVE MOVED CLOSER TOGETHER
DURING THE DAY...HOWEVER...AND A 2219 UTC SSMI/S MICROWAVE PASS
SHOWS CONSIDERABLY MORE BANDING THAN THIS SYSTEM HAS HAD DURING THE
PAST FEW DAYS. THE INITIAL WIND SPEED WILL REMAIN 40 KT...WHICH IS
NEAR THE FLIGHT-LEVEL AND SFMR MAXIMA REPORTED BY NOAA.
 
THE LARGE-SCALE ENVIRONMENT IS FAVORABLE FOR STRENGTHENING OF TOMAS
WITH LIGHT SOUTHWESTERLY SHEAR AND WARM WATERS.  IN FACT...ALL OF
THE RELIABLE MODELS THAT DO NOT MOVE TOMAS OVER A SIGNIFICANT
PORTION OF HAITI MAKE THE CYCLONE A HURRICANE WITHIN 36-48 HOURS. 
THE SHIPS RAPID INTENSIFICATION INDEX ALSO SHOWS A 62 PERCENT
CHANCE OF A 30-KT INCREASE WITHIN THE NEXT 24 HOURS...THOUGH THIS
MODEL WAS TOO HIGH YESTERDAY.  THIS SYSTEM HAS BURNED US BEFORE BY
DOING THE EXACT OPPOSITE OF THE GUIDANCE...BUT GIVEN THE IMPROVED
MICROWAVE PRESENTATION...I AM INCLINED TO RAISE THE FORECAST A
LITTLE BIT TO HURRICANE STATUS.  THE NEW FORECAST IS NEAR OR
SLIGHTLY BELOW A COMPOSITE OF THE GFDL...SHIPS...AND LGEM MODELS. 
WEAKENING IS FORECAST AT THE END OF THE PERIOD AS THE TROPICAL
CYCLONE INTERACTS WITH A COLD FRONT AND VERTICAL WIND SHEAR
INCREASES.
 
THE CURRENT MOTION REMAINS 330/5...THOUGH THIS IS MORE UNCERTAIN
THAN NORMAL WITH THE NHC INITIAL POSITION ON THE NORTHEASTERN SIDE
OF THE BROAD LOW-LEVEL CIRCULATION.  A WEAK RIDGE TO THE EAST OF
TOMAS IS STEERING THE STORM FOR NOW...BUT A RATHER STRONG DEEP
LAYER LOW OVER THE GULF OF MEXICO IS EXPECTED TO CAUSE THE TROPICAL
CYCLONE TO TURN TOWARD THE NORTH TOMORROW...AND THE NORTH-NORTHEAST
BY EARLY FRIDAY.  TOMAS SHOULD BE ACCELERATING AS IT PASSES NEAR
HAITI AS THE MID-LATITUDE LOW APPROACHES.  ONLY COSMETIC CHANGES
WERE MADE TO THE NHC FORECAST WITH THE MOST RELIABLE MODELS STILL
FOCUSED ON A TRACK TOWARD SOUTHWESTERN HAITI.  AT DAYS 4 AND
5...THERE ARE SOME INDICATIONS FROM THE MODELS THAT THE GULF OF
MEXICO LOW WILL LEAVE TOMAS BEHIND TO THE EAST OF THE BAHAMAS...AND
THE OFFICIAL FORECAST IS SHIFTED TO THE RIGHT AT THAT TIME.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING...AND LIFE-THREATENING MUD SLIDES OVER HAITI AND THE
DOMINICAN REPUBLIC DURING THE NEXT FEW DAYS.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0300Z 15.4N  75.2W    40 KT
 12HR VT     04/1200Z 16.1N  75.4W    45 KT
 24HR VT     05/0000Z 17.4N  75.0W    55 KT
 36HR VT     05/1200Z 19.1N  74.0W    65 KT
 48HR VT     06/0000Z 21.0N  72.5W    65 KT
 72HR VT     07/0000Z 24.0N  70.5W    65 KT
 96HR VT     08/0000Z 25.0N  68.5W    55 KT
120HR VT     09/0000Z 25.0N  66.5W    45 KT
 
$$
FORECASTER BLAKE
 

WTNT41 KNHC 040841
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM EDT THU NOV 04 2010
 
SATELLITE PICTURES SUGGEST THAT THE CLOUD PATTERN OF TOMAS HAS NOT
CHANGED SIGNIFICANTLY DURING THE LAST SEVERAL HOURS.  HOWEVER...
DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT THE PRESSURE HAS FALLEN TO 997 MB WITH MAXIMUM SURFACE WINDS
OF 41 KT.  DESPITE THE AIRCRAFT DATA WHICH ARE INDICATIVE OF SLIGHT
STRENGTHENING...THE VORTEX HAS BEEN TILTED IN THE VERTICAL BASED
UPON  COMPARISON OF EARLIER NOAA AND AIR FORCE AIRCRAFT DATA.
GIVEN THE SIGNIFICANTLY LOWER CENTRAL PRESSURE FROM THE AIRCRAFT...
THE INITIAL INTENSITY IS INCREASED TO 45 KT FOR THIS ADVISORY.
 
THE CURRENT MOTION ESTIMATE REMAINS 330/06.  THE FORECAST PHILOSOPHY
REGARDING THE TRACK OF TOMAS IS UNCHANGED.  TOMAS SHOULD BE STEERED
NORTH-NORTHWESTWARD TO NORTHWARD AROUND A LOW- TO MID-LEVEL RIDGE
LOCATED OVER THE WEST CENTRAL ATLANTIC TODAY.  AFTER THAT...TOMAS
SHOULD BEGIN TO ENCOUNTER AN INCREASING SOUTHWESTERLY FLOW
ASSOCIATED WITH AN ANOMALOUSLY DEEP MID- TO UPPER-LEVEL TROUGH
MOVING ACROSS EASTERN NORTH AMERICA AND TURN NORTHEASTWARD WHILE
ACCELERATING.  EVEN THOUGH THE SYNOPTIC REASONING HAS NOT CHANGED
FROM THE PREVIOUS PACKAGE...THE OFFICIAL FORECAST TRACK IS SHIFTED
TO THE LEFT ON ACCOUNT OF THE MOST RECENT AIRCRAFT CENTER FIXES.
 
ALTHOUGH LARGE-SCALE FACTORS OF MODERATELY LOW SHEAR AND WARM WATERS
ARE FAVORABLE FOR FURTHER INTENSIFICATION OF TOMAS...THE VERTICAL
TILT OF THE VORTEX AND THE BROAD NATURE OF THE CIRCULATION MAY
ARGUE AGAINST A RAPID INCREASE IN STRENGTH.  INTERESTINGLY...THE
SHIPS RAPID INTENSIFICATION INDEX THAT HAD BEEN SHOWING THE
POTENTIAL FOR A 30-KT INCREASE WITHIN THE NEXT 24 HOURS IS NOT AS
HIGH AS IT WAS BEFORE.  THE NEW NHC FORECAST IS SIMILAR TO THE
PREVIOUS ONE AND ASSUMES THAT THE LARGE-SCALE ENVIRONMENT SHOULD BE
CONDUCIVE ENOUGH TO ALLOW FOR STENGTHENING DURING THE NEXT 24-36
HOURS.  BEYOND 36 HOURS...STRONG AND INCREASING SOUTHWESTERLY SHEAR
OVER THE WESTERN ATLANTIC IS FORECAST TO CAUSE WEAKENING...PERHAPS
AT A MORE RAPID PACE THAN INDICATED IN THE CURRENT FORECAST.  THE
NEW NHC FORECAST IS REDUCED FROM THE PREVIOUS ONE AT LATER FORECAST
TIMES GIVEN THE STRONG FORECAST SHEAR.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL...
WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES
OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF
DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0900Z 15.8N  76.1W    45 KT
 12HR VT     04/1800Z 17.0N  76.0W    55 KT
 24HR VT     05/0600Z 18.8N  75.0W    65 KT
 36HR VT     05/1800Z 21.0N  73.4W    65 KT
 48HR VT     06/0600Z 23.5N  71.5W    55 KT
 72HR VT     07/0600Z 26.0N  69.5W    45 KT
 96HR VT     08/0600Z 28.0N  67.0W    35 KT
120HR VT     09/0600Z 28.0N  65.0W    25 KT
 
$$
FORECASTER KIMBERLAIN/PASCH
 

WTNT41 KNHC 041504
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT THU NOV 04 2010
 
SATELLITE IMAGERY...ALONG WITH REPORTS FROM AIR FORCE RESERVE AND
NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE CENTER OF TOMAS IS
LOCATED NEAR THE WESTERN EDGE OF THE MAIN CONVECTIVE MASS.  THE
NOAA PLANE HAS MEASURED 700 MB FLIGHT-LEVEL WINDS OF 44 KT...AND A
RECENT DROPSONDE SUGGESTS SURFACE WINDS AROUND 40 KT AND A CENTRAL
PRESSURE BELOW 997 MB.  BASED ON THESE DATA...THE INITIAL INTENSITY
REMAINS 40 KT.  THE CIRRUS OUTFLOW IS CURRENTLY GOOD OVER THE
NORTHEASTERN SEMICIRCLE AND POOR ELSEWHERE.

