Caribbean-On-Line's Caribbean Hurricane Blog



Hurricane Tomas

HURRICANE TOMAS DISCUSSION NUMBER 29

Published on November 5, 2010 8:39 AM | Comments

Tomas is a hurricane again and preparing to shoot straight through the Windward Passage between Haiti and Cuba, before heading to the Turks & Caicos and southern Bahamas:

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.



Hurricane Tomas Heads for Haiti, Cuba

Published on November 5, 2010 8:35 AM | Comments



Tomas Update, Thursday morning

Published on November 4, 2010 8:36 AM | Comments

This storm is proving difficult to forecast and the intensity models are are changing all the time - see this key passage from the NHC 5 AM report:

"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."

The one thing for sure is whether it is a tropical storm or hurricane is that there will be lots of rain and that may be more dangerous than the wind. It is still tracking between Haiti and Cuba through the Windward Passage, with Jamaica to the left, and the Turks & Caicos also in line at the moment. Tracking map here.

The full discussion:

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.



Tropical Storm Tomas Damage

Published on November 2, 2010 9:50 AM | Comments

Tomas already is a deadly storm, responsible for many deaths on St. Lucia and property damage there and elsewhere. Here is some tragic video from St. Lucia:



Tropical Storm Tomas Update

Published on November 2, 2010 9:36 AM | Comments

Tomas, downgraded now to a tropical storm, is taking its time, meandering in the Caribbean Sea, and starting to strengthen again. This storm has the models a bit confused, and it could take a variety of tracks, but the NHC does seem to think it will regain hurricane force again before it dies out.

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.



HURRICANE TOMAS DISCUSSION NUMBER 10

Published on October 31, 2010 11:24 AM | Comments

Currently a bit weaker, but the NHC forecast is still calling for strengthening in the 3 to 5 day period. Of more concern is the track seems to be turning to the N/NE on a line for Haiti:

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



Tomas Now a Hurricane, Threatens East Caribbean

Published on October 30, 2010 4:35 PM | Comments



Hurricane Tomas

Published on October 30, 2010 4:29 PM | Comments

Hurricane Tomas is the 12th named storm of the season, and unlike number 11, Shary, this system is currently in the Caribbean and forecast to strengthen as it heads on a path that currently brings it towards Jamaica in several days as a major hurricane. Keep checking the Caribbean On Line Hurricane Blog for updates and news on this storm.



TOMAS LASHING ST. LUCIA AND ST. VINCENT WITH STRONG WINDS AND HEAVY RAINS

Published on October 30, 2010 4:28 PM | Comments

HURRICANE TOMAS INTERMEDIATE ADVISORY NUMBER 5A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010
200 PM AST SAT OCT 30 2010

...TOMAS LASHING ST. LUCIA AND ST. VINCENT WITH STRONG WINDS
AND HEAVY RAINS...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...13.4N 61.0W
ABOUT 10 MI...15 KM NE OF ST. VINCENT
ABOUT 25 MI...40 KM S OF ST. LUCIA
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 12 MPH...19 KM/HR
MINIMUM CENTRAL PRESSURE...992 MB...29.29 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF TRINIDAD AND TOBAGO HAS DISCONTINUED THE TROPICAL
STORM WARNING FOR TRINIDAD.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* ST. VINCENT AND THE GRENADINES
* ST. LUCIA
* MARTINIQUE

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* BARBADOS
* DOMINICA
* TOBAGO
* GRENADA

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN 12 HOURS.
PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE COMPLETE.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN
THE NEXT 12 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE THE UNITED
STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM AST...1800 UTC...THE CENTER OF HURRICANE TOMAS WAS
LOCATED NEAR LATITUDE 13.4 NORTH...LONGITUDE 61.0 WEST. TOMAS IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 12 MPH...19 KM/HR...AND THIS
MOTION IS EXPECTED TO CONTINUE WITH A GRADUAL DECREASE IN FORWARD
SPEED TONIGHT AND SUNDAY. ON THE FORECAST TRACK...THE CENTER OF
TOMAS WILL PASS NEAR ST. LUCIA AND ST. VINCENT THIS AFTERNOON...
AND ENTER THE EASTERN CARIBBEAN SEA BY TONIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 75 MPH...120 KM/HR...WITH HIGHER
GUSTS. TOMAS IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS.

HURRICANE-FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO
175 MILES...280 KM. DURING THE PAST HOUR...A SUSTAINED WIND OF
48 MPH...78 KM/HR...WITH A GUST TO 69 MPH...110 KM/HR...WAS REPORTED
ON ST. LUCIA. A WIND GUST TO 51 MPH...82 KM/HR...WAS RECENTLY
REPORTED ON MARTINIQUE.

THE MINIMUM CENTRAL PRESSURE RECENTLY MEASURED BY AN AIR FORCE
RESERVE RECONNAISSANCE AIRCRAFT WAS 992 MB...29.29 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE OCCURRING ON ST. LUCIA...ST.
VINCENT...AND MARTINIQUE...AND WILL SPREAD ACROSS THE REMAINDER OF
THE WARNING AREA THROUGHOUT THE DAY AND INTO THIS EVENING.
HURRICANE CONDITIONS ARE EXPECTED WITHIN THE HURRICANE WARNING
AREA THIS AFTERNOON AT ANY TIME.

RAINFALL...TOMAS IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 4 TO 6 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 8
INCHES...ACROSS PORTIONS OF THE WINDWARD AND SOUTHERN LEEWARD
ISLANDS.

STORM SURGE...A DANGEROUS STORM SURGE WILL RAISE WATER LEVELS BY
AS MUCH AS 1 TO 3 FEET ABOVE NORMAL TIDE LEVELS WITHIN AREAS OF
ONSHORE FLOW. THE SURGE WILL BE ACCOMPANIED BY LARGE AND
POTENTIALLY DESTRUCTIVE WAVES.



Hurricane Tomas 3 Day Track

Published on October 30, 2010 4:18 PM | Comments



Hurricane Tomas

Published on October 30, 2010 4:14 PM | Comments

Unfortunately we have a semi-late in the season Hurricane in the Caribbean Sea and strengthening, Tomas:


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.