WTNT42 KNHC 110255
TCDAT2
SUBTROPICAL STORM OLGA DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
1100 PM EDT MON DEC 10 2007
 
SATELLITE IMAGERY AND RADAR DATA FROM THE SAN JUAN WSR-88D INDICATE
THAT THE LOW PRESSURE SYSTEM CENTERED NEAR THE VIRGIN ISLANDS AND
PUERTO RICO HAS ACQUIRED A WELL-DEFINED...THOUGH BROAD...SURFACE
CIRCULATION AND ORGANIZED CONVECTION NOT FAR FROM THE CENTER.  DUE
TO THE PRESENCE OF AN UPPER-LEVEL LOW JUST SOUTH OF THE VIRGIN
ISLANDS...IT IS BEING DESIGNATED A SUBTROPICAL CYCLONE.  NOAA BUOY
41043 NORTH OF THE CENTER HAS TWICE REPORTED 1-MIN AVERAGE WINDS OF
33 KT AT AN ELEVATION OF 5 METERS...WHICH SUGGESTS TROPICAL-STORM
FORCE WINDS ARE OCCURRING AT THE STANDARD SURFACE ELEVATION OF 10
METERS.  BASED ON ALL THIS...THE SYSTEM IS UPGRADED TO SUBTROPICAL
STORM OLGA.  THE INITIAL INTENSITY OF 35 KT IS IN AGREEMENT WITH
SUBTROPICAL INTENSITY ESTIMATES OF 35-40 KT FROM TAFB.

THE INITIAL MOTION IS 275/13.  OLGA IS ON THE SOUTH SIDE OF
A STRONG LOW/MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC...FLORIDA...
AND THE EASTERN GULF OF MEXICO.  THIS RIDGE SHOULD PERSIST FOR THE
NEXT SEVERAL DAYS AND STEER OLGA ON A GENERAL WESTWARD TO WEST-
SOUTHWESTWARD TRACK.  THE FORECAST TRACK FOLLOWS THIS SCENARIO AND
IS DOWN THE MIDDLE OF THE SUITE OF DYNAMICAL MODELS.

OLGA CURRENTLY HAS GOOD OUTFLOW OVER THE NORTHWESTERN SEMICIRCLE...
WITH OUTFLOW AND CONVECTION IN THE SOUTHEASTERN SEMICIRCLE
SUPPRESSED BY THE UPPER-LEVEL LOW.  IN THE SHORT-TERM...THIS
PATTERN IS FAVORABLE FOR SOME STRENGTHENING...AND THE INTENSITY
FORECAST CALLS FOR MODEST INTENSIFICATION BEFORE THE CENTER REACHES
THE DOMINICAN REPUBLIC ON TUESDAY.  AFTER THAT...THE LARGE-SCALE
MODELS FORECAST STRONG WESTERLY VERTICAL WIND SHEAR TO DEVELOP
ALONG THE FORECAST TRACK.  THAT...COMBINED WITH THE LIKELY
DISRUPTION OF THE CIRCULATION BY PASSAGE OVER HISPANIOLA...SHOULD
CAUSE WEAKENING.  THE LARGE-SCALE MODELS FORECAST OLGA TO WEAKEN TO
AN INVERTED TROUGH BY 36-48 HR... WHILE THE SHIPS MODEL FORECASTS
DISSIPATION IN 60 HR.  BASED ON THIS...THE INTENSITY FORECAST CALLS
FOR OLGA TO SURVIVE FOR 48 HR BEFORE DISSIPATING.

