WTNT44 KNHC 071457
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 AM AST WED SEP 07 2011
 
CONSIDERING THAT THERE WERE TROPICAL STORM FORCE WINDS IN AN EARLIER
ASCAT PASS AND A RECENT ONE WITH STRONGER WINDS...THE DEPRESSION HAS
BEEN UPGRADED TO TROPICAL STORM MARIA WITH AN INITIAL INTENSITY OF
45 KNOTS. THE CONVECTION IS NOT VERY DEEP AT THIS TIME AND THE ONLY
IMPRESSIVE FEATURE OF THE OVERALL CLOUD PATTERN IS A CURVED BAND TO
THE NORTH OF THE CENTER. THE OUTFLOW IS WELL ESTABLISHED IN THE
WESTERN SEMICIRCLE. GLOBAL MODELS SUGGEST THAT THE UPPER-LEVEL
WINDS WILL BE ONLY MARGINALLY FAVORABLE FOR STRENGTHENING DUE TO
THE PRESENCE OF SOUTHEASTERLY SHEAR. IN FACT...NEITHER SHIPS NOR
LGEM DEVELOPS THE CYCLONE TOO MUCH. THE MOST AGGRESSIVE MODEL IS
THE GFDL AND IT ONLY INTENSIFIES THE CYCLONE NEAR THE END OF THE
FORECAST PERIOD. GIVEN SUCH GUIDANCE...THE OFFICIAL FORECAST CALLS
FOR A SLIGHT STRENGTHENING ONLY.
 
MARIA IS RACING TOWARD THE WEST OR 280 DEGREES AT 20 KNOTS. MOST OF
THE TRACK MODELS...WHICH ARE IN EXCELLENT AGREEMENT...KEEP MARIA ON
THIS GENERAL HEADING WITH THE SAME SPEED FOR THE NEXT 2 TO 3 DAYS.
ONCE MARIA REACHES THE EXTREME NORTHEASTERN CARIBBEAN SEA IN ABOUT 3
DAYS...THE STEERING CURRENTS WEAKEN A LITTLE BIT AND THE CYCLONE
SHOULD DECREASE IN FORWARD SPEED. A TURN TO THE WEST-NORTHWEST
AROUND THE WESTERN EDGE OF THE SUBTROPICAL RIDGE SHOULD THEN BEGIN. 
THE OFFICIAL FORECAST LIES IN THE MIDDLE OF THE GUIDANCE ENVELOPE
WHICH IS BOUNDED BY THE GFS ON THE NORTH AND THE ECMWF ON THE
SOUTH.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/1500Z 13.0N  42.0W   45 KT  50 MPH
 12H  08/0000Z 13.5N  45.0W   45 KT  50 MPH
 24H  08/1200Z 14.0N  49.0W   45 KT  50 MPH
 36H  09/0000Z 14.5N  53.0W   50 KT  60 MPH
 48H  09/1200Z 15.5N  56.5W   55 KT  65 MPH
 72H  10/1200Z 17.5N  62.0W   55 KT  65 MPH
 96H  11/1200Z 20.0N  66.0W   55 KT  65 MPH
120H  12/1200Z 23.0N  70.0W   55 KT  65 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 072040
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 PM AST WED SEP 07 2011
 
THE OVERALL CLOUD PATTERN IS APPARENTLY WELL ORGANIZED ON VISIBLE
IMAGES...BUT NOT REALLY. THE LOW-LEVEL CENTER IS LOCATED ON THE
SOUTHWEST EDGE OF THE CONVECTION AND MOST OF THE ORGANIZED
RAINBANDS ARE SHIFTING TO THE NORTHEASTERN PORTION OF THE CYCLONE.
THIS WAS CONFIRMED BY RECENT MICROWAVE IMAGES. THE OUTFLOW IS
BECOMING DISRUPTED DUE A DEVELOPING WIND SHEAR AS FORECAST BY
GLOBAL MODELS AND THE SHIPS GUIDANCE. THE SHEAR IS INCREASING...BUT
IS NOT EXPECTED TO BE COMPLETELY HOSTILE TO THE CYCLONE. THE SHEAR
IN COMBINATION WITH THE RAPID FORWARD SPEED SUPPORT KEEPING MARIA
WITH LITTLE CHANGE IN INTENSITY THROUGH FIVE DAYS AS SUGGESTED BY
THE LGEM. ONLY THE GFDL MODEL INSISTS ON INTENSIFICATION. THE
CYCLONE IS APPROACHING NOAA BUOY 41041...SO WE WILL LIKELY KNOW
MORE ABOUT THE STRUCTURE OF MARIA LATER TONIGHT.
 
THE AVERAGE MOTION HAS BEEN TOWARD THE WEST OR 275 DEGREES AT 20
KNOTS. FOR THE NEXT 24 TO 36 HOURS...ALL MODELS ARE IN EXCELLENT
AGREEMENT FORECASTING MARIA TOWARD THE WEST OR WEST-NORTHWEST AT A
RAPID PACE. THEREAFTER...IT IS DEJA VU ALL OVER AGAIN WITH THE
TROUGH ALONG THE EAST COAST OF THE UNITED STATES AND THE
SUBTROPICAL RIDGE TO THE NORTH OF THE CYCLONE. THIS HAS BEEN THE
SCENARIO OBSERVED DURING THE TWO OR THREE PREVIOUS RECURVING
CYCLONES THIS SEASON. GIVEN THIS PATTERN...SOME MODELS LIKE THE GFS
AND HWRF TURN THE CYCLONE NORTHWESTWARD AND NORTHWARD AND THE ECMWF
AND UK PROLONGING THE EVENTUAL NORTHWARD TURN A LITTLE LONGER.  THE
OFFICIAL FORECAST IS...AS USUAL...A BLEND OF THESE GUIDANCE.
   
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/2100Z 13.2N  44.2W   45 KT  50 MPH
 12H  08/0600Z 13.6N  47.1W   45 KT  50 MPH
 24H  08/1800Z 14.5N  51.5W   45 KT  50 MPH
 36H  09/0600Z 15.0N  55.0W   45 KT  50 MPH
 48H  09/1800Z 16.0N  58.5W   45 KT  50 MPH
 72H  10/1800Z 18.5N  63.5W   45 KT  50 MPH
 96H  11/1800Z 22.0N  68.0W   45 KT  50 MPH
120H  12/1800Z 25.0N  70.0W   45 KT  50 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 080308
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 PM AST WED SEP 07 2011
 
MARIA HAS CHANGED LITTLE IN ORGANIZATION OVER THE PAST SEVERAL
HOURS...WITH THE LOW-LEVEL CENTER DISPLACED TO THE SOUTHWESTERN
EDGE OF THE DEEP CONVECTION BY SOUTHWESTERLY VERTICAL WIND SHEAR.
SATELLITE INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND 35 KT FROM
SAB...WHILE NOAA BUOY 41041 JUST REPORTED 1-MINUTE MEAN WINDS OF
43 KT.  BASED ON THIS THE INITIAL INTENSITY REMAINS 45 KT.
 
THE INITIAL MOTION IS A FAST 275/20.  MARIA IS CURRENTLY ON THE
SOUTH SIDE OF A STRONG LOW/MID-LEVEL SUBTROPICAL RIDGE...AND THIS
SHOULD KEEP THE STORM MOVING QUICKLY WESTWARD FOR THE NEXT
24 HOURS OR SO.  FROM 24-72 HOURS...MARIA SHOULD APPROACH A WEAKNESS
IN THE RIDGE CAUSED BY AN UPPER-LEVEL LOW...WHICH SHOULD ALLOW THE
CYCLONE TO TURN WEST-NORTHWESTWARD WITH SOME DECREASE IN FORWARD
SPEED.  THE FORECAST TRACK IS MORE UNCERTAIN AFTER 72 HOURS AS
MARIA APPROACHES THE WESTERN END OF THE SUBTROPICAL RIDGE AND A
DEEP-LAYER TROUGH MOVES EASTWARD THROUGH THE EASTERN UNITED STATES.
WHILE THE GUIDANCE GENERALLY SHOWS A TURN TOWARD THE NORTHWEST...
THERE IS A SIGNIFICANT SPREAD BETWEEN THE MORE WESTERLY GFDL/ECMWF
AND THE MORE EASTERLY GFS/NOGAPS.  THE NEW FORECAST TRACK IS
SHIFTED A LITTLE TO THE SOUTH OF THE PREVIOUS TRACK DURING THE
FIRST 48 HOURS...THEN IS CLOSE TO THE THE PREVIOUS TRACK AFTER THAT
TIME.  THE NEW TRACK LIES CLOSE TO THE CENTER OF THE GUIDANCE
ENVELOPE AND THE VARIOUS CONSENSUS MODELS.
 
SIGNIFICANT SOUTHWESTERLY TO WESTERLY SHEAR IS EXPECTED TO CONTINUE
FOR THE NEXT 48-72 HOURS...AND THE NEW INTENSITY FORECAST CONTINUES
TO CALL FOR LITTLE CHANGE IN STRENGTH DURING THAT TIME.  AFTER THAT
THERE IS A POSSIBILITY THAT MARIA MAY FIND A DECREASED SHEAR
ENVIRONMENT...ALTHOUGH THE FORECAST PRESENCE OF THE UPPER-LEVEL LOW
NEAR THE STORM MAKES THIS UNCERTAIN.  ALL THE INTENSITY GUIDANCE
SHOWS STRENGTHENING AFTER 72 HOURS...SO THE INTENSITY FORECAST NOW
CALLS FOR SOME MODEST STRENGTHENING DURING THAT TIME.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/0300Z 13.4N  46.2W   45 KT  50 MPH
 12H  08/1200Z 13.7N  49.2W   45 KT  50 MPH
 24H  09/0000Z 14.3N  53.3W   45 KT  50 MPH
 36H  09/1200Z 15.1N  56.7W   45 KT  50 MPH
 48H  10/0000Z 16.1N  59.7W   45 KT  50 MPH
 72H  11/0000Z 19.0N  64.5W   45 KT  50 MPH
 96H  12/0000Z 22.5N  68.5W   50 KT  60 MPH
120H  13/0000Z 25.5N  71.0W   60 KT  70 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 080833
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 AM AST THU SEP 08 2011

MARIA CURRENTLY HAS A RATHER DISORGANIZED APPEARANCE ON SATELLITE
IMAGES...AND CONSISTS PRIMARILY OF A RATHER SHAPELESS CLUSTER OF
DEEP CONVECTION WITH A FEW THUNDERSTORMS TO THE WEST-SOUTHWEST OF
THE CLUSTER.  THERE IS LITTLE...IF ANY...EVIDENCE OF BANDING
FEATURES.  AN ASCAT PASS FROM SEVERAL HOURS AGO INDICATED THAT THE
MAXIMUM WINDS REMAIN NEAR 45 KT.  HOWEVER...DATA FROM THIS PASS ALSO
CAST SOME DOUBT AS TO WHETHER THE SYSTEM HAS A CLOSED CIRCULATION
AT THIS TIME.  VISIBLE IMAGERY AND AN AIRCRAFT MISSION LATER TODAY
SHOULD GIVE MORE INFORMATION ON THE STATUS OF MARIA.  

NO CHANGE IS MADE TO THE INTENSITY FORECAST.  AN UPPER-LEVEL LOW OR
TROUGH TO THE NORTHWEST OF THE STORM HAS BEEN IMPARTING ABOUT 20 KT
OF SOUTH-SOUTHWESTERLY SHEAR OVER THE TROPICAL CYCLONE...AND
INHIBITING STRENGTHENING.  GLOBAL MODELS INDICATE THAT THIS
LOW/TROUGH WILL MOVE MORE OR LESS IN TANDEM WITH MARIA THROUGH
ABOUT 72 HOURS...AND CONTINUE TO PRODUCE SIGNIFICANT SHEAR ON THE
SYSTEM.  THE OFFICIAL FORECAST SHOWS NO STRENGTHENING THROUGH 72
HOURS FOLLOWED BY SOME INCREASE IN INTENSITY AS THE IMPACT OF THE
AFOREMENTIONED UPPER-LEVEL LOW IS EXPECTED TO LESSEN.  THE NHC WIND
SPEED FORECAST IS ROUGHLY BETWEEN THE LATEST LGEM GUIDANCE AND THE
INTENSITY MODEL CONSENSUS.

THE CENTER IS QUITE DIFFICULT TO FIND...BUT IT IS PRESUMED THAT
MARIA HAS BEEN MAINTAINING A MOTION OF 275/20. A CONTINUED WESTWARD
MOTION IS LIKELY FOR ANOTHER DAY OR SO AS THE STORM MOVES ON THE
SOUTHERN SIDE OF A SUBTROPICAL RIDGE. SOME DECELERATION IS
PREDICTED AS THE RIDGE WEAKENS A LITTLE WITH TIME. IN 48 TO 72
HOURS...MARIA SHOULD BE NEARING A WEAKNESS IN THE RIDGE AND TURN
WEST-NORTHWESTWARD. AS USUAL...THERE IS A FAIR AMOUNT OF
UNCERTAINTY IN THE TRACK 4 TO 5 DAYS FROM NOW. A BROAD 500 MB
TROUGH...MOVING OFF THE U.S EAST COAST...IS SHOWN BY THE GLOBAL
MODELS TO WEAKEN THE RIDGE ENOUGH TO CAUSE MARIA TO TURN
NORTHWESTWARD BY 96 HOURS. IF THE TROUGH TURNS OUT TO BE WEAKER
THAN CURRENTLY PREDICTED...IT COULD DELAY THE NORTHWESTWARD TURN.
THE OFFICIAL FORECAST IS VERY CLOSE TO THE PREVIOUS ONE AND ROUGHLY 
IN THE MIDDLE OF THE TRACK GUIDANCE ENVELOPE...BRACKETED BY THE
U.K. MET OFFICE MODEL ON THE LEFT AND BY THE GFS AND HWRF MODELS ON
THE RIGHT.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/0900Z 13.5N  48.2W   45 KT  50 MPH
 12H  08/1800Z 13.8N  51.2W   45 KT  50 MPH
 24H  09/0600Z 14.5N  54.7W   45 KT  50 MPH
 36H  09/1800Z 15.3N  57.8W   45 KT  50 MPH
 48H  10/0600Z 16.7N  60.8W   45 KT  50 MPH
 72H  11/0600Z 19.5N  65.5W   45 KT  50 MPH
 96H  12/0600Z 23.0N  69.0W   50 KT  60 MPH
120H  13/0600Z 26.0N  72.0W   60 KT  70 MPH
 
$$
FORECASTER PASCH
 

WTNT44 KNHC 081443
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 AM AST THU SEP 08 2011
 
MARIA IS MOVING VERY FAST...AT ABOUT 19-22 KNOTS...AND PROBABLY NO
LONGER HAS A CLOSED CIRCULATION. AN AIR FORCE RECONNAISSANCE PLANE
WILL CHECK IF THAT IS THE CASE LATER TODAY. VISIBLE SATELLITE
IMAGES SHOW THAT THE CLOUD PATTERN HAS BECOME DISORGANIZED AND
CONSISTS OF A TIGHT LOW-LEVEL SWIRL WITH SOME PATCHES OF DEEP
CONVECTION TO THE NORTH OF THE CENTER. IT IS ESTIMATED THAT THE
WINDS ASSOCIATED WITH THESE RAINBANDS ARE STILL 40 KNOTS AND THIS
IS THE INTENSITY ASSOCIATED WITH THE CYCLONE AT THIS TIME.
HOWEVER...EVEN IF MARIA DEGENERATES INTO A TROPICAL
WAVE...CONDITIONS REMAIN MARGINALLY FAVORABLE FOR THIS SYSTEM TO
REGENERATE AS IT SLOWS DOWN OVER THE NORTHEASTERN CARIBBEAN. MOST
OF THE GLOBAL MODELS ARE SHOWING AN UPPER LEVEL ENVIRONMENT NOT AS
HOSTILE AS THEY WERE INDICATING IN PREVIOUS RUNS...BUT NONE OF THE
GUIDANCE MODELS SHOW AN AGGRESSIVE STRENGTHENING THROUGH THE
CARIBBEAN. 

MARIA IS SOUTH OF A PERSISTENT AND LARGE SUBTROPICAL RIDGE THAT
EXTENDS WESTWARD ACROSS THE ATLANTIC. THIS STEERING PATTERN CALLS
FOR A WEST TO WEST-NORTHWEST TRACK OVER THE NEXT TWO TO THREE DAYS.
AFTER THAT...A WEAKER RIDGE NORTH OF THE CYCLONE IS EXPECTED TO
ALLOW A MORE NORTHWESTWARD TRACK AT A SOMEWHAT SLOWER FORWARD
SPEED. GUIDANCE IS IN VERY GOOD AGREEMENT...AND MOST OF THE MODELS
ARE CLUSTERED HAVING MARIA OVER OR JUST TO THE NORTH OF THE CENTRAL
BAHAMAS IN FIVE DAYS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/1500Z 13.0N  51.2W   40 KT  45 MPH
 12H  09/0000Z 13.0N  54.0W   45 KT  50 MPH
 24H  09/1200Z 13.8N  57.3W   45 KT  50 MPH
 36H  10/0000Z 14.5N  60.5W   45 KT  50 MPH
 48H  10/1200Z 16.0N  63.0W   45 KT  50 MPH
 72H  11/1200Z 19.5N  67.0W   45 KT  50 MPH
 96H  12/1200Z 22.5N  72.0W   50 KT  60 MPH
120H  13/1200Z 25.0N  75.0W   60 KT  70 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 082051
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 PM AST THU SEP 08 2011
 
THE CLOUD PATTERN HAS CONTINUED TO DETERIORATE.  MARIA CONSISTS OF A
TIGHT SWIRL OF LOW CLOUDS WITH SOME PATCHES OF CONVECTION MAINLY TO
THE NORTH OF THE CENTER. IN FACT...MARIA PERHAPS NO LONGER HAS A
CLOSED CIRCULATION...AND A RECONNAISSANCE PLANE IS CURRENTLY
APPROACHING THE CYCLONE TO DETERMINE IF THAT IS THE CASE. NOAA BUOY
41040 RECENTLY REPORTED 35 KNOTS TO THE NORTH OF THE CENTER...AND
THIS IS THE INITIAL INTENSITY ASSIGNED TO MARIA. GIVEN THE CURRENT
LACK OF ORGANIZATION...AN ENVIRONMENT NOT VERY FAVORABLE FOR
STRENGTHENING...AND THE FACT THAT THE LGEM...ECMWF AND HWRF MODELS
DO NOT STRENGTHEN MARIA IN THE NEXT COUPLE OF DAYS...THE OFFICIAL
FORECAST CALLS FOR SLIGHT WEAKENING.  THE NHC FORECAST DOES NOT
SHOW ANY INTENSIFICATION UNTIL THE SYSTEM IS LOCATED NORTH OF
PUERTO RICO AND HISPANIOLA IN ABOUT 72 HOURS. GIVEN THE
UNCERTAINTIES IN THE INTENSITY FORECAST...THE TROPICAL STORM WATCH
HAS BEEN KEPT FOR A LARGE PORTION OF THE LEEWARD ISLANDS. THESE
ISLANDS SHOULD BE READY TO QUICKLY ISSUE TROPICAL STORM
WARNINGS...IF NECESSARY.
 