THE INITIAL MOTION IS NOW A SOMEWHAT UNCERTAIN 350/7.  A LARGE
DEEP-LAYER TROUGH AND ASSOCIATED COLD FRONT SHOULD CAUSE TOMAS TO
MOVE NORTHWARD TO NORTHEASTWARD FOR THE NEXT 48 HR OR SO...WITH THE
CENTER PASSING NEAR OR OVER JAMAICA...HAITI...EASTERN CUBA...AND
THE SOUTHEASTERN BAHAMAS.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT
WITH THIS SCENARIO...AND THIS PART OF THE FORECAST TRACK IS AN
UPDATE OF THE PREVIOUS TRACK.  AFTER 48 HR...THE GUIDANCE IS
DIVERGENT AND INCONSISTENT.  THE ECMWF SHOWS TOMAS MOVING ALONG THE
SOUTHERN PERIPHERY OF THE DEEP-LAYER TROUGH...AND THIS IS
CONSISTENT WITH ITS PREVIOUS RUN.  THE GFS...GFDL...AND HWRF NOW
CALL FOR TOMAS TO MOVE RAPIDLY NORTHWARD AND BE ABSORBED INTO THE
TROUGH...WHICH IS A MAJOR CHANGE FROM THE 6 HOUR OLD RUNS.  ON THE
OTHER HAND...THE NOGAPS...WHICH 6 HR AGO WAS CALLING FOR A
CONTINUED NORTHWARD MOTION...NOW CALLS FOR AN EASTWARD TURN SIMILAR
TO THE ECMWF.  OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED
NORTHWARD FROM THE PREVIOUS ADVISORY.  THE 72-120 HR PORTION OF THE
TRACK WILL ALSO BE SHIFTED NORTHWARD...BUT IS WELL SOUTH OF THE
CONSENSUS MODELS AND THE CENTER OF THE GUIDANCE ENVELOPE.  THIS
PART OF THE FORECAST TRACK IS LOW CONFIDENCE.

TOMAS IS EXPERIENCING 10-15 KT OF SOUTH-SOUTHWESTERLY VERTICAL WIND
SHEAR...AND THE CYCLONE SHOULD REMAIN IN A LIGHT/MODERATE SHEAR
ENVIRONMENT FOR THE NEXT 36-48 HR.  THIS SHOULD ALLOW STRENGTHENING
AS LONG AS THE CENTER REMAINS OVER WATER.  THIS PART OF THE NEW
INTENSITY FORECAST IS ONLY SLIGHTLY CHANGED FROM THE PREVIOUS
ADVISORY AND IS CLOSEST TO THE SHIPS MODEL.  AFTER 48 HR...THE
INTENSITY AND EVENTUAL FATE OF TOMAS ARE STRONGLY TIED TO ITS
TRACK.  A NORTHWARD TRACK WOULD RESULT IN A RAPID EXTRATROPICAL
TRANSITION AND ABSORPTION BY THE DEEP-LAYER TROUGH.  AN EASTWARD
TRACK WOULD KEEP THE SYSTEM NEAR OR JUST AHEAD OF THE COLD FRONT IN
AN AREA OF STRONG WIND SHEAR.  EITHER WAY...TOMAS SHOULD WEAKEN
DURING THIS TIME AND THIS IS REFLECTED IN THE INTENSITY FORECAST. 
THE 120 HR FORECAST NOW CALLS FOR EXTRATROPICAL TRANSITION...AND
THIS COULD OCCUR EARLIER IF THE CYCLONE MOVES FARTHER NORTH THAN
FORECAST.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL...
WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES
OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF
DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/1500Z 16.3N  76.1W    40 KT
 12HR VT     05/0000Z 17.5N  75.9W    50 KT
 24HR VT     05/1200Z 19.5N  74.7W    60 KT
 36HR VT     06/0000Z 21.8N  73.1W    65 KT
 48HR VT     06/1200Z 24.3N  71.3W    55 KT
 72HR VT     07/1200Z 28.0N  69.0W    40 KT
 96HR VT     08/1200Z 29.5N  66.5W    30 KT
120HR VT     09/1200Z 29.5N  63.5W    30 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 041537
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  26...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT THU NOV 04 2010

CORRECTED INITIAL INTENSITY TO 45 KT
 
SATELLITE IMAGERY...ALONG WITH REPORTS FROM AIR FORCE RESERVE AND
NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE CENTER OF TOMAS IS
LOCATED NEAR THE WESTERN EDGE OF THE MAIN CONVECTIVE MASS.  THE
NOAA PLANE HAS MEASURED 700 MB FLIGHT-LEVEL WINDS OF 44 KT...AND A
RECENT DROPSONDE SUGGESTS SURFACE WINDS AROUND 40-45 KT AND A
CENTRAL PRESSURE BELOW 997 MB.  BASED ON THESE DATA...THE INITIAL
INTENSITY REMAINS 45 KT.  THE CIRRUS OUTFLOW IS CURRENTLY GOOD OVER
THE NORTHEASTERN SEMICIRCLE AND POOR ELSEWHERE.
 
THE INITIAL MOTION IS NOW A SOMEWHAT UNCERTAIN 350/7.  A LARGE
DEEP-LAYER TROUGH AND ASSOCIATED COLD FRONT SHOULD CAUSE TOMAS TO
MOVE NORTHWARD TO NORTHEASTWARD FOR THE NEXT 48 HR OR SO...WITH THE
CENTER PASSING NEAR OR OVER JAMAICA...HAITI...EASTERN CUBA...AND
THE SOUTHEASTERN BAHAMAS.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT
WITH THIS SCENARIO...AND THIS PART OF THE FORECAST TRACK IS AN
UPDATE OF THE PREVIOUS TRACK.  AFTER 48 HR...THE GUIDANCE IS
DIVERGENT AND INCONSISTENT.  THE ECMWF SHOWS TOMAS MOVING ALONG THE
SOUTHERN PERIPHERY OF THE DEEP-LAYER TROUGH...AND THIS IS
CONSISTENT WITH ITS PREVIOUS RUN.  THE GFS...GFDL...AND HWRF NOW
CALL FOR TOMAS TO MOVE RAPIDLY NORTHWARD AND BE ABSORBED INTO THE
TROUGH...WHICH IS A MAJOR CHANGE FROM THE 6 HOUR OLD RUNS.  ON THE
OTHER HAND...THE NOGAPS...WHICH 6 HR AGO WAS CALLING FOR A
CONTINUED NORTHWARD MOTION...NOW CALLS FOR AN EASTWARD TURN SIMILAR
TO THE ECMWF.  OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED
NORTHWARD FROM THE PREVIOUS ADVISORY.  THE 72-120 HR PORTION OF THE
TRACK WILL ALSO BE SHIFTED NORTHWARD...BUT IS WELL SOUTH OF THE
CONSENSUS MODELS AND THE CENTER OF THE GUIDANCE ENVELOPE.  THIS
PART OF THE FORECAST TRACK IS LOW CONFIDENCE.
 
TOMAS IS EXPERIENCING 10-15 KT OF SOUTH-SOUTHWESTERLY VERTICAL WIND
SHEAR...AND THE CYCLONE SHOULD REMAIN IN A LIGHT/MODERATE SHEAR
ENVIRONMENT FOR THE NEXT 36-48 HR.  THIS SHOULD ALLOW STRENGTHENING
AS LONG AS THE CENTER REMAINS OVER WATER.  THIS PART OF THE NEW
INTENSITY FORECAST IS ONLY SLIGHTLY CHANGED FROM THE PREVIOUS
ADVISORY AND IS CLOSEST TO THE SHIPS MODEL.  AFTER 48 HR...THE
INTENSITY AND EVENTUAL FATE OF TOMAS ARE STRONGLY TIED TO ITS
TRACK.  A NORTHWARD TRACK WOULD RESULT IN A RAPID EXTRATROPICAL
TRANSITION AND ABSORPTION BY THE DEEP-LAYER TROUGH.  AN EASTWARD
TRACK WOULD KEEP THE SYSTEM NEAR OR JUST AHEAD OF THE COLD FRONT IN
AN AREA OF STRONG WIND SHEAR.  EITHER WAY...TOMAS SHOULD WEAKEN
DURING THIS TIME AND THIS IS REFLECTED IN THE INTENSITY FORECAST.
THE 120 HR FORECAST NOW CALLS FOR EXTRATROPICAL TRANSITION...AND
THIS COULD OCCUR EARLIER IF THE CYCLONE MOVES FARTHER NORTH THAN
FORECAST.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL...
WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES
OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF
DAYS.
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/1500Z 16.3N  76.1W    45 KT
 12HR VT     05/0000Z 17.5N  75.9W    50 KT
 24HR VT     05/1200Z 19.5N  74.7W    60 KT
 36HR VT     06/0000Z 21.8N  73.1W    65 KT
 48HR VT     06/1200Z 24.3N  71.3W    55 KT
 72HR VT     07/1200Z 28.0N  69.0W    40 KT
 96HR VT     08/1200Z 29.5N  66.5W    30 KT
120HR VT     09/1200Z 29.5N  63.5W    30 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 042056
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM EDT THU NOV 04 2010
 
THIS AFTERNOON...TOMAS CONTINUES AS A SHEARED TROPICAL STORM WITH
MOST OF THE DEEP CONVECTION LOCATED EAST OF A LOW-LEVEL SWIRL.
DESPITE APPEARANCES THAT THE SWIRL IS THE CIRCULATION CENTER...THE
AIR FORCE C-130 OBSERVATIONS INDICATE THAT THIS FEATURE HAS BEEN
ROTATING AROUND A BROADER MEAN CENTER.  THE RECONNAISSANCE ALSO
OBSERVED A CENTRAL PRESSURE OF 995 MB AND EQUIVALENT WINDS AT THE
SURFACE OF ABOUT 45 KT...THOUGH THIS WIND VALUE COULD BE SLIGHTLY
GENEROUS.
 