AFTER COORDINATION WITH THE WFO SAN JUAN...IT WAS DECIDED THAT
WATCHES AND WARNINGS WERE NOT NEEDED FOR PUERTO RICO SINCE THE
TROPICAL STORM-FORCE WINDS ARE CURRENTLY OVER WATER WELL TO THE
NORTH AND WEST OF THE CENTER.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/0300Z 18.5N  65.3W    35 KT
 12HR VT     11/1200Z 18.5N  67.6W    40 KT
 24HR VT     12/0000Z 18.4N  70.6W    30 KT...INLAND
 36HR VT     12/1200Z 18.0N  73.8W    25 KT...OVER WATER
 48HR VT     13/0000Z 17.8N  76.9W    25 KT...DISSIPATING
 72HR VT     14/0000Z...DISSIPATED
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 110842
TCDAT2
SUBTROPICAL STORM OLGA DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
400 AM EST TUE DEC 11 2007
 
WSR-88D RADAR IMAGERY FROM SAN JUAN PUERTO RICO REVEALS THAT THE
CENTER OF OLGA HAS BEEN MOVING ALONG THE NORTHERN COAST OF THAT
ISLAND FOR THE PAST SEVERAL HOURS...AT A WESTWARD HEADING OF 270
DEGREES AT ABOUT 15 KT.  OLGA SEEMS TO HAVE BEGUN A GRADUAL
DECLINE...GIVEN A SLIGHT THINNING OF THE RAIN SHIELD IN THE RADAR
IMAGERY...WARMING CLOUD TOPS IN GOES INFRARED IMAGERY...AND A
DECREASE IN LONG-RANGE LIGHTNING RETURNS.  THE INITIAL INTENSITY
REMAINS 40 KT...HOWEVER...BASED ON THE SEVERAL OBSERVATIONS DURING
THE PAST FEW HOURS OF ABOUT 40 KT FROM A FEW SHIPS AND NOAA BUOY
41043.  THIS ESTIMATE IS ALSO CONSISTENT WITH THE MAXIMUM WINDS
FROM A FORTUITOUS ASCAT OVERPASS BACK AT 0206Z.  FOR NOW WE WILL
RETAIN THE SUBTROPICAL DESIGNATION FOR OLGA SINCE WATER VAPOR
IMAGERY SUGGESTS THAT AN ELONGATING UPPER-LEVEL LOW IS SITUATED
ABOVE THE LOW-LEVEL CENTER.  THIS FEATURE APPEARS TO BE
WEAKENING...AND GLOBAL MODELS FORECAST THAT IT WILL DISSIPATE LATER
TODAY...SO OLGA COULD SOON MAKE THE TRANSITION TO A TROPICAL
CYCLONE.

THE TRACK FORECAST IS GENERALLY STRAIGHTFORWARD...SINCE A LOW- TO
MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC WILL LIKELY STEER OLGA ON
A CONTINUED WESTWARD PATH OVER HISPANIOLA AND INTO THE NORTHERN
CARIBBEAN SEA.  THE EXACT PATH OF THE CENTER ITSELF IS OF
RELATIVELY LITTLE CONSEQUENCE IN THIS CASE...SINCE MOST OF THE
HEAVY RAINS AND STRONGEST WINDS ARE WELL REMOVED FROM THE CENTER. 
DUE TO OLGA'S DEGRADED SATELLITE APPEARANCE...SIGNIFICANT
STRENGTHENING PRIOR TO REACHING HISPANIOLA APPEARS UNLIKELY...AND
HEAVY RAINFALL REMAINS THE PRIMARY HAZARD FROM THIS SYSTEM. 
WEAKENING IS THEN FORECAST AS OLGA MOVES ACROSS HISPANIOLA DURING
THE NEXT 24 HOURS...AND AN INCREASE IN WIND SHEAR SHOULD PROHIBIT
RESTRENGTHENING OVER THE WARM WATERS OF THE CARIBBEAN SEA.  IF
OLGA...OR ITS REMNANT LOW...SURVIVES THE NEXT THREE DAYS...THE
MODELS SUGGEST THAT SOME REDEVELOPMENT COULD OCCUR OVER THE WESTERN
CARIBBEAN WHERE UPPER-LEVEL WINDS ARE FORECAST TO LESSEN.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/0900Z 18.5N  67.0W    40 KT
 12HR VT     11/1800Z 18.5N  69.4W    40 KT...INLAND
 24HR VT     12/0600Z 18.5N  72.8W    30 KT...NEAR COAST OF HAITI
 36HR VT     12/1800Z 18.5N  76.1W    30 KT...DISSIPATING
 48HR VT     13/0600Z 18.5N  79.4W    25 KT...REMNANT LOW
 72HR VT     14/0600Z 18.5N  83.5W    25 KT...REMNANT LOW
 