THERE HAS BEEN NO CHANGE IN THE STEERING. MARIA CONTINUES TO MOVE
TOWARD THE WEST OR 275 DEGREES AT 18 KNOTS EMBEDDED WITHIN A STRONG
EASTERLY FLOW SOUTH OF THE SUBTROPICAL RIDGE WHICH EXTENDS WESTWARD
ACROSS THE ATLANTIC. GIVEN THIS PATTERN...THE OFFICIAL FORECAST
CALLS FOR A WEST TO WEST-NORTHWEST TRACK OVER THE NEXT TWO TO THREE
DAYS. A GRADUAL TURN TO THE NORTHWEST SHOULD BEGIN THEREAFTER...AS
THE CYCLONE APPROACHES THE WESTERN EDGE OF THE SUBTROPICAL RIDGE.
TRACK MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT...AND THE
OFFICIAL FORECAST IS IN THE MIDDLE OF THE RELATIVELY TIGHT GUIDANCE
ENVELOPE. THIS INCREASES THE CONFIDENCE IN THE TRACK FORECAST BUT
THE SAME CAN NOT BE SAID ABOUT THE INTENSITY FORECAST.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/2100Z 13.2N  52.7W   35 KT  40 MPH
 12H  09/0600Z 13.4N  55.3W   35 KT  40 MPH
 24H  09/1800Z 14.0N  58.5W   30 KT  35 MPH
 36H  10/0600Z 15.5N  61.5W   30 KT  35 MPH
 48H  10/1800Z 17.0N  63.5W   30 KT  35 MPH
 72H  11/1800Z 20.0N  68.0W   40 KT  45 MPH
 96H  12/1800Z 23.0N  72.0W   50 KT  60 MPH
120H  13/1800Z 25.5N  75.0W   60 KT  70 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 090310
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 PM AST THU SEP 08 2011

THE CLOUD PATTERN OF MARIA HAS STABILIZED THIS EVENING...ALBEIT IN A
RATHER DISORGANIZED CONDITION.  PATCHES OF CONVECTION ARE OCCURRING
OVER THE NORTHERN SEMICIRCLE OF A BROAD AREA OF CYCLONIC
ROTATION...WITH AN OVERALL INCREASE IN CONVECTIVE COVERAGE DURING
THE PAST SEVERAL HOURS.  DUE TO COMMUNICATIONS PROBLEMS...THE
AIRCRAFT THAT INVESTIGATED MARIA WAS UNABLE TO TRANSMIT A FULL DATA
SET.  THEREFORE...IT WAS NOT DETERMINED WITH CERTAINTY WHETHER A
WELL-DEFINED CLOSED CIRCULATION STILL EXISTED.  HOWEVER...THE PLANE
MEASURED A CENTRAL PRESSURE OF 1005 MB...SHOWING THAT AT THE VERY
LEAST A LOW PRESSURE CENTER STILL EXISTED.  BASED ON THIS...MARIA
IS MAINTAINED AS A TROPICAL CYCLONE.  THE INITIAL INTENSITY OF
35 KT IS BASED ON THE AIRCRAFT DATA AND RECENT BUOY REPORTS.

THE INITIAL MOTION IS 275/18.  THE DYNAMICAL MODELS FORECAST THE
CYCLONE TO TURN WEST-NORTHWESTWARD DURING THE NEXT 12-24 HOURS
TOWARD A WEAKNESS IN LOW/MID-LEVEL SUBTROPICAL RIDGE TO THE
NORTH...A WEAKNESS POSSIBLY CAUSED BY AN UPPER-LEVEL LOW SEEN IN
WATER VAPOR IMAGERY NEAR 23N61W.  WHILE THE NEW FORECAST TRACK
FOLLOWS THIS SCENARIO...THE CURRENT RAPID MOTION SUGGESTS THIS TURN
WILL BE MORE GRADUAL THAN THE MODEL GUIDANCE IS FORECASTING...AND
THUS THE FIRST PART OF THE NEW TRACK IS ON THE SOUTH SIDE OF THE
GUIDANCE ENVELOPE.  AFTER 24 HOURS...ALL OF THE GUIDANCE FORECASTS
MARIA TO MOVE WEST-NORTHWESTWARD TO NORTHWESTWARD TOWARD THE
WESTERN END OF THE SUBTROPICAL RIDGE AS A DEEP-LAYER TROUGH MOVES
THROUGH THE SOUTHEASTERN UNITED STATES.  AFTER SHIFTING TO THE LEFT
FOR THE PREVIOUS ADVISORY...THE GUIDANCE FOR THE POST-24 HOUR
PERIOD HAS SHIFTED TO THE RIGHT FOR THIS ADVISORY.  THE END OF THE
FORECAST TRACK WILL SHOW A SMALL RIGHT TURN...BUT STILL LIES TO THE
LEFT OF THE CENTER OF THE GUIDANCE ENVELOPE.  IT SHOULD BE NOTED
THAT THE UKMET AND ECMWF MODELS ARE STILL TO THE WEST OF THE NEW
FORECAST AT 120 HOURS.

THE INTENSITY GUIDANCE HAS BECOME A BIT MORE BULLISH THIS
EVENING...WITH THE SHIPS AND LGEM MODELS NO LONGER FORECASTING
MARIA TO WEAKEN TO A DEPRESSION.  INDEED...THE SHIPS MODEL SHOWS
THE VERTICAL WIND SHEAR DECREASING TO LESS THAN 10 KT DURING THE
NEXT 24 HOURS AND REMAINING THAT LIGHT THROUGH 96 HOURS.  GIVEN THE
PRESENCE OF THE UPPER-LEVEL LOW TO THE NORTHWEST AND THE FORECAST
UPPER-LEVEL WIND PATTERNS OF THE VARIOUS MODELS...THAT MIGHT BE A
BIT OPTIMISTIC.  THE NEW INTENSITY FORECAST NOW CALLS FOR MARIA TO
MAINTAIN A 35-KT INTENSITY FOR THE NEXT 24 HOURS...FOLLOWED BY
GRADUAL STRENGTHENING THROUGH THE REST OF THE FORECAST PERIOD.  THE
NEW INTENSITY FORECAST IS NEAR THE LOWER EDGE OF THE INTENSITY
FORECAST GUIDANCE.