THE MOTION OF THE CYCLONE IS 350 DEGREES AT 4 KT AS IT IS PRIMARILY
BEING STEERED TO THE NORTH AROUND THE WESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE.  A VIGOROUS SHORT-WAVE TROUGH CURRENTLY OVER THE
GULF OF MEXICO SHOULD INDUCE RECURVATURE OF TOMAS TOWARD THE
NORTH-NORTHEAST AND ACCELERATION OF ITS FORWARD SPEED DURING THE 36
HR OR SO.  THE TRACK MODELS ARE IN EXCELLENT AGREEMENT ON THIS
POINT AND THE OFFICIAL FORECAST THROUGH 36 HR IS CLOSE TO THE MODEL
CONSENSUS AND THE PREVIOUS ADVISORY.  AT 48 HR AND
BEYOND...HOWEVER...THE EVENTUAL TRACK OF TOMAS IS QUITE UNCERTAIN.
ONE GROUP OF MODELS...INCLUDING THE GFS...GFS ENSEMBLE
MEAN...NOGAPS...HWRF...AND GFDL...CONTINUE TO SPEED THE CYCLONE
NORTH-NORTHEASTWARD AND HAVE IT BECOMING EXTRATROPICAL AS IT
ENCOUNTERS A STRONG COLD FRONT.  ANOTHER SCENARIO...SHARED BY THE
ECMWF AND UKMET MODELS...IS THAT THE CYCLONE WOULD BECOME SHEARED
AND SHALLOW...NOT PICKED UP BY THE TROUGH AND FRONT...AND MEANDER
EASTWARD FOR A COUPLE DAYS.  THE CONSENSUS TECHNIQUES...BY
DESIGN...SPLIT THE DIFFERENCE...WHICH IS NOT VERY LIKELY TO BE
CORRECT.  IN A SOMEWHAT UNCOMFORTABLE COMPROMISE...THIS TRACK
FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS ADVISORY BUT IS
SOMEWHAT EQUATORWARD OF THE MODEL CONSENSUS.
 
TOMAS HAS ABOUT A DAY OR TWO TO INTENSIFY UNDER THE INFLUENCE OF
MODERATE SOUTHERLY VERTICAL SHEAR...A MOIST ENVIRONMENT...VERY WARM
WATERS...AND A SOMEWHAT UNSTABLE ATMOSPHERE.  BEYOND TWO DAYS...THE
CYCLONE SHOULD EXPERIENCE STRONG WESTERLY SHEAR AND INCREASINGLY
COOLER WATERS.  THE INTENSITY PREDICTION IS QUITE CLOSE TO A
CONSENSUS OF DECAY-SHIPS...LGEM...AND GFDL MODELS AND NEARLY THE
SAME AS THE PREVIOUS ADVISORY.  IT SHOULD BE NOTED THAT IF THE
TRACK DOES TAKE THE CYCLONE DIRECTLY OVER EITHER EASTERN CUBA OR
HISPANIOLA FOR MORE THAN A FEW HOURS...THE CYCLONE WOULD BE WEAKER
THAN INDICATED HERE.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL...
WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES
OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF
DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/2100Z 16.6N  76.0W    45 KT
 12HR VT     05/0600Z 17.8N  75.6W    50 KT
 24HR VT     05/1800Z 20.1N  74.3W    60 KT
 36HR VT     06/0600Z 22.6N  72.5W    65 KT
 48HR VT     06/1800Z 24.8N  71.1W    55 KT
 72HR VT     07/1800Z 27.5N  69.0W    40 KT
 96HR VT     08/1800Z 28.5N  66.5W    30 KT
120HR VT     09/1800Z 29.0N  64.5W    30 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER LANDSEA/BEVEN
 

WTNT41 KNHC 050244
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT THU NOV 04 2010
 
THERE HAS BEEN A SHARP INCREASE IN THE INNER-CORE WIND STRUCTURE AND
CONVECTIVE ORGANIZATION OF TOMAS DURING THE PAST 6 HOURS. ALTHOUGH
BOTH AIR FORCE RESERVE AND NOAA HURRICANE AIRCRAFT INDICATE THERE
IS ABOUT 12 NMI NORTHEASTWARD TILT TO THE VORTEX...THIS HAS NOT
PREVENTED THE CENTRAL PRESSURE FROM FALLING AND THE WINDS FROM
INCREASING. THE MAXIMUM 850-MB FLIGHT-LEVEL WINDS REPORTED BY THE
AIR FORCE WAS 61 KT...AND 58 KT WAS REPORTED AT 700 MB BY THE NOAA
HURRICANE HUNTERS. MAXIMUM SFMR WINDS HAVE BEEN AROUND 56-58 KT.
THE LATEST NOAA RECON PRESSURE WAS DOWN TO 989 MB...AND THAT WAS
WITH 13 KT OF WIND AT THE SURFACE. A COMBINATION OF THESE DATA
EASILY SUPPORT INCREASING THE INTENSITY TO 55 KT...WHICH COULD BE A
LITTLE CONSERVATIVE GIVEN THAT A WARM SPOT HAS APPEARED
INTERMITTENTLY WITHIN A RING OF VERY COLD TOPS OF -80C TO -85C NEAR
THE CENTER.
 
THE INITIAL MOTION ESTIMATE IS NOW 030/08. TOMAS HAS NOW MOVED NORTH
OF A MID-LEVEL RIDGE THAT LIES EAST-WEST ACROSS THE CENTRAL
CARIBBEAN SEA. TOMAS SHOULD CONTINUE TO MOVE AROUND THE WESTERN
PERIPHERY OF THE RIDGE AND GRADUALLY ACCELERATE NORTHEASTWARD AS IT
COMES UNDER THE INFLUENCE OF MODERATE SOUTHWESTERLY FLOW AHEAD OF A
DEEP MID-LATITUDE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE
EASTERN U.S....FLORIDA...AND THE EASTERN GULF OF MEXICO. THE TRACK
MODELS REMAIN IN EXCELLENT AGREEMENT ON THIS DEVELOPING SCENARIO
THROUGH 48 HOURS...AND THE MODEL TRACKS HAVE EVEN SHIFTED MORE TO
THE EAST ON THE LATEST FORECAST CYCLE. HOWEVER...AFTER THAT TIME...
HOWLING WESTERLY WIND SHEAR IN EXCESS OF 60 KT IS EXPECTED TO SHEAR
APART TOMAS AND LEAVE BEHIND A REMNANT LOW PRESSURE SYSTEM THAT
SHOULD BE STEERED SLOWLY EASTWARD BY WEAKER LOW-LEVEL WESTERLY FLOW
ON THE SOUTH SIDE OF AN EXTRATROPICAL LOW PRESSURE SYSTEM. THE GFDL
AND HWRF MODELS TAKE TOMAS OR ITS REMNANTS RAPIDLY NORTHWARD AND
MERGE IT WITH A DEEP EXTRATROPICAL LOW NEAR THE NORTHEAST U.S.
COAST AND THE CANADIAN MARITIMES. HOWEVER...THE GFS...ECMWF...
UKMET...AND NOGAPS MODELS SHOW TOMAS SHEARING APART AND REMAINING
JUST NORTH OF THE GREATER ANTILLES. THE LATTER SCENARIO IS
PREFERRED GIVEN THE EXTREMELY HOSTILE SHEAR CONDITIONS THAT ARE
FORECAST TO AFFECT THE CYCLONE BY 72 HOURS AND BEYOND. THE OFFICIAL
FORECAST TRACK HAS BEEN SHIFTED A LITTLE TO THE RIGHT OF THE
PREVIOUS TRACK...BUT MAINLY TO ACCOUNT FOR THE MORE EASTERLY
INITIAL POSITION.
 
TOMAS HAS ABOUT 24 HOURS OR SO TO STRENGTHEN OVER 29C SSTS AND IN A
RELATIVELY LOW SHEAR ENVIRONMENT. HOWEVER...BY 36 HOURS...MID-LEVEL
HUMIDITIES ARE FORECAST TO DECREASE BELOW 40 PERCENT...WHICH COULD
ACT TO ERODE THE INNER-CORE CONVECTION. AS MENTIONED ABOVE...BY 48
HOURS THE VERTICAL SHEAR IS EXPECTED TO INCREASE SHARPLY AND TOMAS
SHOULD BEGIN A STEADY WEAKENING TREND. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO BUT SLIGHTLY LOWER THAN THE SHIPS...LGEM...
AND GFDL MODELS. 
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE WILL BE HEAVY
RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING
MUD SLIDES OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT
COUPLE OF DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0300Z 17.3N  75.5W    55 KT
 12HR VT     05/1200Z 18.8N  74.6W    65 KT
 24HR VT     06/0000Z 21.0N  73.1W    70 KT
 36HR VT     06/1200Z 23.4N  71.5W    70 KT
 48HR VT     07/0000Z 25.1N  70.2W    55 KT
 72HR VT     08/0000Z 27.2N  67.9W    40 KT
 96HR VT     09/0000Z 28.3N  65.8W    30 KT...POST-TROPICAL
120HR VT     10/0000Z 28.5N  64.0W    30 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 050838
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM EDT FRI NOV 05 2010

TOMAS HAS REGAINED HURRICANE STRENGTH.  THE AIR FORCE HURRICANE
HUNTERS FOUND A PEAK 850 MB FLIGHT-LEVEL WIND OF 88 KT AND MAXIMUM
SFMR-OBSERVED SURFACE WINDS OF 75 KT.  THE LATTER OBSERVATION
APPEARED TO BE SOMEWHAT OF A SPIKE IN THE RECORD...AND USING A
BLEND OF THE SURFACE AND FLIGHT-LEVEL DATA GIVES 70 KT FOR THE
CURRENT INTENSITY ESTIMATE.   OBSERVATIONS FROM THE AIRCRAFT AND A
TRMM MICROWAVE OVERPASS SUGGEST THAT THE CYCLONE IS TILTED
NORTHWARD AS A RESULT OF SOUTHERLY OR SOUTH-SOUTHWESTERLY VERTICAL
WIND SHEAR.   SATELLITE IMAGERY SHOWS A WELL-DEFINED CENTRAL DENSE
OVERCAST...WITH CLOUD TOP TEMPS APPROACHING -90C.

THE INITIAL MOTION ESTIMATE IS 035/08.  TOMAS IS LOCATED ON THE EAST
SIDE OF AN UNUSUALLY DEEP MID- TO UPPER-LEVEL TROUGH CURRENTLY
AMPLIFYING OVER THE EASTERN UNITED STATES.  THE CYCLONE SHOULD
GRADUALLY BECOME EMBEDDED IN AN INCREASING SOUTHWESTERLY WIND FLOW
AHEAD OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AND MOVE ON A
GENERAL NORTHEASTWARD COURSE WITH SOME INCREASE IN FORWARD
SPEED.  AFTER 48 HOURS...TOMAS SHOULD GRADUALLY SLOW DOWN AND TURN
EAST-NORTHEASTWARD AND THEN EASTWARD IN A WEAKER LOW-LEVEL
WESTERLY STEERING FLOW AS THE INCREASING SHEAR REDUCES TOMAS TO A
SHALLOWER FEATURE.  THIS IS THE GENERAL SCENARIO DEPICTED BY THE
GFS AND U.K. MET. OFFICE GLOBAL MODELS.  AN ALTERNATIVE EVOLUTION
IS SUGGESTED BY SOME OF THE OTHER GUIDANCE SUCH AS THE ECMWF.  THE
LATTER MODEL SHOWS A STRONGER CYCLONE NEAR THE END OF THE FORECAST
PERIOD...PRESUMABLY DUE TO BAROCLINIC FORCING...THAT MOVES MORE
QUICKLY TOWARDS THE NORTHEAST.  THE OFFICIAL NHC TRACK FORECAST IS
VIRTUALLY UNCHANGED FROM THE PREVIOUS ONE AND IS ON THE EASTERN
SIDE OF THE GUIDANCE ENVELOPE.
 
TOMAS STILL HAS ABOUT 24 HOURS OR SO TO STRENGTHEN IN AN ENVIRONMENT
OF RELATIVELY LOW SHEAR...HIGH MOISTURE...AND OVER WARM WATERS.
AFTER THAT...A RAPID INCREASE IN SOUTHWESTERLY SHEAR ASSOCIATED
WITH THE EASTERN U.S. TROUGH...NOT TO MENTION DRIER AND COOLER
ASSOCIATED WITH THE SAME FEATURE IMPINGING ON THE CIRCULATION...
SHOULD BRING ABOUT A PRONOUNCED WEAKENING PHASE.  THE NEW NHC
FORECAST IS LOWER THAN THE SHIPS/LGEM INTENSITY GUIDANCE BUT ABOUT
THE SAME AS THE PREVIOUS OFFICIAL FORECAST...INDICATING
INTENSIFICATION TO HURRICANE STRENGTH WITHIN 24 HOURS AND WEAKENING
TO A REMNANT LOW IN 96 HOURS.  WEAKENING AFTER 48 HOURS COULD BE
MORE RAPID THAN INDICATED...CONSIDERING THAT THE SHEAR COULD BE
HIGHER THAN 60 KT AFTER 60 HOURS.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE
HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-
THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN
REPUBLIC DURING THE NEXT COUPLE OF DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0900Z 18.1N  74.9W    70 KT
 12HR VT     05/1800Z 19.8N  73.9W    75 KT
 24HR VT     06/0600Z 22.1N  72.4W    75 KT
 36HR VT     06/1800Z 24.4N  70.9W    65 KT
 48HR VT     07/0600Z 25.8N  69.6W    50 KT
 72HR VT     08/0600Z 27.5N  67.5W    35 KT
 96HR VT     09/0600Z 28.5N  65.0W    25 KT...POST-TROP/REMNT LOW
120HR VT     10/0600Z 28.5N  63.0W    25 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER KIMBERLAIN/PASCH
 

WTNT41 KNHC 051505
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT FRI NOV 05 2010

BEFORE IT DEPARTED TOMAS...THE AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT REPORTED THAT THE CENTRAL PRESSURE HAD RISEN SLIGHTLY TO
987 MB.  HOWEVER...THE FLIGHT-LEVEL AND SFMR WINDS STILL SUPPORTED
AN INTENSITY OF 75 KT...WHICH IS THE INITIAL INTENSITY FOR THIS
ADVISORY.  THE CENTRAL CONVECTION IS CURRENTLY LOOKING A LITTLE
RAGGED IN SATELLITE IMAGERY AND RADAR DATA FROM CUBA...POSSIBLY DUE
TO THE CIRCULATION OF TOMAS INTERACTING WITH THE MOUNTAINS OF
HISPANIOLA.  THE CIRRUS OUTFLOW IS GOOD TO EXCELLENT OVER THE
NORTHERN SEMICIRCLE AND POOR ELSEWHERE.

THE INITIAL MOTION IS 030/10.  TOMAS IS TO THE EAST OF A STRONG
DEEP-LAYER TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM OVER THE
EASTERN UNITED STATES AND THE WESTERN ATLANTIC.  FOR THE NEXT
36-48 HR...THIS FEATURE SHOULD STEER THE HURRICANE GENERALLY
NORTH-NORTHEASTWARD.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH
THE DIRECTION OF MOTION...BUT THERE ARE DIFFERENCES IN SPEED
BETWEEN THE FASTER GFS/GFDL/HWRF AND THE SLOWER UKMET/ECMWF/NOGAPS. 
THIS PART OF THE FORECAST TRACK IS SIMILAR TO...BUT A LITTLE TO THE
LEFT OF...THE PREVIOUS TRACK...AND IN THE MIDDLE OF THE GUIDANCE
ENVELOPE.  AFTER 36-48 HR...THE GUIDANCE SHOWS SIGNIFICANT SPREAD
IN BOTH DIRECTION AND SPEED.  THE UKMET AND NOGAPS...WHICH APPEAR
TO SHEAR TOMAS APART...SHOW A SLOW EASTWARD MOTION SOUTH OF 25N. 
THE GFS/GFDL/HWRF MOVE TOMAS MUCH MORE QUICKLY TO THE NORTH OR
NORTHEAST AND ABSORB IT INTO THE BAROCLINIC SYSTEMS OVER THE
WESTERN ATLANTIC.   THE ECMWF IS IN BETWEEN...SHOWING AN EASTWARD
TURN FOLLOWED BY AN EAST-NORTHEASTWARD MOTION BY THE END OF THE
FORECAST PERIOD.  THIS PART OF THE NEW FORECAST TRACK LIES SOUTH OF
THE CENTER OF THE GUIDANCE ENVELOPE BETWEEN THE CONSENSUS MODELS
AND THE ECMWF...AND SHOWS A SLOWER FORWARD SPEED THE THE ECMWF. 
THIS PORTION OF THE TRACK FORECAST REMAINS LOW CONFIDENCE.
 
TOMAS STILL HAS ABOUT 24 HR IN WHICH TO STRENGTHEN BEFORE
ENCOUNTERING INCREASING VERTICAL WIND SHEAR AND DRIER AIR
ASSOCIATED WITH THE TROUGH...WITH THE CAVEAT THAT INTERACTION WITH
HISPANIOLA COULD SLOW OR HALT DEVELOPMENT.  THE SHIPS...LGEM...AND
GFDL MODELS NOW SHOW THE CYCLONE BECOMING A CATEGORY 2 HURRICANE IN
24 HR...AND THE NEW INTENSITY FORECAST WILL FOLLOW SUIT.  AFTER
THAT...THE CYCLONE IS EXPECTED TO ENCOUNTER HOSTILE ENOUGH
CONDITIONS TO CAUSE WEAKENING REGARDLESS OF THE EXACT TRACK IT
TAKES...AND THE FORECAST FOLLOWS THE TREND OF THE PREVIOUS ADVISORY
IN SHOWING A QUICK WEAKENING.  THE FINAL DEMISE OF TOMAS IS
DEPENDENT UPON ITS TRACK...AS A MORE NORTHWARD MOTION WOULD LIKELY
LEAD TO EXTRATROPICAL TRANSITION AND A MORE EASTWARD MOTION TO
DEGENERATION INTO A REMNANT LOW.  THE FORECAST WILL CONTINUE TO USE
THE LATTER SCENARIO FOR THE TIME BEING.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE
HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-
THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN
REPUBLIC DURING THE NEXT COUPLE OF DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/1500Z 19.1N  74.4W    75 KT
 12HR VT     06/0000Z 20.8N  73.4W    80 KT
 24HR VT     06/1200Z 23.1N  72.1W    90 KT
 36HR VT     07/0000Z 25.1N  71.0W    80 KT
 48HR VT     07/1200Z 26.0N  69.9W    65 KT
 72HR VT     08/1200Z 27.5N  67.5W    40 KT
 96HR VT     09/1200Z 28.0N  64.5W    25 KT...POST-TROP/REMNT LOW
120HR VT     10/1200Z 29.0N  62.5W    25 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 052059
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  31
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM EDT FRI NOV 05 2010
 
THE CONVECTIVE STRUCTURE OF HURRICANE TOMAS HAS BEEN DISRUPTED THIS
AFTERNOON.  WHILE SOME OF THIS DISORGANIZATION MAY HAVE BEEN DUE TO
MODERATE SOUTHERLY VERTICAL SHEAR...IT IS MORE LIKELY THAT TOMAS
HAS BEEN AFFECTED BY HAVING SOME OF ITS CIRCULATION PASS OVER THE
HIGHER TOPOGRAPHIC REGIONS OF EASTERN CUBA AND HAITI.  THE HIGHEST
FLIGHT-LEVEL WINDS REPORTED BY THE AIR FORCE HURRICANE HUNTERS IS
62 KT WITH PEAK SFMR SURFACE WINDS OF ABOUT THE SAME.  THE CURRENT
INTENSITY IS REDUCED TO 65 KT AND THIS MAY BE SLIGHTLY GENEROUS.

AS TOMAS PROGRESSES NORTHEASTWARD DURING THE NEXT DAY...IT MOVES
AWAY FROM THE GREATER ANTILLES AND HAS A BRIEF OPPORTUNITY TO
REINTENSIFY.  WHILE THE CYCLONE WILL LIKELY REMAIN OVER WARM WATERS
FOR AT LEAST THE NEXT COUPLE OF DAYS...EXPECTED VERY STRONG
VERTICAL SHEAR AND STABLE/DRY ATMOSPHERE SHOULD LEAD TO A FAIRLY
RAPID WEAKENING.  THE FORECAST INTENSITY IS BASED ON A BLEND OF THE
SHIPS/LGEM/GFDL MODELS AND IS SLIGHTLY LOWERED FROM THE PREVIOUS
ADVISORY.  ALTERNATIVELY...IF THE INNER CORE OF TOMAS DOES NOT
QUICKLY REORGANIZE...THE SYSTEM MAY SIMPLY CONTINUE TO WEAKEN FROM
HERE ON IN.  WHILE THE FORECAST HERE CALLS FOR THE CYCLONE TO
BECOME A REMNANT LOW AT DAY 4...IT IS QUITE POSSIBLE THAT INSTEAD
THE SYSTEM COULD EVOLVE INTO AN EXTRATROPICAL LOW AFTER INTERACTING
WITH THE STRONG APPROACHING COLD FRONT.