$$
FORECASTER KNABB/MAINELLI
 

WTNT42 KNHC 111450
TCDAT2
SUBTROPICAL STORM OLGA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
1000 AM EST TUE DEC 11 2007
 
RECENT BUOY...QUIKSCAT...AND SHIP REPORTS INDICATE THAT OLGA'S PEAK
WINDS ARE NEAR 40 KT...AND EXTEND FARTHER AWAY FROM THE CENTER THAN
EARLIER ESTIMATED.  THE STRUCTURE OF OLGA...WITH ITS STRONGEST
WINDS LOCATED STILL 100-200 NMI FROM CENTER...CONTINUES TO BE
CONSISTENT WITH THAT OF A SUBTROPICAL CYCLONE.
 
THE INITIAL MOTION ESTIMATE IS 260/13...ALTHOUGH THE CENTER HAS
MOVED LITTLE OVER THE PAST FEW HOURS. A LOW- TO MID-LEVEL RIDGE
OVER THE WESTERN ATLANTIC IS EXPECTED TO KEEP OLGA ON A BASIC
WESTWARD PATH NEAR THE SOUTH COAST OF HISPANIOLA AND INTO THE
NORTHWESTERN CARIBBEAN SEA...AND MODEL GUIDANCE IS IN RELATIVELY
GOOD AGREEMENT ON THIS SCENARIO. THE OFFICIAL FORECAST LIES ALONG
THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE AND IS IN BEST AGREEMENT
WITH THE GFS.
 
ALTHOUGH THE CIRCULATION OF OLGA WILL BE INTERACTING WITH THE RUGGED
TERRAIN OF HISPANIOLA...THE PRESSURE GRADIENT AWAY FROM THE
CENTER...WHERE THE STRONGEST WINDS ARE LOCATED...WILL BE SLOW TO
DIMINISH.  THE UPPER-LEVEL TROUGH CURRENTLY OVER THE CYCLONE IS
FORECAST BY ALL THE GLOBAL MODELS TO WEAKEN AND BE REPLACED BY
STRONG NORTHWESTERLY SHEAR OVER THE NEXT 24-36 HOURS OR SO...AND
WHEN THIS HAPPENS OLGA SHOULD DEGENERATE TO A REMNANT LOW.
 
THE PRIMARY THREAT FROM OLGA IS HEAVY RAINFALL...WHICH IS
ALREADY PRODUCING LIFE-THREATENING MUD SLIDES IN PUERTO RICO.
THESE RAINS WILL BE SPREADING ACROSS HISPANIOLA OVER THE NEXT 24
HOURS...WHERE FLASH FLOODS AND MUD SLIDES ARE ALSO LIKELY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/1500Z 18.1N  68.0W    40 KT
 12HR VT     12/0000Z 18.0N  70.5W    35 KT
 24HR VT     12/1200Z 18.1N  74.0W    30 KT
 36HR VT     13/0000Z 18.2N  77.4W    30 KT...REMNANT LOW
 48HR VT     13/1200Z 18.2N  80.5W    25 KT...REMNANT LOW
 72HR VT     14/1200Z 18.0N  85.0W    25 KT...REMNANT LOW
 96HR VT     15/1200Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 

WTNT42 KNHC 112033
TCDAT2
SUBTROPICAL STORM OLGA DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
400 PM EST TUE DEC 11 2007
 
