000 AXNT20 KNHC 211041 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED MAR 21 2012 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N11W TO 05N13W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N13W TO THE EQUATOR NEAR 24W THEN TO 02S43W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 04N-07N BETWEEN 12W-17W. SCATTERED MODERATE CONVECTION IS FROM 01N-05N BETWEEN 17W-21...FROM 02N-05N BETWEEN 23W-30W...AND S OF 03N BETWEEN 30W-43W. ...DISCUSSION... GULF OF MEXICO... A SLOW MOVING CUT-OFF UPPER LEVEL LOW IS CENTERED OVER WESTERN NORTH TEXAS NEAR 33N101W THIS MORNING AND CONTINUES TO SUPPORT A COLD FRONT ANALYZED INTO THE WESTERN GULF NEAR 30N93W THEN S-SW TO THE MEXICO COAST NEAR 21N97W. MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA INDICATE NUMEROUS SHOWERS AND SCATTERED TSTMS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT N OF 25N WHILE ISOLATED SHOWERS ARE OCCURRING ELSEWHERE WITHIN 90 NM EITHER SIDE OF THE FRONT S OF 25N. EAST OF THE FRONT...FRESH TO STRONG SE WINDS PREVAIL AS NOTED ON RECENT SHIP...BUOY...AND OIL PLATFORM OBSERVATIONS THIS MORNING. THESE WINDS WERE ALSO CONFIRMED BY EARLIER ASCAT AND WINDSAT SCATTEROMETER PASSES. WEST OF THE FRONT...STRONG NORTHERLY WINDS IN THE RANGE OF 20 TO 30 KT ARE FORECAST IN CLOSE PROXIMITY TO THE PASSAGE OF THE FRONT AND WILL CONTINUE THROUGH LATE WEDNESDAY AFTERNOON AS THE FRONT IS EXPECTED TO GRADUALLY WEAKEN THEREAFTER. BY EARLY FRIDAY...REMNANT SURFACE TROUGHING WILL BECOME ABSORBED AS A SURFACE RIDGE BUILDS WESTWARD THAT WILL PROVIDE MOSTLY FAIR CONDITIONS THROUGH SATURDAY. CARIBBEAN SEA... THE CARIBBEAN IS UNDER THE INFLUENCE OF WEST-SOUTHWESTERLY FLOW ALOFT WITH WATER VAPOR IMAGERY SHOWING MOST OF THE WESTERN CARIBBEAN W OF 70W UNDER MODERATELY DRY AIR AND SUBSIDENCE. EAST OF 70W...UPPER LEVEL MOISTURE AND CLOUDINESS STREAMS NE OVER THE LESSER ANTILLES AND SE CARIBBEAN S OF 17N. WITH MOSTLY DRY AIR ALOFT AND A RATHER BENIGN UPPER LEVEL PATTERN PERSISTING... MOSTLY FAIR CONDITIONS AND CLEAR SKIES ARE NOTED THIS MORNING ACROSS THE BASIN WITH ONLY A FEW ISOLATED LOW-TOPPED SHOWERS OCCURRING ACROSS SW HISPANIOLA AND OVER THE SW CARIBBEAN ALONG THE WESTERN PANAMA AND COSTA RICA COASTS. MODERATE TO FRESH E-NE TRADES WITH HIGHER WINDS OVER PORTIONS OF THE SOUTHWESTERN AND SOUTH-CENTRAL CARIBBEAN IN THE VICINITY OF THE COLOMBIAN COAST ARE FORECAST TO PERSIST THROUGH THE UPCOMING WEEKEND AS HIGH PRESSURE WILL REMAIN ANCHORED OVER THE SW NORTH ATLC. ATLANTIC OCEAN... NORTHWEST TO WESTERLY UPPER LEVEL FLOW IS ACROSS MUCH OF THE SW NORTH ATLC DUE TO BROAD UPPER LEVEL TROUGHING MOVING ACROSS THE CENTRAL NORTH ATLC. THIS OVERALL STABLE ENVIRONMENT IS SUPPORTIVE OF A 1030 MB SURFACE HIGH CENTERED NORTH OF BERMUDA NEAR 36N67W. E-NE WINDS PREVAIL W OF 50W ON THE SOUTHERN PERIPHERY OF THE HIGH WITH A STRONGER BAND OF 20 TO 25 KT WINDS NOTED FROM 20N-27N BETWEEN 55W AND THE BAHAMAS ON AN EARLIER 21/0148 UTC ASCAT PASS. FARTHER EAST AND IN CLOSER PROXIMITY TO THE UPPER LEVEL TROUGHING N OF THE DISCUSSION AREA BETWEEN 30W-50W...A COLD FRONT EXTENDS FROM 32N37W TO 31N45W TO 32N55W AND IS EXPECTED TO DRIFT SOUTHEASTWARD GRADUALLY THROUGH THE DAY WEDNESDAY. ISOLATED SHOWERS ARE POSSIBLE WITHIN 45 NM EITHER SIDE OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 32N31W TO 26N35W AND CONTINUES TO PROVIDE FOCUS FOR WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 240 NM EAST OF THE BOUNDARY N OF 29N. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A WEAKENING SURFACE RIDGE WITH AXIS FROM 32N22W TO 27N27W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN