000
AXNT20 KNHC 020548
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST THU DEC 02 2010

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0545 UTC.

...ITCZ...
 
THE ITCZ AXIS IS ANALYZED FROM THE COAST OF GUINEA-BISSAU NEAR 
11N15W WESTWARD ALONG 7N20W 5N30W 7N40W 8N46W TO INLAND OVER 
SOUTH AMERICA NEAR 6N57W. SCATTERED MODERATE TO STRONG 
CONVECTION IS FROM THE EQUATOR LINE TO 10N BETWEEN 28W AND 40W. 
ISOLATED MODERATE CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF 
THE AXIS BETWEEN 21W AND 27W.

...DISCUSSION...

GULF OF MEXICO...
A CONTINENTAL DRY AND COLD AIRMASS IS IN PLACE ACROSS THE 
GULF...AFTER THE PASSAGE OF THE COLD FRONT THAT IS NOW OVER THE 
WEST ATLANTIC. ANTICYCLONIC FLOW OF UP TO 15 KT IS OBSERVED 
ACROSS THE AREA...AROUND A 1027 MB HIGH CENTERED OFF THE COAST 
OF LOUISIANA NEAR 29N92W. COLD AIR OVER RELATIVELY WARM WATERS 
HAVE YIELD LOW LEVEL STRATOCUMULUS CLOUDS OVER A GREAT PART OF 
THE BASIN S OF 25N. A RATHER TIGHT SURFACE PRESSURE GRADIENT 
REMAINS OVER THE BAY OF CAMPECHE AND THE FAR SE BASIN S OF 25N E 
OF 87W WITH GUSTY NE WINDS UP TO 20 KT. STRONG SUBSIDENCE ALOFT 
IS OVER THE ENTIRE GULF NOTED ON WATER VAPOR IMAGERY. EXPECT 
WINDS TO CONTINUE TO DECREASE OVER THE NEXT 24 HOURS AS RIDGING 
BUILDS ACROSS THE BASIN.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS DRY AND SUBSIDENT AIR ALOFT ACROSS THE 
CARIBBEAN EXCEPT THE FAR NW AND SW CORNERS OF THE BASIN. THE 
MOST REMARKABLE SUBSIDENCE IS OVER THE NE BASIN. THE COLD FRONT 
THAT IS OVER THE WEST ATLC EXTENDS S ACROSS THE NW CARIBBEAN 
FROM WESTERN CUBA TO HONDURAS ALONG 22N81W 19N84W 15N87W. 
OVERCAST LOW LEVEL STRATOCUMULUS CLOUDS AND SCATTERED SHOWERS 
ARE BEHIND  FRONT. A BROAD AREA OF LOWER PRESSURE CONTINUES TO 
COVER THE FAR SW CARIBBEAN AND IS ROUGHLY CENTERED NEAR A 1009 
MB LOW OFF THE COAST OF PANAMA NEAR 10N80W. THIS SYSTEM IS ALSO 
INFLUENCED BY SURFACE CONVERGENCE IN THE VICINITY OF THE ITCZ 
THAT CROSSES FROM COSTA RICA TO NORTHERN COLOMBIA GENERATE 
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 11N W OF 75W. 
FURTHERMORE...AS THE ITCZ AXIS EXTENDS ACROSS THE NORTH PORTION 
OF SOUTH AMERICA...EXPECT CONVECTION TO FLARE UP DURING THE 
DAYTIME HOURS OVER THE COASTAL WATERS OF VENEZUELA W OF 66W. 
15-20 KT TRADE WINDS ARE E OF THE FRONT WITH THE STRONGEST WINDS 
S OF HISPANIOLA TO COLOMBIA. 
 
ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH/LONGWAVE MOVES OFF THE EASTERN CONUS 
SEABOARD. THIS UPPER LEVEL FEATURE SUPPORTS THE COLD FRONT OVER 
THE W ATLANTIC THAT ENTERS THE AREA OF DISCUSSION ALONG 32N70W 
EXTENDING SW ACROSS THE BAHAMAS NEAR 26N76W TO WESTERN CUBA NEAR 
22N81W. ISOLATED SHOWERS ARE WITHIN 60 NM NW OF FRONT. 20 KT NW 
WINDS ARE N OF FRONT WITH COLD AIR ADVECTION. UPPER LEVEL 
RIDGING IS AHEAD OF THE COLD FRONT AND SUPPORTS A WEAK 1019 MB 
HIGH NEAR 29N66W...KEEPING CONDITIONS FAIR ACROSS THE REMAINDER 
OF THE WESTERN ATLC. A BROAD ELONGATED UPPER LEVEL LOW IS OVER 
THE NORTH CENTRAL ATLANTIC SUPPORTING A SURFACE LOW PRESSURE 
SYSTEM THAT EXTENDS A COLD FRONT ALONG 32N31W 23N40W 16N48W. A 
PRE-FRONTAL TROUGH IS FROM 20N40W TO 12N48W. THIS SCENARIO IS 
PRODUCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS 
FROM 12N TO 32N BETWEEN 30W AND 40W. WEAK SURFACE RIDGE COVERS 
THE REMAINDER OF THE EASTERN ATLC THE COAST OF W AFRICA. 

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

$$

GARCIA