AN ASCAT PASS FROM LATE THIS MORNING SUGGESTS THAT THE WINDS TO THE
NORTH OF THE CENTER MAY HAVE DECREASED A LITTLE...BUT A
RECONNAISSANCE AIRCRAFT WILL REACH THE AREA SHORTLY...AND I WOULD
PREFER TO WAIT FOR THEIR REPORTS BEFORE ADJUSTING THE ESTIMATED
INTENSITY.  GRAND TURK ISLAND RECENTLY REPORTED A SUSTAINED WIND OF
31 KT.  THERE HAS BEEN AN INCREASE IN CONVECTION NEAR THE
CENTER OVER THE PAST COUPLE OF HOURS...AND THE ASCAT DATA ALSO
SUGGEST THAT THE RADIUS OF MAXIMUM WINDS MAY BE DECREASING.  IF
THIS IS CONFIRMED BY THE AIRCRAFT...OLGA COULD BE CLASSIFIED AS A
TROPICAL CYCLONE THIS EVENING.
 
THE CENTER OF OLGA MADE LANDFALL IN THE DOMINICAN REPUBLIC JUST TO
THE SOUTH OF PUNTA CANA AROUND 18Z.  THE MOTION OF THE CENTER HAS
BEEN ERRATIC...BUT OVERALL IS ESTIMATED TO BE 270/11.  THERE HAS
BEEN LITTLE CHANGE TO THE SYNOPTIC REASONING...WHICH CALLS FOR OLGA
TO BE STEERED BASICALLY WESTWARD TO THE SOUTH OF A LOW- TO
MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC.  AFTER 48 HOURS...OLGA
WILL BE ROUNDING THE PERIPHERY OF THIS RIDGE...BUT THERE IS LIKELY
TO BE LITTLE LEFT OF THE CYCLONE BY THEN.  THE OFFICIAL FORECAST IS
VERY CLOSE TO THE GFS AND THE DYNAMICAL MODEL CONSENSUS.
 
WATER VAPOR IMAGERY SUGGESTS THAT WESTERLY SHEAR IS BEGINNING TO
INCREASE OVER THE CENTER OF CIRCULATION.  GLOBAL MODELS CONTINUE TO
INDICATE THAT THE UPPER LOW TO THE WEST OF THE CYCLONE WILL
WEAKEN...ALLOWING THE SHEAR TO INCREASE.  THIS...COUPLED WITH THE
INTERACTION OF THE CENTER WITH HISPANIOLA...SHOULD RESULT IN A
DECAY OF THE SYSTEM.  A STRONG PRESSURE GRADIENT IS LIKELY TO
PERSIST TO THE NORTH OF THE DECAYING CYCLONE...HOWEVER...AND WINDS
THERE WILL BE SLOW TO DIMINISH.

THE PRIMARY THREAT FROM OLGA IS HEAVY RAINFALL...WHICH IS
ALREADY PRODUCING LIFE-THREATENING MUD SLIDES IN PUERTO RICO.
THESE RAINS WILL BE SPREADING ACROSS HISPANIOLA TONIGHT...WHERE
FLASH FLOODS AND MUD SLIDES ARE ALSO LIKELY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/2100Z 18.5N  68.8W    40 KT...INLAND
 12HR VT     12/0600Z 18.5N  71.4W    35 KT...INLAND
 24HR VT     12/1800Z 18.6N  74.5W    30 KT...OVER WATER
 36HR VT     13/0600Z 18.9N  77.8W    25 KT...REMNANT LOW
 48HR VT     13/1800Z 19.2N  80.5W    25 KT...REMNANT LOW
 72HR VT     14/1800Z 19.5N  83.0W    25 KT...REMNANT LOW
 96HR VT     15/1800Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 

WTNT42 KNHC 120233
TCDAT2
TROPICAL STORM OLGA DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
1000 PM EST TUE DEC 11 2007
 
