000
AXNT20 KNHC 292344
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE DEC 29 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER 
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...THE ITCZ...

FROM THE COAST OF SIERRA LEONE NEAR 9N13W TO 4N24W 2N40W...
CROSSING THE EQUATOR ALONG 45W/46W...INTO NORTHEASTERN BRAZIL 
NEAR 1S48W. STRONG SHOWERS FROM 2N TO 3N BETWEEN 43W AND 44W.
ISOLATED MODERATE SHOWERS ARE ELSEWHERE TO THE SOUTH OF 4N
BETWEEN 27W AND EXTREME NORTHEASTERN COASTAL BRAZIL.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH EXTENDS FROM THE EASTERN PACIFIC OCEAN 
NEAR 27N118W...TO NORTHERN MEXICO NEAR 30N110W...ACROSS THE
FAR WEST TEXAS AND MORE NORTHEASTWARD. UPPER LEVEL SOUTHWESTERLY
WIND FLOW IS EVERYWHERE TO THE EAST OF THIS TROUGH ACROSS THE
OPEN WATERS OF THE GULF OF MEXICO. HIGH LEVEL MOISTURE IS WITHIN
AT LEAST 120 NM TO 180 NM ON EITHER SIDE OF THE LINE FROM
12N110W IN THE EASTERN PACIFIC OCEAN TO 21N100W AND 25N95W...
BEYOND SOUTHEASTERN LOUISIANA. UPPER LEVEL ANTICYCLONIC FLOW
AND DRY AIR/SUBSIDENCE COVER THE REST OF THE AREA TO THE EAST
OF THE HIGH LEVEL MOISTURE.

THE CARIBBEAN SEA...
BROAD SURFACE TO LOW LEVEL FLOW CYCLONIC FLOW SPANS THE ENTIRE 
AREA. AN INDIVIDUAL CYCLONIC CENTER/TROUGH APPEARS TO BE IN 
WESTERN GUATEMALA. ISOLATED MODERATE SHOWERS...SOME DISSIPATING 
WITH TIME...ARE FROM 16N TO 18N BETWEEN 85W AND THE COAST OF 
BELIZE. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC FLOW 
COVERS THE AREA. SOME OF THE ANTICYCLONIC FLOW CUTS RIGHT ACROSS 
CENTRAL AMERICA...HELPING TO SHEAR ANY OF THE CLOUD TOPS NEAR 
BELIZE AND THE WATERS TO THE NORTH OF HONDURAS. PRECIPITATION
IS POSSIBLE ELSEWHERE TO THE SOUTH OF 21N TO THE WEST OF
82W...AND FROM 13N TO 17N MOVING FROM 70W TOWARD THE NORTHERN
COAST OF NICARAGUA.

THE ATLANTIC OCEAN...
A DISSIPATING WESTERN ATLANTIC COLD FRONT IS BEING FOLLOWED
BY A SECOND COLD FRONT. THE SECOND FRONT BROUGHT WAS PUSHED 
SOUTHEASTWARD BY A RE-INFORCING WATER VAPOR LEVEL TROUGH THAT 
MOVED ACROSS THE SOUTHEASTERN U.S.A. ABOUT 24 HOURS AGO. THE 
TROUGH AND FRONT CLEARED FLORIDA...AND NOW ARE HEADING INTO THE
CENTRAL ATLANTIC OCEAN. THE DISSIPATING FRONT IS ALONG 30N57W
25N63W TO THE DOMINICAN REPUBLIC COAST NEAR 19N64W. THE SECOND 
FRONT...THAT BROUGHT SUNRISE TEMPERATURES INTO THE 40S FAHRENHEIT
IN SOUTH FLORIDA...NOW PASSES THROUGH 32N58W 27N63W 23N70W...
ACROSS THE SOUTHERN BAHAMAS INTO CUBA NEAR 21N77W. ISOLATED 
MODERATE SHOWERS ARE WITHIN 90 NM ON EITHER SIDE OF 21N62W
26N58W BEYOND 32N54W. AN EASTERN ATLANTIC OCEAN TROUGH ON WATER 
VAPOR IMAGERY PASSES THROUGH 32N23W TO 25N30W TO 16N41W TO 
9N52W. THIS TROUGH SUPPORTS WHAT REMAINS OF THE COLD FRONT
THAT HAS BEEN IN THE ATLANTIC OCEAN FOR AT LEAST THE LAST
THREE TO FOUR DAYS...PASSING THROUGH 32N11W ACROSS THE CANARY 
ISLANDS TO 26N19W.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE.

$$
MT