THE CHANGE IN THE INTENSITY FORECAST FOR THE FIRST 24 HOURS REQUIRES
TROPICAL STORM WARNINGS FOR PORTIONS OF THE LEEWARD ISLANDS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0300Z 13.3N  54.6W   35 KT  40 MPH
 12H  09/1200Z 13.5N  57.2W   35 KT  40 MPH
 24H  10/0000Z 14.7N  60.4W   35 KT  40 MPH
 36H  10/1200Z 16.3N  62.8W   40 KT  45 MPH
 48H  11/0000Z 17.8N  65.2W   45 KT  50 MPH
 72H  12/0000Z 21.0N  69.5W   50 KT  60 MPH
 96H  13/0000Z 23.5N  73.0W   55 KT  65 MPH
120H  14/0000Z 26.0N  75.0W   60 KT  70 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 090850
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 AM AST FRI SEP 09 2011
 
THERE HAS BEEN AN INCREASE IN THE CONVECTION DURING THE PAST SEVERAL
HOURS BUT SATELLITE INTENSITY ESTIMATES HAVE NOT CHANGED. SURFACE
PRESSURES ARE FALLING...AS INDICATED BY BUOY 41101 WHICH RECENTLY
REPORTED A MINIMUM PRESSURE OF 1003.7 MB. THE INITIAL INTENSITY IS
KEPT AT 35 KNOTS AT THIS TIME...AND A RECONNAISSANCE PLANE WILL
CHECK MARIA AROUND 1200 UTC. THE UPPER-LEVEL WIND ENVIRONMENT IS
NOT AS HOSTILE AS IT WAS 12 TO 24 HOURS AGO...AND THE INTENSITY
GUIDANCE SHOWS SOME SLIGHT STRENGTHENING AS THE CYCLONE MOVES
ACROSS THE EXTREME NORTHEASTERN CARIBBEAN SEA...AND IT IS SOMEWHAT
MORE AGGRESSIVE BY THE END OF THE FORECAST PERIOD. THE NHC FORECAST
FOLLOWS SUCH GUIDANCE.
 
MARIA IS MOVING TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 17
KNOTS. THE LATEST TRACK GUIDANCE HAS SHIFTED TO THE RIGHT AS GLOBAL
MODELS NOW FORECAST A WEAKER SUBTROPICAL RIDGE TO THE NORTH OF THE
CYCLONE. ON THAT BASIS...THE OFFICIAL FORECAST HAS ALSO BEEN
SHIFTED TO THE NORTH BUT IT IS ON THE SOUTHERN EDGE OF THE NEW
GUIDANCE ENVELOPE IN CASE MODELS SHIFT BACK TO THE SOUTH IN THE
NEXT CYCLE.  GIVEN THE TRACK AND INTENSITY FORECAST...A TROPICAL
STORM WARNING HAS BEEN ISSUED FOR A LARGE PORTION OF THE
NORTHEASTERN CARIBBEAN ISLANDS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0900Z 13.8N  56.2W   35 KT  40 MPH
 12H  09/1800Z 14.5N  58.5W   35 KT  40 MPH
 24H  10/0600Z 16.0N  61.3W   35 KT  40 MPH
 36H  10/1800Z 17.5N  63.5W   40 KT  45 MPH
 48H  11/0600Z 19.0N  65.5W   45 KT  50 MPH
 72H  12/0600Z 22.0N  69.5W   55 KT  65 MPH
 96H  13/0600Z 24.0N  71.5W   65 KT  75 MPH
120H  14/0600Z 27.0N  73.5W   70 KT  80 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 091448
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 AM AST FRI SEP 09 2011
 
THERE HAS BEEN A SIGNIFICANT INCREASE IN DEEP CONVECTION OVERNIGHT
AND THIS MORNING IN ASSOCIATION WITH MARIA.  HOWEVER...THE OVERALL
ORGANIZATION OF THE CYCLONE DOES NOT APPEAR TO HAVE CHANGED VERY
MUCH.  THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT HAS FOUND
SOUTHWEST AND LIGHT WEST WINDS...BUT IT HAS NOT BEEN ABLE TO LOCATE
A WELL-DEFINED LOW-LEVEL CENTER.  HOWEVER...THERE ARE ENOUGH
FLIGHT-LEVEL WINDS INDICATING A BROAD CLOSED CIRCULATION THAT
JUSTIFIES MAINTAINING ADVISORIES ON THIS SYSTEM.
 
THE AIRCRAFT HAS MEASURED A PEAK FLIGHT-LEVEL WIND OF 42 KT TO THE
EAST OF THE CENTER...BUT HAS NOT YET SAMPLED THE NORTHEAST QUADRANT
WHERE THE STRONGEST WINDS ARE LIKELY OCCURRING.  THE INITIAL
INTENSITY...THEREFORE HAS BEEN RAISED TO 40 KT...BASED ON DVORAK
ESTIMATES OF 45 KT AND THE RECENT INCREASE IN DEEP CONVECTION.  THE
UPPER-LEVEL PATTERN AHEAD OF MARIA DOES NOT APPEAR TO BE VERY
CONDUCIVE FOR SIGNIFICANT STRENGTHENING.  AN UPPER-LEVEL LOW
LOCATED TO THE NORTH OF THE LEEWARD ISLANDS IS EXPECTED TO PRODUCE
MODERATE WEST TO SOUTHWEST SHEAR OVER THE CYCLONE DURING THE NEXT
2-3 DAYS...AND THE OFFICIAL FORECAST ONLY CALLS FOR SLIGHT
STRENGTHENING DURING THAT TIME.  LATER IN THE PERIOD THE
UPPER-LEVEL ENVIRONMENT IS FORECAST TO BECOME MORE CONDUCIVE AND
THE NHC FORECAST CALLS FOR STRENGTHENING...BUT NOT QUITE AS MUCH
AS SHOWN BY MOST OF THE GUIDANCE.

THE BEST ESTIMATE OF THE INITIAL MOTION IS 285/15. MARIA IS EXPECTED
TO CONTINUE MOVING WEST-NORTHWESTWARD TO THE SOUTH OF A SUBTROPICAL
RIDGE OVER THE CENTRAL AND WESTERN ATLANTIC.  IN ABOUT 72 HOURS...
THE WESTERN PORTION OF THE RIDGE IS FORECAST TO WEAKEN AS A TROUGH
MOVES INTO THE SOUTHEASTERN UNITED STATES. THIS SHOULD RESULT IN A
TURN TOWARD THE NORTHWEST AND NORTH NEAR THE END OF THE FORECAST
PERIOD.  HOWEVER...IT SHOULD BE NOTED THAT THE ECMWF MODEL DEPICTS A
WEAKER CYCLONE THAT CONTINUES MORE WESTWARD.  THE UPDATED NHC
FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS BETWEEN THE
GFS..WHICH TURNS MARIA NORTHWARD IN 4-5 DAYS...AND THE
AFOREMENTIONED ECMWF. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/1500Z 14.2N  57.5W   40 KT  45 MPH
 12H  10/0000Z 15.1N  59.9W   45 KT  50 MPH
 24H  10/1200Z 16.5N  62.4W   45 KT  50 MPH
 36H  11/0000Z 17.9N  64.5W   45 KT  50 MPH
 48H  11/1200Z 19.3N  66.5W   50 KT  60 MPH
 72H  12/1200Z 22.0N  69.8W   55 KT  65 MPH
 96H  13/1200Z 24.0N  72.0W   65 KT  75 MPH
120H  14/1200Z 27.5N  73.5W   70 KT  80 MPH
 
$$
FORECASTER BROWN
 

WTNT44 KNHC 092039
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 PM AST FRI SEP 09 2011