DURING THE PAST SEVERAL HOURS THE SATELLITE PRESENTATION BECAME MORE
TYPICAL OF A TROPICAL CYCLONE SINCE DEEP CONVECTION FORMED NEAR THE
CENTER. DATA FROM AN AIR FORCE HURRICANE HUNTER PLANE INDICATED
THAT THE MAXIMUM WINDS WERE CLOSER TO THE CENTER. PEAK WINDS
MEASURED BY THE PLANE REACHED 55 KNOTS AT FLIGHT LEVEL AND 54
KNOTS BY SFMR. THE PROXIMITY OF THE WINDS TO THE CENTER AND THE
PRESENCE OF DEEP CONVECTION SUGGESTED THAT OLGA MADE THE TRANSITION
TO A TROPICAL STORM. RECONNAISSANCE AIRCRAFT COULD NOT MEASURE DATA
FROM OLGA'S CENTER BECAUSE THE CYCLONE HAD ALREADY MOVED INLAND
PRIOR TO A POSSIBLE PENETRATION.

INITIAL INTENSITY WAS ADJUSTED UPWARD TO 50 KNOTS BUT MOST LIKELY...
WEAKENING SHOULD BEGIN VERY SOON IF IT HAS NOT STARTED ALREADY DUE
TO OLGA'S INTERACTION WITH THE HIGH TERRAIN OF HISPANIOLA. EVEN
LARGE AND POWERFUL HURRICANES RARELY SURVIVE IT.
 
OLGA IS MOVING TOWARD THE WEST OR 275 DEGREES AT 13 KNOTS AROUND A
MID-LEVEL RIDGE. THIS STEERING PATTERN IS FORECAST TO PERSIST AS
INDICATED BY GLOBAL MODELS...AND OLGA OR ITS REMNANTS SHOULD
CONTINUE WESTWARD ACROSS THE CARIBBEAN SEA UNTIL DISSIPATION. IT
WOULD BE VERY DIFFICULT FOR OLGA TO RECOVER FROM THE EFFECTS OF
LAND AND EVEN MORE DIFFICULT TO OVERCOME THE EXPECTED STRONG SHEAR
ALONG ITS PATH. HOWEVER...IT IS INTERESTING TO NOTE THAT BOTH THE
GFDL AND HWRF KEEP OLGA AS A TROPICAL STORM THROUGH FIVE DAYS. 
 
THE PRIMARY THREAT FROM OLGA CONTINUES TO BE HEAVY RAINFALL AND
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN PUERTO RICO AND
HISPANIOLA. THESE RAINS SHOULD BEGIN TO SPREAD OVER EASTERN CUBA
WHICH IS ALREADY WET FROM NOEL.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0300Z 19.0N  70.6W    50 KT
 12HR VT     12/1200Z 19.0N  73.0W    35 KT
 24HR VT     13/0000Z 19.5N  76.0W    30 KT
 36HR VT     13/1200Z 19.5N  78.5W    25 KT...REMNANT LOW
 48HR VT     14/0000Z 19.5N  80.0W    25 KT...REMNANT LOW
 72HR VT     15/0000Z 19.5N  83.0W    25 KT...REMNANT LOW
 96HR VT     16/0000Z...DISSIPATED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 120845
TCDAT2
TROPICAL STORM OLGA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
400 AM EST WED DEC 12 2007
 
OLGA HAS LOST SOME ORGANIZATION DURING ITS CROSSING OF HISPANIOLA. 
THERE IS NO SIGNIFICANT CONVECTION NEAR THE CENTER AT THIS TIME...
AND THE CONVECTIVE BANDS OVER THE ATLANTIC TO THE NORTH OF
HISPANIOLA ARE RELATIVELY WEAK.  THERE ARE NO RECENT OBSERVATIONS
FROM NEAR THE CENTER OR FROM THE MAIN AREA OF CONVECTION....SO THE
INITIAL INTENSITY REMAINS 45 KT ON THIS ADVISORY.  THIS MAY BE
GENEROUS. 