THE HURRICANE IS CURRENTLY MOVING AT 35/12...PRIMARILY DUE TO THE
INFLUENCE OF COMBINED INFLUENCE OF A NORTH-SOUTH ORIENTED RIDGE TO
ITS EAST AND A VIGOROUS SHORT-WAVE TROUGH TO ITS NORTHWEST.  THE 
CYCLONE SHOULD CONTINUE TO MOVE NORTHEASTWARD AT ABOUT THE SAME
SPEED FOR ABOUT THE NEXT 36 H AND NEARLY ALL TRACK MODEL GUIDANCE
IS IN AGREEMENT WITH THIS.  HOWEVER...BEYOND 36 H...THE MODEL SUITE
SHOWS A TREMENDOUS DIVERGENCE THAT FALLS INTO TWO FACTIONS.  THE
NORTHERN GROUP...WITH MEMBERS AT FIVE DAYS JUST SOUTHEAST OF
NEWFOUNDLAND...INCLUDE THE HWRF/GFDL/NOGAPS MODELS.  THE ECMWF
LIKELY WOULD HAVE ALSO BEEN EXPLICITLY INCLUDED HERE...BUT IT
BECOMES ABSORBED BY A LARGE BAROCLINIC SYSTEM AFTER DAY THREE.  THE
SOUTHERN GROUP...WITH MEMBERS AT FIVE DAYS JUST NORTH OF THE
CARIBBEAN...INCLUDE THE GFS/GFS ENSEMBLE/UKMET.  THE FORECAST TRACK
CHOSEN LEANS MORE TOWARD THE LATTER BUNCH AND IS CONSIDERABLY SOUTH
OF THE MODEL CONSENSUS...WHICH IS AN UNREALISTIC PREDICTION...AND
SOMEWHAT SOUTH OF THE PREVIOUS ADVISORY.  IT ALMOST GOES WITHOUT
SAYING...THE EXTENDED FORECAST OF THIS SYSTEM IS VERY UNCERTAIN.

REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST
SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE
HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-
THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN
REPUBLIC DURING THE NEXT COUPLE OF DAYS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/2100Z 20.3N  73.8W    65 KT
 12HR VT     06/0600Z 22.0N  72.6W    70 KT
 24HR VT     06/1800Z 23.9N  71.5W    80 KT
 36HR VT     07/0600Z 24.8N  70.8W    75 KT
 48HR VT     07/1800Z 25.4N  69.6W    55 KT
 72HR VT     08/1800Z 26.5N  67.0W    30 KT
 96HR VT     09/1800Z 26.5N  63.5W    25 KT...POST-TROP/REMNT LOW
120HR VT     10/1800Z 27.0N  61.0W    25 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER LANDSEA/BEVEN
 

WTNT41 KNHC 060241
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT FRI NOV 05 2010
 
BEFORE DEPARTING EARLIER THIS EVENING...THE AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT FOUND A MAXIMUM 850-MB FLIGHT LEVEL WIND
OF 57 KT AND A RISING CENTRAL PRESSURE. THE SATELLITE APPEARANCE OF
THE CYCLONE HAD ALSO BECOME A BIT DISHEVELED EARLIER THIS EVENING
...HOWEVER COLD CLOUD TOPS HAVE AGAIN INCREASED NEAR THE ESTIMATED
CENTER LOCATION. THE INITIAL INTENSITY IS HELD AT 65 KT...AND THE
NEXT AIRCRAFT MISSION OVERNIGHT WILL HELP DETERMINE IF TOMAS HAS
WEAKENED BELOW HURRICANE INTENSITY. THE 20 KT OF SOUTHERLY SHEAR
OVER TOMAS ASSOCIATED WITH THE LARGE DEEP-LAYER TROUGH MOVING
ACROSS EASTERN NORTH AMERICA COULD BE PREVENTING THE CYCLONE FROM
STRENGTHENING FURTHER. CONSISTENT WITH THIS THINKING...AIRCRAFT
DATA AND RECENT MICROWAVE IMAGERY INDICATE THAT THE VORTEX IS NOW
TILTED NORTHEASTWARD WITH HEIGHT. GIVEN THE SHEAR AND THE RAPID
DETERIORATION OF THE MID-LEVEL ATMOSPHERIC THERMODYNAMICS AS
INDICATED BY THE SHIPS MODEL IN THE NEXT 12 TO 24 HOURS...TOMAS MAY
HAVE PEAKED IN INTENSITY. BEYOND 24 HOURS...THE SHEAR INCREASES
FURTHER...WHICH SHOULD RESULT IN WEAKENING. THE OFFICIAL INTENSITY
FORECAST HAS BEEN ADJUSTED DOWNWARD...AND SHOWS LITTLE CHANGE
THROUGH 12 HOURS FOLLOWED BY STEADY WEAKENING TO REMNANT LOW STATUS
IN 96 HOURS. THIS FORECAST IS CLOSE TO THE LGEM MODEL...WHICH IS
DESIGNED TO HANDLE CHANGING ENVIRONMENTAL CONDITIONS DURING THE
FORECAST PERIOD. 
 
THE LAST FEW AIRCRAFT FIXES INDICATE THAT TOMAS IS MOVING MORE TO
THE RIGHT...OR EASTWARD...THAN THE PREVIOUS FORECAST TRACK...AND
THE INITIAL MOTION ESTIMATE IS 045/11 KT. THE GLOBAL MODELS ARE IN
RELATIVELY GOOD AGREEMENT ON THE EVOLUTION OF THE LARGE-SCALE
PATTERN...WHICH IS DOMINATED BY A DEEP-LAYER TROUGH MOVING INTO THE
WESTERN ATLANTIC THAT WILL SLOW DOWN AS IT CUTS OFF OFFSHORE OF THE
NORTHEASTERN U.S. IN 2 OR 3 DAYS. SIGNIFICANT DIFFERENCES REMAIN IN
THE TRACK GUIDANCE AS TO WHETHER TOMAS WILL BE PULLED NORTHWARD
INTO THE SURFACE FRONTAL ZONE ASSOCIATED WITH THE TROUGH OR BE
SHEARED APART AND MOVE SLOWLY EASTWARD. THE GFS...ECMWF...AND UKMET
FAVOR THE LATTER SOLUTION AND LIE ON THE SOUTHERN SIDE OF THE
GUIDANCE ENVELOPE. THE GFDL...HWRF AND NOGAPS ARE FARTHER NORTH
WITH A DEEPER CYCLONE. GIVEN THE EXTREME SHEAR VALUES LATE IN THE
PERIOD AND AN ENVIRONMENT THAT APPEARS UNFAVORABLE FOR DEEP
CONVECTION...IT SEEMS UNLIKELY THAT TOMAS WILL REMAIN DEEP ENOUGH
TO BE PULLED TOO FAR NORTHWARD. THE OFFICIAL FORECAST FAVORS THE
SOUTHERN SOLUTION AND IS BASED ON A BLEND OF THE PREVIOUS FORECAST
AND THE TRACKS OF THE UKMET...GFS...AND ECMWF MODELS THROUGH 48
HOURS. AT DAYS 3 AND 4...THE NEW NHC FORECAST IS AN UPDATE OF THE
PREVIOUS ONE ADJUSTED FOR THE INITIAL POSITION AND MOTION. 
 
EVEN THOUGH THE CENTER OF TOMAS HAS PASSED NORTH OF HISPANIOLA...
SOUTHERLY FLOW BEHIND TOMAS WILL RESULT IN THE CONTINUATION OF A
SIGNIFICANT HEAVY RAINFALL THREAT FOR THE NEXT DAY OR TWO...WHICH
COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES OVER
PORTIONS OF HAITI AND THE DOMINICAN REPUBLIC. 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0300Z 20.8N  72.8W    65 KT
 12HR VT     06/1200Z 22.4N  71.7W    65 KT
 24HR VT     07/0000Z 23.9N  70.9W    60 KT
 36HR VT     07/1200Z 24.7N  70.1W    55 KT
 48HR VT     08/0000Z 25.0N  68.8W    45 KT
 72HR VT     09/0000Z 26.0N  66.0W    30 KT
 96HR VT     10/0000Z 26.0N  63.0W    20 KT...POST-TROP/REMNT LOW
120HR VT     11/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN/ROBERTS
 

WTNT41 KNHC 060848
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM EDT SAT NOV 06 2010
 
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS
FOUND 700-MB FLIGHT-LEVEL WINDS OF 63 KT...PEAK SURFACE SFMR WINDS
OF 50-55 KT....AND A CENTRAL PRESSURE OF 993 MB. SATELLITE IMAGERY
SHOWS THAT THE THE CONVECTIVE STRUCTURE OF THE CYCLONE CONSISTS OF
A CENTRAL MASS OF COLD-TOPPED CONVECTION...THOUGH CLOUD TOPS HAVE
BEEN WARMING RECENTLY. THE AIRCRAFT OBSERVATIONS ALSO INDICATE THAT
THE SURFACE AND FLIGHT-LEVEL CENTERS ARE MORE ALIGNED THAN THEY
WERE PREVIOUSLY. WITH NO OBSERVATIONS TO SUPPORT HURRICANE FORCE
WINDS...THE INITIAL INTENSITY IS LOWERED TO 60 KT FOR THIS
ADVISORY. TOMAS IS EXPECTED TO REMAIN IN RELATIVELY LOW VERTICAL
WIND SHEAR FOR UP TO ANOTHER 24 HOURS. HOWEVER...A LOW-LEVEL
BAROCLINIC ZONE ASSOCIATED WITH A LARGE DEEP-LAYER TROUGH OVER THE
EASTERN U.S. IS IMPINGING ON THE CIRCULATION OF THE HURRICANE. A
DRAMATIC INCREASE IN SHEAR IS FORECAST AFTER 24 HOURS...AND
THERMODYNAMIC PARAMETERS ARE EXPECTED TO BECOME INCREASINGLY
UNFAVORABLE. WEAKENING SEEMS IMMINENT...WITH THE RATE OF WEAKENING
LIKELY INCREASING AFTER 36 HOURS...GIVEN THE EXTREME AMOUNT OF
VERTICAL WIND SHEAR DEPICTED BY THE LARGE-SCALE MODELS. THE
OFFICIAL NHC FORECAST IS SIMILAR TO THE PREVIOUS ONE BUT INDICATES
TOMAS BECOMING A REMNANT LOW SOONER.
 