THERE HAS BEEN LITTLE CHANGE TO THE ORGANIZATION OF MARIA SINCE THIS
MORNING. VISIBLE IMAGERY DURING THE EARLY AFTERNOON REVEALED
SEVERAL BANDS OF DEEP CONVECTION OVER THE NORTH AND EAST PORTIONS
OF THE CIRCULATION...BUT RECENT INFRARED IMAGERY AND RADAR DATA FROM
GUADELOUPE SHOW WARMING CLOUD TOPS AND SOME WEAKENING OF THE
CONVECTION.  BEFORE DEPARTING MARIA...THE AIR FORCE RECONNAISSANCE
AIRCRAFT FOUND PEAK 850-MB FLIGHT-LEVEL WINDS OF 47 KT...WHICH
SUPPORT AN INITIAL INTENSITY OF 40 KT. THE GLOBAL MODELS NOW
INDICATE THAT THE UPPER-LEVEL LOW TO THE NORTH OF THE LEEWARD
ISLANDS WILL WEAKEN AND MOVE NORTHWESTWARD DURING THE NEXT 36
HOURS...ALLOWING FOR A MORE FAVORABLE UPPER-LEVEL WIND PATTERN. 
HOWEVER...THE CURRENT LACK OF INNER-CORE STRUCTURE SUGGESTS 
THAT STRENGTHENING IS LIKELY TO BE MORE GRADUAL THAN INDICATED BY
SOME OF THE INTENSITY GUIDANCE. THE NEW OFFICIAL FORECAST IS 
ABOVE THE PREVIOUS ADVISORY...BUT LOWER THAN THE INTENSITY
CONSENSUS DURING THE FIRST COUPLE OF DAYS. AFTER 48 HOURS...THE
ENVIRONMENT IS EXPECTED TO BE EVEN MORE CONDUCIVE FOR
INTENSIFICATION. 

IT APPEARS THAT MARIA HAS SLOWED DOWN TODAY. SURFACE OBSERVATIONS
SUGGEST THAT THE LOW-LEVEL CENTER...SUCH AS IT IS...IS LOCATED TO
THE SOUTHWEST OF THE MID-LEVEL CENTER SEEN IN VISIBLE SATELLITE
IMAGERY. IT WOULD NOT BE SURPRISING IF THE SURFACE CENTER REFORMS
CLOSER TO THE MID-LEVEL CENTER OVERNIGHT OR ON SATURDAY. IN FACT...
THIS MAY BE WHY THE GLOBAL MODELS SHOW A TRACK FARTHER NORTH ACROSS
THE LEEWARD ISLANDS. PARTLY FOR THIS REASON...THE NEW TRACK HAS
BEEN ADJUSTED A LITTLE NORTH OF THE PREVIOUS ADVISORY DURING THE
FIRST 24 TO 36 HOURS. AFTER THAT...THE TRACK GUIDANCE HAS COME INTO
BETTER AGREEMENT SHOWING MARIA TURNING NORTHWESTWARD AND THEN
NORTHWARD AS A TROUGH OVER THE SOUTHEASTERN UNITED STATES WEAKENS
THE WESTERN PORTION OF THE SUBTROPICAL RIDGE. THE OFFICIAL FORECAST
AS BEEN SHIFTED EASTWARD AT DAYS 4 AND 5...CLOSER TO THE
MULTI-MODEL CONSENSUS.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/2100Z 14.8N  58.6W   40 KT  45 MPH
 12H  10/0600Z 15.8N  60.6W   45 KT  50 MPH
 24H  10/1800Z 17.2N  62.8W   50 KT  60 MPH
 36H  11/0600Z 18.7N  64.9W   55 KT  65 MPH
 48H  11/1800Z 20.0N  66.6W   60 KT  70 MPH
 72H  12/1800Z 22.7N  69.5W   70 KT  80 MPH
 96H  13/1800Z 25.5N  71.5W   80 KT  90 MPH
120H  14/1800Z 31.0N  71.0W   90 KT 105 MPH
 
$$
FORECASTER BROWN
 

WTNT44 KNHC 100250
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 PM AST FRI SEP 09 2011
 
MARIA HAS DEVELOPED A BAND OF STRONG CONVECTION OVER THE EASTERN
SEMICIRCLE THIS EVENING...AND THERE HAS BEEN EVIDENCE OF CYCLONIC
ROTATION IN RADAR DISPLAYS FROM BARBADOS...MARTINIQUE...AND
GUADELOUPE.  HOWEVER...THIS HAS NOT YET TRANSLATED INTO ANY
INCREASED ORGANIZATION IN THE WIND FIELD ACCORDING TO DATA FROM AN
AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT.  THE AIRCRAFT DID NOT
FIND STRONG WINDS DURING ITS MISSION...ALTHOUGH IT LIKELY DID NOT
SAMPLE FAR ENOUGH FROM THE CENTER TO MEASURE THE STRONG WINDS IN
THE NORTHEASTERN QUADRANT.  THE INITIAL INTENSITY REMAINS 40 KT
BASED ON RECENT OBSERVATIONS FROM A FRENCH BUOY EAST OF THE CENTER
AND THE LIKELIHOOD OF STRONGER WINDS FARTHER NORTH.
 
THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 295/12.  MARIA IS ON THE
SOUTH SIDE OF A LOW/MID-LEVEL SUBTROPICAL RIDGE...WHILE WATER VAPOR
IMAGERY SHOWS AN UPPER-LEVEL LOW NORTH-NORTHWEST OF THE STORM NEAR
24N63W.  THE DYNAMICAL MODELS FORECAST THE RIDGE TO PERSIST FOR
48 HOURS OR SO...THEN WEAKEN AS A DEEP-LAYER TROUGH MOVES EASTWARD
ACROSS THE SOUTHEASTERN UNITED STATES INTO THE SOUTHWESTERN
ATLANTIC.  THE TRACK MODEL GUIDANCE IS IN EXCELLENT AGREEMENT THAT
MARIA WILL MOVE GENERALLY NORTHWESTWARD FOR THE NEXT 48 HOURS...
THEN GRADUALLY TURN NORTHWARD AND NORTH-NORTHEASTWARD IN RESPONSE
TO THE APPROACHING TROUGH.  FOR THE FIRST 72 HOURS...THE NEW
FORECAST TRACK IS ALMOST IDENTICAL TO THE PREVIOUS TRACK AND IS
DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE.  AFTER THAT...THE TRACK
IS SHIFTED TO THE EAST OF THE PREVIOUS TRACK AND LIES A LITTLE TO
THE LEFT OF...AND SLOWER...THAN THE MIDDLE OF THE GUIDANCE
ENVELOPE.
 