THE INITIAL MOTION IS 275/16.  OLGA IS CURRENTLY ON THE SOUTH SIDE
OF A LOW/MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC...FLORIDA...AND
THE EASTERN GULF OF MEXICO.  THE LARGE-SCALE MODELS FORECAST THE
WESTERN END OF THE RIDGE TO GRADUALLY WEAKEN DURING THE NEXT 2-3
DAYS IN ADVANCE OF A DEEP-LAYER TROUGH AND ASSOCIATED COLD FRONT
MOVING THROUGH THE EASTERN UNITED STATES ON DAYS 4-5.  THIS PATTERN
EVOLUTION HAS CAUSED THE TRACK GUIDANCE TO SPLIT INTO TWO CAMPS
AFTER OLGA MOVES WESTWARD FOR 24-48 HR.  THE GLOBAL MODELS FORECAST
OLGA...OR ITS REMNANTS...TO TURN NORTHWARD AND RECURVE INTO THE
COLD FRONT MOVING ACROSS THE GULF OF MEXICO.  ON THE OTHER HAND...
THE GFDL AND HWRF FORECAST OLGA TO TURN SOUTHWEST TOWARDS THE GULF
OF HONDURAS.  THIS FORECAST MAY BE DUE TO THOSE MODELS KEEPING MORE
RIDGING WEST OF OLGA OVER THE YUCATAN PENINSULA...AND FORECASTING A
STRONG CYCLONE IN AN ENVIRONMENT OF UPPER-LEVEL NORTHWESTERLY FLOW. 
THE NEW FORECAST TRACK IS ADJUSTED NORTH OF THE PREVIOUS TRACK...
BUT WILL NOT YET CALL FOR RECURVATURE IN DEFERENCE TO THE GFDL...
HWRF...AND THE PREVIOUS FORECAST.  THE NEW TRACK IS A LITTLE TO THE
SOUTH OF THE VARIOUS CONSENSUS MODELS.

THE DYNAMICAL MODELS AGREE THAT THE UPPER-LEVEL LOW/TROUGH THAT HAS
SO FAR PROTECTED OLGA FROM SHEAR WILL WEAKEN DURING THE NEXT 24 HR
AS A RIDGE BUILDS OVER THE WESTERN CARIBBEAN.  THIS SHOULD CAUSE
STRONG NORTHWESTERLY VERTICAL WIND SHEAR TO DEVELOP OVER THE
SYSTEM.  THE INTENSITY FORECAST IS THUS UNCHANGED FROM THE PREVIOUS
ADVISORY...CALLING FOR OLGA TO WEAKEN TO A DEPRESSION IN 24 HR AND
TO A REMNANT LOW IN 36 HR.  IT SHOULD BE NOTED THAT THE GFDL AND
HWRF FORECAST OLGA TO MOVE INTO AN AREA OF LIGHTER WIND SHEAR IN
THE GULF OF HONDURAS...AND IN CONSEQUENCE BOTH MODELS FORECAST IT
TO BECOME A HURRICANE.  IT SHOULD ALSO BE NOTED THAT THE SHEAR IS
FORECAST TO BE VERY STRONG OVER THE GULF OF MEXICO...SO THE CHANCES
OF OLGA BEING A SIGNIFICANT TROPICAL CYCLONE IN THAT AREA APPEAR
RATHER LOW AT THE MOMENT.
 
THE PRIMARY THREAT FROM OLGA CONTINUES TO BE HEAVY RAINFALL AND
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN PUERTO RICO AND 
HISPANIOLA.  THESE RAINS SHOULD BEGIN TO SPREAD OVER EASTERN CUBA
TODAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0900Z 19.2N  72.5W    45 KT...INLAND
 12HR VT     12/1800Z 19.4N  74.9W    35 KT...OVER WATER
 24HR VT     13/0600Z 19.6N  77.7W    30 KT
 36HR VT     13/1800Z 19.8N  79.6W    25 KT...REMNANT LOW
 48HR VT     14/0600Z 20.0N  81.5W    25 KT...REMNANT LOW
 72HR VT     15/0600Z 20.5N  84.0W    25 KT...REMNANT LOW
 96HR VT     16/0600Z...DISSIPATED
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 121431
TCDAT2
TROPICAL STORM OLGA DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
1000 AM EST WED DEC 12 2007
 