THE INITIAL MOTION IS 050/13...A BIT FASTER THAN THE PREVIOUS
ESTIMATE. GLOBAL MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH
RESPECT TO THE OVERALL ENVIRONMENTAL SYNOPTIC PATTERN DURING THE
NEXT SEVERAL DAYS. THE CYCLONE SHOULD MOVE NORTHEASTWARD DURING THE
NEXT 24-36 HOURS IN A DEEP LAYER OF SOUTHWESTERLY FLOW AHEAD OF A
MID- TO UPPER-LEVEL TROUGH MOVING FROM THE EASTERN U.S. INTO THE
WESTERN ATLANTIC. AFTER THAT...THE TRACK GUIDANCE DIVERGES... WITH
SEVERAL OF THE MORE RELIABLE MODELS SHOWING A HEAVILY SHEARED TOMAS
MOVING SLOWLY ON AN EASTWARD TRACK AT THE BASE OF THE WESTERN
ATLANTIC TROUGH. A SECOND CAMP OF MODELS SHOWS A DEEPER CYCLONE
BEING PULLED NORTHWARD AND BECOMING INVOLVED WITH THE BAROCLINIC
ZONE ASSOCIATED ASSOCIATED WITH THE SAME TROUGH. THE OFFICIAL
FORECAST CONTINUES TO FAVOR THE FORMER GROUP SINCE IT APPEARS
UNLIKELY THAT TOMAS WILL BE ABLE TO MANTAIN ITSELF AS A VIABLE
TROPICAL CYCLONE FOR LONG. THE NEW NHC FORECAST IS ADJUSTED TO THE
RIGHT DURING THE SHORT TERM TO ACCOUNT FOR THE CURRENT MORE
NORTHEASTERLY MOTION BUT IS SIMILAR TO THE PREVIOUS FORECAST BEYOND
48 HOURS.
 
EVEN THOUGH THE CENTER OF TOMAS HAS PASSED NORTH OF HISPANIOLA...
SOUTHERLY FLOW BEHIND TOMAS WILL RESULT IN THE CONTINUATION OF A
HEAVY RAINFALL THREAT FOR THE NEXT DAY OR TWO...WHICH
COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES OVER
PORTIONS OF HAITI AND THE DOMINICAN REPUBLIC.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0900Z 21.9N  71.3W    60 KT
 12HR VT     06/1800Z 23.2N  70.2W    60 KT
 24HR VT     07/0600Z 24.2N  69.4W    55 KT
 36HR VT     07/1800Z 24.7N  68.7W    50 KT
 48HR VT     08/0600Z 25.0N  67.5W    40 KT
 72HR VT     09/0600Z 25.5N  65.0W    25 KT...POST-TROP/REMNT LOW
 96HR VT     10/0600Z 26.5N  60.9W    20 KT...POST-TROP/REMNT LOW
120HR VT     11/0600Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN/FRANKLIN
 

WTNT41 KNHC 061502
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT SAT NOV 06 2010

A NOAA HURRICANE HUNTER AIRCRAFT REPORTED 850 MB FLIGHT-LEVEL WINDS
OF 69 KT TO THE SOUTHEAST OF THE CENTER OF TOMAS...WITH SFMR WINDS
OF 54 KT.  THE MINIMUM CENTRAL PRESSURE HAS BEEN IN THE 990-992 MB
RANGE DURING THE LAST SEVERAL FIXES.  BASED ON THESE DATA...THE
INITIAL INTENSITY IS NUDGED DOWNWARD TO 55 KT.  THE STORM STILL HAS
A SYMMETRIC BANDED CONVECTIVE PATTERN...AND A RECENT WINDSAT
OVERPASS SHOWS A WELL-DEFINED LOW-LEVEL STRUCTURE.  HOWEVER...
COLD-AIR CLOUDS ARE PRESENT IN SATELLITE IMAGERY NEAR THE WESTERN
EDGE OF CONVECTION...INDICATING THAT A COLD FRONT IS APPROACHING
THE CYCLONE.

THE INITIAL MOTION IS 045/14.  ALL GUIDANCE INDICATES THAT TOMAS
SHOULD SLOW ITS FORWARD MOTION DURING THE NEXT 24 HR AS PRESSURES
RISES TO THE NORTH OF THE CYCLONE AND FALL TO THE EAST OF IT. 
AFTER THAT TIME...ANOTHER ROUND OF BAROCLINIC CYCLOGENESIS SHOULD
OCCUR OVER THE NORTHWESTERN ATLANTIC...WITH A NEW DEEP-LAYER LOW
DEVELOPING TO THE NORTH OF TOMAS.  WHILE THERE ARE SIGNIFICANT
DIFFERENCES IN THE DETAILS BETWEEN THE DYNAMICAL MODELS...THEY ALL
FORECAST THIS NEW SYSTEM TO TURN TOMAS EASTWARD.  THERE REMAINS A
LARGE AMOUNT OF SPREAD IN THE TRACK GUIDANCE AFTER 48 HR...AS THE
GFS/ECMWF FAVORING A SLOWER MOTION AT LOWER LATITUDE...WHILE
GFDL/HWRF/NOGAPS/UKMET/GFS ENSEMBLE MEAN NOW FAVOR A FASTER MOTION
AT HIGHER LATITUDE.  THE NEW FORECAST TRACK IS A BLEND OF THESE
EXTREMES IN BOTH DIRECTION AND SPEED...AND IS SLOWER THAN THE
CONSENSUS MODELS.  THE NEW TRACK IS SHIFTED A LITTLE TO THE WEST OF
THE PREVIOUS FORECAST DURING THE FIRST 24 HR...AND A LITTLE TO THE
NORTH THEREAFTER.

TOMAS HAS BEEN SLOWLY WEAKENING EVEN THOUGH THE VERTICAL WIND SHEAR
REMAINS LIGHT AND THE SEA SURFACE TEMPERATURES WARM.  BASED ON
THIS...LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE FIRST 24 HR
OF THE FORECAST. HOWEVER...GIVEN THE STRUCTURE...THERE IS STILL
SOME CHANCE OF RE-INTENSIFICATION DURING THIS TIME.  TOMAS SHOULD
ENCOUNTER SIGNIFICANT AMOUNTS OF COOLER/DRIER AIR AND INCREASING
WIND SHEAR AFTER 24 HR...WHICH SHOULD CAUSE A STEADY AND POSSIBLY
RAPID WEAKENING.  THE LATTER PART OF THE NEW INTENSITY FORECAST
CALLS FOR THE CYCLONE TO DEGENERATE INTO A REMNANT LOW BY 72 HR AND
TO DISSIPATE COMPLETELY BY 120 HR.  THERE IS A POSSIBILITY TOMAS
COULD UNDERGO EXTRATROPICAL TRANSITION INSTEAD OF
DEGENERATION...ESPECIALLY IF IT TAKES A MORE NORTHERLY COURSE AND
INTERACTS WITH THE WESTERN ATLANTIC BAROCLINIC LOW.
 
TOMAS IS NOW FAR ENOUGH TO THE NORTH AND EAST THAT THE THREAT OF
WIDESPREAD HEAVY RAINS HAS DIMINISHED OVER HAITI AND THE DOMINICAN
REPUBLIC.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/1500Z 23.1N  70.6W    55 KT
 12HR VT     07/0000Z 24.1N  69.9W    55 KT
 24HR VT     07/1200Z 24.8N  69.3W    55 KT
 36HR VT     08/0000Z 25.1N  68.5W    50 KT
 48HR VT     08/1200Z 25.4N  66.5W    40 KT
 72HR VT     09/1200Z 26.5N  62.5W    25 KT...POST-TROP/REMNT LOW
 96HR VT     10/1200Z 28.0N  58.0W    20 KT...POST-TROP/REMNT LOW
120HR VT     11/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 062051
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  35
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM EDT SAT NOV 06 2010
 
TOMAS HAS MAINTAINED DEEP CONVECTION THIS AFTERNOON AND BRIEFLY AN
EYE MAY HAVE TRIED TO FORM.  A PARTIAL EYEWALL WAS ALSO PRESENT IN
THE 1743Z AQUA MICROWAVE IMAGERY.  IN THE LAST COUPLE OF HOURS...
HOWEVER...THIS FEATURE IS NO LONGER PRESENT AND THE CONVECTIVE
STRUCTURE IS SHOWING LESS BANDING CHARACTERISTICS.  THE INITIAL
INTENSITY IS KEPT AT 55 KT...WHICH IS CONSISTENT WITH A BLEND OF
TAFB AND SAB DVORAK CLASSIFICATIONS.
 