MARIA HAS DEVELOPED A GOOD UPPER-LEVEL OUTFLOW PATTERN...ALTHOUGH
THERE MAY BE SOME RESIDUAL SHEAR UNDERCUTTING THE OUTFLOW.  THE
INTENSITY GUIDANCE UNANIMOUSLY FORECASTS THE STORM TO STRENGTHEN...
ALTHOUGH THE CURRENT STATE OF DISORGANIZATION SUGGESTS THAT THE
INITIAL STRENGTHENING SHOULD BE SLOW.  THE NEW INTENSITY FORECAST
CALLS FOR A SLOWER DEVELOPMENT RATE DURING THE FIRST 24-36 HOURS...
THEN CATCHES UP WITH THE PREVIOUS FORECAST.  LATER IN THE FORECAST
PERIOD...MARIA IS FORECAST TO COME CLOSE TO THE AFOREMENTIONED
UPPER-LEVEL LOW.  THE DYNAMICAL MODELS HAVE A VARIETY OF SOLUTIONS
FOR HOW THE TWO SYSTEMS WILL INTERACT...ALTHOUGH NONE OF THE
GUIDANCE SHOW MARIA WEAKENING DUE TO THE INTERACTION.  THE LATTER
PART OF THE INTENSITY FORECAST IS IDENTICAL TO THE PREVIOUS
FORECAST AND IS IN BEST AGREEMENT WITH A BLEND OF THE SHIPS AND
LGEM MODELS.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/0300Z 15.1N  59.5W   40 KT  45 MPH
 12H  10/1200Z 16.2N  61.5W   40 KT  45 MPH
 24H  11/0000Z 17.8N  63.7W   45 KT  50 MPH
 36H  11/1200Z 19.3N  65.8W   50 KT  60 MPH
 48H  12/0000Z 20.8N  67.5W   60 KT  70 MPH
 72H  13/0000Z 23.5N  70.0W   70 KT  80 MPH
 96H  14/0000Z 27.5N  71.0W   80 KT  90 MPH
120H  15/0000Z 34.0N  69.0W   90 KT 105 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 100845
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  15
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 AM AST SAT SEP 10 2011
 
MARIA LOOKS DISORGANIZED ON SATELLITE IMAGERY AND IT APPEARS
THAT IT DOES NOT HAVE A WELL-DEFINED CLOSED CIRCULATION AT THE
SURFACE. HOWEVER A RECONNAISSANCE PLANE REPORTED WINDS OF NEAR 43
KNOTS TO THE NORTH OF THE ALLEDGED CENTER ON ITS WAY TO THE
BASE. IN ADDITION...SURFACE OBSERVATIONS FROM THE LESSER ANTILLES
AND THE GUADELOUPE RADAR STILL SHOW A BROAD CIRCULATION. I AM NOT
READY TO WRITE THIS ONE OFF YET AND MARIA IS KEPT AS A 40-KNOT
TROPICAL STORM IN THIS ADVISORY. GIVEN THE CURRENT UNCERTAINTY IN
THE STATUS OF MARIA...I PROPOSE NOT TO CHANGE ANY OF THE TROPICAL
STORM WARNINGS AT THIS TIME.
 
EARLY VISIBLE SATELLITE IMAGES AND ANOTHER RECONNAISSANCE PLANE IN
THE MORNING WILL HELP US TO DETERMINE IF MARIA IS STILL A TROPICAL
CYCLONE OR NOT.  EVEN IF THE PLANE FINDS AN OPEN TROUGH...THE UPPER
LEVEL ENVIRONMENT FAVORS REGENERATION AND STRENGHTENING.  THIS IS
SUPPORTED BY MOST OF THE INTENISTY GUIDANCE. IN FACT...EVEN THE
HWRF HAS BECOME MORE AGRESSIVE MAKING MARIA A HURRICANE IN ABOUT 2
TO 3 DAYS...AND SO DOES THE OFFICIAL FORECAST. THE ECMWF IS NOT VERY
ENTHUSIASTIC WITH MARIA.
 
BECAUSE THE CENTER IS DIFFICULT TO LOCATE THE INITIAL MOTION IS
HIGHLY UNCERTAIN. IT APPEARS THAT MARIA IS NOW MOVING TOWARD THE
NORTHWEST OR 315 DEGREES AT 11 KNOTS. THE CYCLONE WILL BE REACHING
THE SOUTHWEST SIDE OF THE SUBTROPICAL IN A DAY...SO A TURN MORE TO
THE NORTHWEST AND NORTH IS FORECAST. TRACK GUIDANCE IS IN VERY GOOD
AGREEMENT INCREASING THE CONFIDENCE IN THE TRACK FORECAST.  THE
REAL CHALLENGE HERE IS THE INTENSITY FORECAST FOR THE NEXT DAY OR
SO AS THE CYCLONE MOVES OVER THE NORTHEASTERN CARIBBEAN SEA.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/0900Z 16.0N  60.2W   40 KT  45 MPH
 12H  10/1800Z 17.0N  61.5W   40 KT  45 MPH
 24H  11/0600Z 18.5N  64.0W   45 KT  50 MPH
 36H  11/1800Z 20.0N  66.0W   50 KT  60 MPH
 48H  12/0600Z 21.5N  67.5W   60 KT  70 MPH
 72H  13/0600Z 23.5N  69.5W   70 KT  80 MPH
 96H  14/0600Z 27.5N  70.5W   80 KT  90 MPH
120H  15/0600Z 34.0N  68.5W   80 KT  90 MPH
 
$$
FORECASTER AVILA
 

WTNT44 KNHC 101458
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
1100 AM AST SAT SEP 10 2011
 
MARIA HAS BECOME SIGNIFICANTLY LESS ORGANIZED DURING THE LAST
12-18 HOURS.  THE LARGE UPPER-LEVEL LOW AND TROUGH LOCATED NORTH
OF PUERTO RICO IS PRODUCING MODERATE WEST TO NORTHWESTERLY SHEAR
OVER THE CYCLONE.  SATELLITE IMAGERY...SURFACE OBSERVATIONS...AND
DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT THE WEAK CIRCULATION CENTER IS APPROACHING ANTIGUA.  THE
CIRCULATION IS NOT VERY WELL DEFINED...BUT HAS ENOUGH DEFINITION TO
MAINTAIN ADVISORIES FOR NOW.  THE INITIAL INTENSITY IS GENEROUSLY
KEPT AT 35 KT...WITH THE ASSUMPTION THAT TROPICAL-STORM-FORCE WINDS
ARE OCCURRING IN THE CONVECTION WELL TO THE NORTHEAST OF THE
CENTER.  BECAUSE THESE WINDS ARE SO FAR REMOVED FROM THE
CENTER...AND NOT EXPECTED TO IMPACT THE LESSER ANTILLES...ALL
TROPICAL STORM WARNINGS HAVE BEEN DISCONTINUED.
 