OLGA LACKS THE CONVECTION REQUIRED OF A TROPICAL CYCLONE...AND BASED
ON VISIBLE SATELLITE IMAGERY PROBABLY ALSO LACKS A CLOSED SURFACE
CIRCULATION.  HOWEVER...WE WILL HANG ON TO OLGA FOR A FEW MORE
HOURS JUST IN CASE DEEP CONVECTION RETURNS OR WEST WINDS BECOME
EVIDENT.  A QUIKSCAT PASS AT 10Z...AS WELL AS SURFACE OBSERVATIONS
SUGGEST THAT THERE REMAINS A BAND OF TROPICAL STORM FORCE WINDS
JUST EAST OF THE TURKS AND CAICOS ISLANDS.  THE INITIAL INTENSITY
IS SET AT 35 KT BASED ON THESE DATA.  

THE VORTICITY CENTER HAS ACCELERATED...AND THE INITIAL MOTION IS
ESTIMATED TO BE 270/20.  OLGA REMAINS TO THE SOUTH OF A LOW- TO
MID-LEVEL RIDGE CENTERED JUST EAST OF FLORIDA...AND THIS RIDGE
SHOULD CONTINUE TO STEER OLGA...OR ITS REMNANTS...WESTWARD FOR THE
NEXT DAY OR TWO.  WITH DRY AIR AND STRONG SHEAR FORECAST OVER THE
NORTHWESTERN CARIBBEAN...SIGNIFICANT REGENERATION THERE IS NOT
EXPECTED.
 
THE PRIMARY THREAT FROM OLGA CONTINUES TO BE HEAVY RAINFALL AND
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN HISPANIOLA.  SOME OF
THESE RAINS SHOULD SPREAD OVER EASTERN CUBA TODAY.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/1500Z 19.1N  75.2W    35 KT
 12HR VT     13/0000Z 19.2N  77.6W    30 KT...REMNANT LOW
 24HR VT     13/1200Z 19.5N  80.5W    25 KT...REMNANT LOW
 36HR VT     14/0000Z 20.0N  82.7W    25 KT...REMNANT LOW
 48HR VT     14/1200Z 20.5N  84.5W    25 KT...REMNANT LOW
 72HR VT     15/1200Z 21.5N  86.5W    25 KT...REMNANT LOW
 96HR VT     16/1200Z...DISSIPATED
 
$$
FORECASTER FRANKLIN/MAINELLI
 

WTNT42 KNHC 122027
TCDAT2
TROPICAL DEPRESSION OLGA DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
400 PM EST WED DEC 12 2007
 
AN ASCAT PASS FROM 14Z DID NOT SHOW ANY TROPICAL STORM FORCE
WINDS...AND THE INTENSITY ESTIMATE IS LOWERED TO 30 KT.  OLGA HAS
BEEN DEVOID OF DEEP CONVECTION SINCE ABOUT 06Z...AND HAS BEEN
UNCLASSIFIABLE BY THE DVORAK TECHNIQUE SINCE THAT TIME.  HOWEVER...
THERE HAS BEEN A SLIGHT INCREASE IN CONVECTION OVER THE LAST COUPLE
OF HOURS...AND SO WE'LL HANG ON TO IT...AGAIN...JUST A LITTLE BIT
LONGER.  THE ENVIRONMENT AHEAD OF OLGA IS VERY DRY...AND THE
LONG-ANTICIPATED NORTHWESTERLY SHEAR IS BECOMING APPARENT OVER THE
CENTER.  THEREFORE...SIGNIFICANT REGENERATION IS NOT EXPECTED.
 