DATA FROM NOAA BUOY 41046 INDICATES THAT THE STRONG COLD FRONT
OFF OF THE SOUTHEAST U.S. COAST IS NOW IMPACTING THE OUTER
CIRCULATION OF TOMAS.  WIND...TEMPERATURE...AND DEWPOINT
OBSERVATIONS FROM THE BUOY SHOWED THAT THE FRONT HAS REACHED THAT
LOCATION.  THE INNER CORE OF TOMAS APPEARS...FOR THE MOMENT...TO BE
UNAFFECTED BY THE COOLER/DRIER AIR.  IT IS LIKELY THAT TOMAS WILL
SOON BEGIN ITS FINAL DEMISE WITH BOTH THE FRONTAL AIRMASS AND
INCREASINGLY STRONG VERTICAL SHEAR IMPACTING THE CYCLONE.  THE
INTENSITY FORECAST IS SOMEWHAT BELOW BOTH THE INTENSITY MODEL
CONSENSUS AND THE PREVIOUS ADVISORY.  THE SYSTEM SHOULD DROP BELOW
TROPICAL STORM INTENSITY AFTER 48 H...BUT COULD OCCUR EARLIER IF
THE ANTICIPATED VERY STRONG SHEAR AND DRY AIR REMOVES ALL OF THE
DEEP CONVECTION.  IT SHOULD BE NOTED THAT TOMAS COULD UNDERGO
EXTRATROPICAL TRANSITION INSTEAD OF DEGENERATION...ESPECIALLY IF IT
GOES NORTH OF THE FORECAST TRACK AND MORE STRONGLY INTERACTS WITH A
BAROCLINIC LOW FORECAST TO DEVELOP OVER THE WESTERN ATLANTIC.
 
TOMAS IS CURRENTLY MOVING 30/13...AS IT IS PRIMARILY BEING STEERED
BY A VIGOROUS SHORT-WAVE TROUGH TO ITS NORTHWEST.  THE TRACK MODEL
GUIDANCE IS IN MUCH BETTER AGREEMENT THIS AFTERNOON.  THE CYCLONE
SHOULD RATHER ABRUPTLY DECELERATE AND TURN TOWARD THE EAST IN ABOUT
12-24 H...ONCE THE DEEP CONVECTION IS EITHER DECOUPLED FROM THE
LOW-LEVEL CIRCULATION OR COMPLETELY ELIMINATED.  THEREAFTER...THE
SYSTEM SHOULD BE ADVECTED TOWARD THE EAST AND THEN THE NORTHEAST BY
THE LARGE BAROCLINIC LOW.  THE TRACK FORECAST IS FARTHER NORTH AND
FASTER THAN THE PREVIOUS ADVISORY BUT NOT AS QUICK AS THE MODEL
CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/2100Z 24.2N  70.0W    55 KT
 12HR VT     07/0600Z 25.2N  69.3W    50 KT
 24HR VT     07/1800Z 25.6N  68.6W    45 KT
 36HR VT     08/0600Z 25.8N  67.2W    40 KT
 48HR VT     08/1800Z 26.5N  64.9W    35 KT
 72HR VT     09/1800Z 28.5N  59.5W    25 KT...POST-TROP/REMNT LOW
 96HR VT     10/1800Z 31.5N  55.5W    20 KT...POST-TROP/REMNT LOW
120HR VT     11/1800Z...DISSIPATED
 
$$
FORECASTER LANDSEA/BEVEN
 

WTNT41 KNHC 062343
TCDAT1
HURRICANE TOMAS SPECIAL DISCUSSION NUMBER  36
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
800 PM AST SAT NOV 06 2010

DESPITE THE SOMEWHAT RAGGED APPEARANCE OF THE SYSTEM IN INFRARED
IMAGERY...DATA FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT
TOMAS HAS RE-INTENSIFIED TO HURRICANE STRENGTH. THE AIRCRAFT
MEASURED A PEAK 700-MB FLIGHT LEVEL WIND OF 79 KT EAST OF THE
CENTER AND A MAXIMUM SFMR WIND OF 64 KT. BASED ON THESE DATA...THE
INITIAL INTENSITY IS SET TO 70 KT FOR THIS SPECIAL ADVISORY. THE
INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD THROUGH 24 HOURS TO
ACCOUNT FOR THE RE-INTENSIFICATION...AND THE RADII HAVE BEEN
MODIFIED ACCORDINGLY. BEYOND 24 HOURS...THE INTENSITY FORECAST
REMAINS THE SAME AS THE PREVIOUS PACKAGE...AS INCREASING SHEAR AND
DRY AIR SHOULD EVENTUALLY LEAD TO WEAKENING.

RECENT MICROWAVE IMAGERY AND DATA FROM THE AIRCRAFT INDICATE THAT
TOMAS IS MOVING A LITTLE TO THE LEFT OF THE PREVIOUS TRACK...AND
THE INITIAL MOTION ESTIMATE IS 020/13 KT. THE OFFICIAL TRACK
FORECAST HAS BEEN ADJUSTED TO THE LEFT...OR NORTH...THROUGH 36
HOURS TO ACCOUNT FOR THE INITIAL POSITION AND MOTION. BEYOND 36
HOURS...THE TRACK FORECAST IS UNCHANGED FROM THE PREVIOUS PACKAGE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0000Z 25.0N  69.7W    70 KT
 12HR VT     07/0600Z 25.7N  69.3W    60 KT
 24HR VT     07/1800Z 26.0N  68.6W    50 KT
 36HR VT     08/0600Z 26.0N  67.2W    40 KT
 48HR VT     08/1800Z 26.5N  64.9W    35 KT
 72HR VT     09/1800Z 28.5N  59.5W    25 KT...POST-TROP/REMNT LOW
 96HR VT     10/1800Z 31.5N  55.5W    20 KT...POST-TROP/REMNT LOW
120HR VT     11/1800Z...DISSIPATED
 
$$
FORECASTER BRENNAN/BROWN
 

WTNT41 KNHC 070230
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  37
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM AST SAT NOV 06 2010
 
BEFORE EXITING TOMAS...THE NOAA HURRICANE HUNTER AIRCRAFT REPORTED A
700-MB FLIGHT-LEVEL WIND MAXIMUM OF 75 KT...A PEAK SFMR WIND OF 61
KT...AND A CENTRAL PRESSURE OF 987 MB. THIS SUGGESTS THAT THE
INTENSITY HAS LEVELED OFF...AND THE INITIAL INTENSITY REMAINS 70
KT. WHILE THE INITIAL SHEAR VALUES FROM SHIPS AND UW-CIMMS ARE
15-20 KT...TOMAS OBVIOUSLY HAS NOT YET FELT THE EFFECTS OF THIS
SHEAR IN THE INNER CORE. HOWEVER...WATER VAPOR IMAGERY AND GOES
CLOUD TRACK WINDS SHOW STRONG UPPER-LEVEL SOUTHERLY FLOW AND DRY
AIR INCHING CLOSER TO TOMAS...AND THE SHEAR SHOULD INCREASE
MARKEDLY IN THE NEXT 12 HOURS. IN FACT...THE SHIPS MODEL SHOWS
SHEAR VALUES OF AROUND 50 KT IN 24 HOURS. THE SHEAR...DRIER
MID-LEVEL AIR...AND COOLER WATERS SHOULD RESULT IN STEADY
WEAKENING...REDUCING TOMAS TO A REMNANT LOW IN 3 DAYS WITH
DISSIPATION EXPECTED IN ABOUT 4 DAYS. THE NEW NHC INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ONE...AND IS CLOSEST TO THE
SHIPS MODEL AFTER 24 HOURS. 
 
SATELLITE IMAGERY SUGGESTS THAT TOMAS MAY BE SLOWING DOWN...AND THE
INITIAL MOTION ESTIMATE IS 025/9. THERE IS GOOD AGREEMENT IN THE
GUIDANCE SLOWING TOMAS EVEN FURTHER IN THE NEXT 12 HOURS. AFTER
THAT TIME...TOMAS SHOULD BE STEERED EAST-NORTHEASTWARD FOR A DAY OR
TWO BY THE DEEP-LAYER TROUGH/LOW ADVANCING INTO THE WESTERN
ATLANTIC. A TURN BACK TOWARD THE NORTHEAST IS EXPECTED IN ABOUT 72
HOURS...AS WHAT IS LEFT OF TOMAS IS PULLED NORTHWARD AHEAD OF THE
WESTERN ATLANTIC LOW. THE GFS AND ECMWF MODELS SHOW THE CIRCULATION
OF TOMAS DISSIPATING BY 96 HOURS...AND DISSIPATION IS ALSO
INDICATED BY THE SHIPS MODEL BY THAT TIME. IT IS WORTH NOTING
THAT THE UKMET MAINTAINS TOMAS AS A DEEPER CYCLONE AND TAKES IT
FARTHER NORTHWARD BEFORE MERGING IT WITH A FRONTAL ZONE. HOWEVER...
THIS SCENARIO SEEMS UNLIKELY GIVEN THAT TOMAS SHOULD HAVE DIFFICULTY
REMAINING A DEEP CYCLONE DUE TO THE SHEAR AND UNFAVORABLE
THERMODYNAMIC CONDITIONS. THE NEW NHC TRACK FORECAST IS A BLEND OF
THE PREVIOUS ADVISORY AND THE NEW MULTI-MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0300Z 25.2N  69.6W    70 KT
 12HR VT     07/1200Z 25.8N  69.2W    60 KT
 24HR VT     08/0000Z 26.1N  68.1W    50 KT
 36HR VT     08/1200Z 26.5N  66.1W    40 KT
 48HR VT     09/0000Z 27.4N  63.2W    35 KT
 72HR VT     10/0000Z 31.0N  57.5W    25 KT...POST-TROP/REMNT LOW
 96HR VT     11/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 070848
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER  38
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 AM AST SUN NOV 07 2010
 
AROUND 06Z...A BURST OF DEEP CONVECTION WITH TOPS COLDER THAN -80C
DEVELOPED NEAR THE CENTER...AND A WARM SPOT OR EYE FEATURE BRIEFLY
BECAME EVIDENT IN INFRARED IMAGERY. SINCE THAT TIME...HOWEVER...
CLOUD TOPS HAVE WARMED AND THE UPPER-LEVEL OUTFLOW HAS BECOME
FLATTENED ON THE WEST SIDE AS WESTERLY SHEAR HAS STARTED TO IMPINGE
ON THE CYCLONE. A SATELLITE INTENSITY ESTIMATE OF T4.0/65 KT FROM
TAFB ALONG WITH AODT AND UW-CIMSS ADT ESTIMATES OF T4.3/72 KT
SUPPORT MAINTAINING A SYNOPTIC INTENSITY OF 70 KT AT 06Z.
HOWEVER...GIVEN THE RECENT DISHEVELED APPEARANCE TO THE CONVECTIVE
CLOUD MASS...THE 09Z ADVISORY INTENSITY IS BEING LOWERED TO 65 KT.