MODEL GUIDANCE SUGGESTS THAT SHEAR WILL CONTINUE OVER THE CYCLONE
DURING THE NEXT COUPLE OF DAYS.  THE NEW INTENSITY FORECAST
THEREFORE CALLS FOR CONTINUED WEAKENING DURING THE NEXT DAY OR
TWO.  IF MARIA SURVIVES AS A TROPICAL CYCLONE...THE UPPER-LEVEL
ENVIRONMENT COULD BECOME A LITTLE MORE FAVORABLE WHEN IT IS
FORECAST TO BE EAST OF THE BAHAMAS.  THE OFFICIAL FORECAST REFLECTS
RESTRENGTHENING...BUT GIVEN THE CURRENT LACK OF STRUCTURE OF THE
CYCLONE...IS MUCH LOWER THAN THE OBJECTIVE GUIDANCE.
 
THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON A NORTHWESTWARD
MOTION DURING THE NEXT COUPLE OF DAYS AROUND THE WESTERN SIDE OF THE
SUBTROPICAL RIDGE.  A TROUGH MOVING ACROSS THE SOUTHEASTERN UNITED
STATES IN 2-3 DAYS IS FORECAST TO TURN MARIA NORTHWARD...THEN
NORTH-NORTHEASTWARD LATER IN THE FORECAST PERIOD.  THE NEW TRACK
FORECAST IS A LITTLE TO THE RIGHT OF THE PREVIOUS ADVISORY DURING
THE FIRST COUPLE OF DAYS...BUT THE REMAINDER OF THE TRACK IS
ESSENTIALLY AN UPDATE OF THE PREVIOUS NHC FORECAST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/1500Z 17.3N  61.5W   35 KT  40 MPH
 12H  11/0000Z 18.4N  63.2W   30 KT  35 MPH
 24H  11/1200Z 19.9N  64.9W   30 KT  35 MPH
 36H  12/0000Z 21.4N  66.5W   30 KT  35 MPH
 48H  12/1200Z 22.7N  68.0W   35 KT  40 MPH
 72H  13/1200Z 24.9N  70.2W   45 KT  50 MPH
 96H  14/1200Z 29.0N  71.0W   55 KT  65 MPH
120H  15/1200Z 36.0N  68.0W   55 KT  65 MPH
 
$$
FORECASTER BROWN/FRANKLIN
 

WTNT44 KNHC 102033
TCDAT4
 
TROPICAL STORM MARIA DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142011
500 PM AST SAT SEP 10 2011
 
MARIA HAS CHANGED LITTLE IN ORGANIZATION DURING THE DAY.  THE
CENTER...SUCH AS IT IS...IS EXPOSED TO THE SOUTHWEST OF AN AREA
OF DEEP CONVECTION THAT IS PASSING JUST NORTH OF THE NORTHEASTERN
LEEWARD ISLANDS.  THE EARLIER RECONNAISSANCE AIRCRAFT FLEW THROUGH
THE NORTHEASTERN QUADRANT JUST AFTER THE RELEASE OF THE PREVIOUS
ADVISORY AND FOUND WINDS TO SUPPORT A SLIGHTLY HIGHER INTENSITY OF
40 KT. GLOBAL MODEL AND SHIPS MODEL GUIDANCE INDICATE THAT THE
MODERATE WESTERLY SHEAR SHOULD CONTINUE DURING THE NEXT DAY OR SO.
MOST OF THE GLOBAL MODELS THEN SHOW THE UPPER-LEVEL LOW/TROUGH TO
THE NORTHWEST OF MARIA WEAKENING IN A COUPLE OF DAYS...WHICH WOULD
RESULT IN A MORE FAVORABLE UPPER-LEVEL WIND PATTERN FOR
STRENGTHENING. HOWEVER...THE ECMWF MODEL DOES NOT WEAKEN THE
UPPER-LEVEL TROUGH AS MUCH AND KEEPS SOUTHWESTERLY SHEAR OVER THE
CYCLONE. THE NEW INTENSITY FORECAST...LIKE THE PREVIOUS ONE...SHOWS
NO CHANGE IN WIND SPEED DURING THE FIRST 36 HOURS. AFTER THAT TIME
THE NHC FORECAST INDICATES SOME STRENGTHENING...BUT IT REMAINS NEAR
THE LOW END OF THE INTENSITY GUIDANCE...IN AGREEMENT WITH THE LGEM
MODEL.
 
THE TRACK FORECAST REASONING HAS NOT CHANGED.  MARIA IS EXPECTED TO
MOVE WEST-NORTHWESTWARD AROUND THE WESTERN SIDE OF A MID- TO
UPPER-LEVEL RIDGE OVER THE CENTRAL ATLANTIC.  IN 2 TO 3 DAYS MARIA
IS FORECAST TO TURN NORTHWARD AND THEN NORTHEASTWARD AHEAD OF A
TROUGH APPROACHING THE SOUTHEAST UNITED STATES COAST. THE TRACK 
GUIDANCE REMAINS IN GOOD AGREEMENT...BUT THERE ARE SOME SPEED
DIFFERENCES...WITH THE AFOREMENTIONED ECMWF MOVING A WEAKER MARIA
MORE SLOWLY TO THE NORTH.  THE NHC FORECAST IS NEAR THE MIDDLE OF
THE GUIDANCE ENVELOPE AND VERY CLOSE TO THE PREVIOUS ADVISORY.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/2100Z 17.9N  62.4W   40 KT  45 MPH
 12H  11/0600Z 19.0N  63.8W   40 KT  45 MPH
 24H  11/1800Z 20.6N  65.4W   40 KT  45 MPH
 36H  12/0600Z 21.9N  67.0W   40 KT  45 MPH
 48H  12/1800Z 22.9N  68.2W   45 KT  50 MPH
 72H  13/1800Z 25.5N  70.1W   50 KT  60 MPH
 96H  14/1800Z 30.0N  70.0W   60 KT  70 MPH
120H  15/1800Z 37.5N  65.5W   60 KT  70 MPH
 
$$
FORECASTER BROWN
 