THE INITIAL MOTION IS 270/20. OLGA REMAINS TO THE SOUTH OF A LOW- TO
MID-LEVEL RIDGE CENTERED JUST EAST OF FLORIDA...AND THIS RIDGE
SHOULD CONTINUE TO STEER OLGA...OR ITS REMNANTS...WESTWARD FOR THE
NEXT DAY OR TWO. AFTER THAT...THE RIDGE IS FORECAST TO WEAKEN...AND
IF OLGA HAS ANY VERTICAL DEPTH AT THAT TIME IT SHOULD BEGIN TO TURN
NORTHWESTWARD...BEFORE BECOMING ABSORBED WITHIN AN APPROACHING
FRONTAL ZONE LATE IN THE PERIOD.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/2100Z 18.9N  76.9W    30 KT
 12HR VT     13/0600Z 19.1N  79.8W    25 KT...REMNANT LOW
 24HR VT     13/1800Z 19.4N  82.3W    20 KT...REMNANT LOW
 36HR VT     14/0600Z 19.9N  84.0W    20 KT...REMNANT LOW
 48HR VT     14/1800Z 20.4N  85.5W    20 KT...REMNANT LOW
 72HR VT     15/1800Z 22.0N  87.0W    20 KT...REMNANT LOW
 96HR VT     16/1800Z...DISSIPATED
 
$$
FORECASTER FRANKLIN/MAINELLI
 

WTNT42 KNHC 130233
TCDAT2
TROPICAL DEPRESSION OLGA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172007
1000 PM EST WED DEC 12 2007
 
ONCE AGAIN...I HAVE THE OPPORTUNITY TO TERMINATE ANOTHER TROPICAL
CYCLONE THIS SEASON. SATELLITE IMAGES AND RADAR FROM PILON CUBA
SHOW THAT THE CENTER OF THE DEPRESSION IS BECOMING LESS DEFINED.
THE LOW-LEVEL CIRCULATION IS STILL ESTABLISHED...BUT THERE HAS NOT
BEEN ANY SIGNIFICANT PERSISTENT CONVECTION FOR ABOUT 12 HOURS OR
SO. THE CYCLONE IS INITIALIZED AS A 25-KNOT TROPICAL DEPRESSION BUT
FORECAST TO BECOME A REMNANT LOW VERY SOON...PERHAPS AS WE SPEAK.
THERE IS ALWAYS A CHANCE THAT SOME CONVECTION REDEVELOPS
INTERMITTENTLY DURING THE NEXT DAY OR TWO...AS THE REMNANT LOW
MOVES WESTWARD ABOUT 10 TO 15 KNOTS ACROSS THE WARM WATERS OF THE
NORTHWESTERN CARIBBEAN SEA.  HOWEVER...THE SHEAR IS EXPECTED TO BE
TOO STRONG TO ALLOW REINTENSIFICATION...FAMOUS LAST WORDS.  THE
LOW WILL LIKELY BECOME ABSORBED BY AN APPROACHING COLD FRONT IN 3
DAYS OR SO OVER THE EXTREME NORTHWESTERN CARIBBEAN SEA. 

THIS WILL BE THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON OLGA UNLESS REGENERATION OCCURS. ADDITIONAL INFORMATION
ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE
NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO
HEADER FZNT01 KWBC.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/0300Z 18.9N  77.6W    25 KT
 12HR VT     13/1200Z 19.0N  80.0W    25 KT...REMNANT LOW
 24HR VT     14/0000Z 19.0N  82.0W    20 KT...REMNANT LOW
 36HR VT     14/1200Z 19.5N  83.5W    20 KT...REMNANT LOW
 48HR VT     15/0000Z 20.0N  85.5W    20 KT...REMNANT LOW
 72HR VT     16/0000Z 22.0N  86.5W    20 KT...REMNANT LOW
 96HR VT     17/0000Z...DISSIPATED
 
$$
FORECASTER AVILA
 