THE INITIAL MOTION ESTIMATE IS 040/06. SATELLITE IMAGERY DURING THE
PAST COUPLE OF HOURS SUGGESTS THAT TOMAS HAS SLOWED DOWN AND TURNED
TOWARD THE NORTHEAST SINCE THE 06Z FIXES. A TURN TOWARD THE
EAST-NORTHEAST IS EXPECTED WITHIN THE NEXT 12 HOURS OR SO AS
INCREASING WEST-SOUTHWESTERLY MID-/UPPER-LEVEL FLOW AHEAD OF A
BROAD EASTWARD-MOVING TROUGH GRADUALLY DECOUPLES THE LOW- AND
UPPER-LEVELS CIRCULATIONS...LEAVING THE LOW-LEVEL CIRCULATION TO BE
STEERED EASTWARD BY WEAKER FLOW AHEAD OF A COLD FRONT. BY 48
HOURS...TOMAS IS FORECAST TO DEGENERATE INTO A NON-CONVECTIVE
REMNANT LOW PRESSURE SYSTEM...WHICH IS THEN EXPECTED TO BE
CAPTURED BY AND PULLED NORTHEASTWARD INTO A LARGE EXTRATROPICAL
CYCLONE AFTER 72 HOURS. MOST OF THE NHC MODEL GUIDANCE IS IN GOOD
AGREEMENT ON THIS DEVELOPING SCENARIO. THE OFFICIAL FORECAST TRACK
IS SIMILAR TO THE PREVIOUS ADVISORY TRACK AND LIES ALONG THE
NORTHERN EDGE OF THE GUIDANCE ENVELOPE.
 
WATER VAPOR IMAGERY AND SATELLITE-DERIVED WINDS INDICATE 40-50 KT
WEST-SOUTHWESTERLY MID-LEVEL FLOW IS BEGINNING TO UNDERCUT THE
HIGH-LEVEL OUTFLOW LAYER OF TOMAS. AS A RESULT...ASSOCIATED STRONG
VERTICAL WIND SHEAR SHOULD INDUCE WEAKENING WITHIN THE NEXT 6-12
HOURS...AND TROPICAL CYCLONE DISSIPATION SHOULD BE COMPLETE BY 48
HOURS. THE OFFICIAL INTENSITY FORECAST TRACK IS SIMILAR TO THE
PREVIOUS ADVISORY AND IS CLOSE TO A BLEND OF THE SHIPS AND LGEM
INTENSITY MODELS. HOWEVER...THE COMBINATION OF STRONG WESTERLY
SHEAR AND VERY DRY MID-LEVEL AIR COULD RESULT IN MORE RAPID
WEAKENING THAN CURRENTLY FORECAST. 
 
THE 34-KT WIND RADII AND 12-FT SEAS RADII HAVE BEEN EXPANDED IN THE
WESTERN SEMICIRCLE BASED ON REPORTS FROM NOAA BUOYS 41047 AND
41047. THE INCREASE IN THE OUTER WIND FIELD IS DUE TO A STRONG COLD
FRONT AND HIGH PRESSURE SYSTEM MOVING CLOSER TO TOMAS...WHICH HAS
ACTED TO TIGHTEN UP THE PRESSURE GRADIENT ON THE WEST SIDE OF THE
HURRICANE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0900Z 26.2N  68.8W    65 KT
 12HR VT     07/1800Z 26.5N  68.2W    60 KT
 24HR VT     08/0600Z 26.8N  66.6W    50 KT
 36HR VT     08/1800Z 27.5N  64.2W    40 KT
 48HR VT     09/0600Z 28.6N  61.3W    30 KT...POST-TROP/REMNT LOW
 72HR VT     10/0600Z 33.0N  55.5W    25 KT...POST-TROP/REMNT LOW
 96HR VT     11/0600Z...DISSIPATED
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 071441
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  39
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM AST SUN NOV 07 2010
 
TOMAS HAS WEAKENED RAPIDLY DURING THE LAST SEVERAL HOURS.  DEEP
CONVECTION HAS WITHERED AWAY...DUE TO ABOUT 35 KT OF WESTERLY
SHEAR...WITH ONLY A VERY SMALL AREA OF THUNDERSTORMS REMAINING NEAR
THE CENTER.  THE INITIAL INTENSITY IS ESTIMATED TO BE 50 KT...BASED
ON A BLEND OF OBJECTIVE AND SUBJECTIVE SATELLITE INTENSITY
ESTIMATES AND WIND REPORTS FROM BUOY 41047.  TOMAS ALSO APPEARS TO
BE GRADUALLY LOSING ITS TROPICAL CHARACTERISTICS.  SATELLITE IMAGES
SHOW COLD AIR STRATOCUMULUS CLOUDS WRAPPING AROUND THE WESTERN AND
SOUTHERN PORTIONS OF THE CIRCULATION...AND SHIP REPORTS SUGGEST
THAT THE SYSTEM COULD BE DEVELOPING FRONTAL BOUNDARIES.  THE
GFS-BASED SHIPS MODEL SHOWS THE SHEAR INCREASING FURTHER...TO NEAR
50 KT IN 12 HOURS.  THIS...COMBINED WITH MID-LEVEL RELATIVE
HUMIDITIES BELOW 40 PERCENT...AND COOL WATERS SHOULD CAUSE
TOMAS TO BECOME POST-TROPICAL LATER TODAY OR TONIGHT.
 
AN 0624 UTC AMSU OVERPASS AND A 1014 UTC SSMIS IMAGE INDICATE THAT
THE LOW-LEVEL CENTER IS LOCATED ABOUT 50 N MI WEST OF THE PREVIOUS
ESTIMATE.  THESE DATA ALSO SUGGEST THAT TOMAS HAS SLOWED DOWN
SUBSTANTIALLY AND TURNED NORTHWARD DURING THE PAST 12-18 HOURS...
RESULTING IN AN INITIAL MOTION ESTIMATE OF 005/5.  THE CYCLONE IS
EXPECTED TO MOVE IN A MOTION BETWEEN NORTHEAST AND EAST-NORTHEAST
WITH A GRADUAL INCREASE IN FORWARD SPEED...TO THE SOUTH AND
SOUTHEAST OF A STRENGTHENING LARGE BAROCLINIC LOW OVER THE NORTH
ATLANTIC. THIS MUCH LARGER LOW SHOULD ABSORB WHATEVER IS LEFT OF
TOMAS IN ABOUT 4 DAYS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/1500Z 26.0N  69.6W    50 KT
 12HR VT     08/0000Z 26.4N  68.7W    45 KT...POST-TROPICAL
 24HR VT     08/1200Z 26.9N  66.5W    35 KT...POST-TROPICAL
 36HR VT     09/0000Z 27.9N  63.9W    30 KT...POST-TROP/REMNT LOW
 48HR VT     09/1200Z 30.0N  61.0W    25 KT...POST-TROP/REMNT LOW
 72HR VT     10/1200Z 36.0N  57.0W    25 KT...POST-TROP/REMNT LOW
 96HR VT     11/1200Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI
 

WTNT41 KNHC 072032
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  40
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
500 PM AST SUN NOV 07 2010
 
SATELLITE IMAGES...SURFACE OBSERVATIONS...AND MODEL ANALYSES
INDICATE THAT TOMAS HAS ACQUIRED FRONTAL CHARACTERISTICS.  COLD AIR
STRATOCUMULUS CLOUDS ARE NOW WRAPPING INTO THE INNER-CORE REGION...
AND ANY LINGERING DEEP CLOUDINESS APPEARS MORE ASSOCIATED WITH THE
FRONTAL BOUNDARIES.  THEREFORE...TOMAS IS NO LONGER CONSIDERED A
TROPICAL CYCLONE...AND THIS IS THE LAST ADVISORY ISSUED BY THE
NATIONAL HURRICANE CENTER ON THIS SYSTEM.
 
AN ASCAT PASS AROUND 1500 UTC SHOWED MAXIMUM WINDS IN THE 45-50 KT
RANGE OVER THE SOUTHWESTERN QUADRANT...AND THAT IS THE BASIS FOR
THE INITIAL INTENSITY.  STEADY WEAKENING OF THE POST-TROPICAL
CYCLONE IS EXPECTED DURING THE NEXT FEW DAYS.
 
THE INITIAL MOTION ESTIMATE IS 020/3.  THE POST-TROPICAL CYCLONE IS
FORECAST TO MOVE NORTHEASTWARD OR EAST-NORTHEASTWARD WITH A GRADUAL
INCREASE IN FORWARD SPEED UNTIL IT BECOMES ABSORBED BY A MUCH
LARGER BAROCLINIC LOW OVER THE NORTH ATLANTIC IN 3 TO 4 DAYS.
 
FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE TROPICAL ANALYSIS AND FORECAST BRANCH...
UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/2100Z 26.1N  69.1W    50 KT...POST-TROP/EXTRATROP
 12HR VT     08/0600Z 26.3N  67.9W    40 KT...POST-TROP/EXTRATROP
 24HR VT     08/1800Z 26.8N  65.6W    30 KT...POST-TROP/EXTRATROP
 36HR VT     09/0600Z 28.4N  62.8W    25 KT...POST-TROP/EXTRATROP
 48HR VT     09/1800Z 30.6N  60.0W    25 KT...POST-TROP/EXTRATROP
 72HR VT     10/1800Z 37.0N  56.5W    20 KT...POST-TROP/EXTRATROP
 96HR VT     11/1800Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI/BROWN
 

