000 AXNT20 KNHC 092352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED MAR 09 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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. ...ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 06N10W CROSS THE EQUATOR NEAR 25W AND INTO NE BRAZIL NEAR 03S42W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 04N-07N BETWEEN 07W-12W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 04N BETWEEN 31W-38W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH MOVING ACROSS CENTRAL PORTIONS OF THE U.S...WITH A STRONG MID-LEVEL SHORTWAVE TROUGH EMBEDDED WITHIN OVER PORTIONS OF TEXAS AND OKLAHOMA THIS EVENING. THE ASSOCIATED SURFACE COLD FRONT AS OF 09/2100 UTC IS ANALYZED FROM VERMILION BAY NEAR 29N92W SW TO SOUTH OF BROWNSVILLE TEXAS NEAR 26N97W. A PRE-FRONTAL TROUGH IS LOCATED EAST OF THE FRONT AND EXTENDS FROM THE NEW ORLEANS AREA SW ALONG 25N94W TO 21N96W. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE NUMEROUS SHOWERS AND SCATTERED TSTMS WELL EAST OF THE FRONT ACROSS PORTIONS OF SOUTHERN GEORGIA...NORTHERN FLORIDA...AND THE NE GULF N OF 27N BETWEEN 83W AND 90W. AS THE COLD FRONT PROGRESSES EASTWARD DURING THE NEXT 24 HOURS... MINIMAL GALE CONDITIONS ARE EXPECTED IN THE SW GULF S OF 20N W OF 95W EARLY THURSDAY INTO FRIDAY. GLOBAL MODELS INDICATE THAT THE COLD FRONT WILL EXIT THE GULF LATE THURSDAY AS HIGH PRESSURE BUILDS ACROSS EASTERN TEXAS AND THE WESTERN GULF. CARIBBEAN SEA... A DRY AND STABLE ATMOSPHERE IS NOTED IN THE UPPER LEVELS ACROSS THE CARIBBEAN SEA THIS EVENING MAINTAINING GENERALLY FAIR WEATHER CONDITIONS ACROSS THE BASIN...WITH THE EXCEPTION OF AN AREA OF ISOLATED SHOWERS SOUTH OF JAMAICA AND THE TIBURON PENINSULA OF HAITI OCCURRING FROM 16N-18N BETWEEN 73W-77W. GENTLE TO MODERATE TRADE WINDS ARE OBSERVED THROUGHOUT THE BASIN...WITH THE STRONGEST WINDS TURNING CYCLONICALLY AROUND THE COASTAL WATERS NEAR THE COLOMBIA COAST WHERE SPEEDS ARE IN THE 20-25 KT RANGE AND UP TO 30 KT RIGHT ALONG THE IMMEDIATE COAST. A COLD FRONT MOVING ACROSS THE NORTHWESTERN GULF OF MEXICO CURRENTLY IS FORECAST TO PROGRESS THROUGH THE YUCATAN CHANNEL BY LATE THURSDAY INTO EARLY FRIDAY FOLLOWED BY N-NE WINDS OF 20-25 KT. UNTIL THEN...NO SIGNIFICANT CHANGES ARE EXPECTED ACROSS THE REGION. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE AXIS EXTENDS ALONG 74W ACROSS THE SW NORTH ATLC AND CONTINUES TO SUPPORT A SURFACE RIDGE WITH AXIS ALONG THE EASTERN U.S. SEABOARD ENTERING THE DISCUSSION AREA NEAR 32N75W TO EASTERN CUBA NEAR 22N78W. MOSTLY FAIR WEATHER CONDITIONS ACCOMPANY THIS RIDGE W OF 63W...HOWEVER...WITH THE APPROACH OF A COLD FRONT BY LATE THURSDAY...A PRE-FRONTAL SQUALL LINE OF TSTMS IS EXPECTED TO ENTER THE ATLC WATERS N OF 30N W OF 80W OVER THE NEXT FEW HOURS THIS EVENING. THIS INTENSE LINE OF TSTMS CURRENTLY EXTENDS FROM SAVANNAH GEORGIA SW TO THE BIG BEND REGION OF FLORIDA NEAR 30N84W AND INTO THE NE GULF. FARTHER EAST OVER THE CENTRAL ATLC...WATER VAPOR IMAGERY INDICATES A CUT-OFF UPPER LEVEL LOW CENTERED NEAR 37N57W THAT CONTINUES TO SUPPORT AN OCCLUDED 1008 MB SURFACE LOW CENTERED NEAR 36N55W. THE OCCLUSION EXTENDS SE TO A 1011 MB LOW NEAR 31N49W WITH A COLD FRONT ANALYZED SOUTHWARD TO 25N50W THEN SW TO 23N55W AS IT BECOMES MORE DIFFUSE AND RELATIVELY STATIONARY TO 23N62W. ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE BOUNDARY. A STATIONARY FRONT ALSO EXTENDS SE FROM THE LOW CENTER TO 22N35W. MOST OF THE ACTIVE WEATHER IS ASSOCIATED WITH THIS FRONT AS SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 300 NM TO THE NE OF THE FRONT. THE FRONT ALSO DELINEATES WEAK SURFACE WINDS TO THE SOUTH AND STRONGER...GRADIENT DRIVEN WINDS NORTH OF THE FRONT. MINIMAL GALE FORCE E TO SE WINDS ARE OCCURRING N OF 28N WITH AN EARLIER ASCAT PASS DEPICTING A LARGE AREA OF WINDS IN THE RANGE OF 20 TO 30 KT N OF 25N E OF THE FRONT TO 35W. ELSEWHERE OVER THE EASTERN ATLC...A SURFACE RIDGE EXTENDS FROM 32N34W TO NE OF THE CAPE VERDE ISLANDS NEAR 18N22W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN