000 AXNT20 KNHC 211749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF LIBERIA NEAR 6N10W TO 5N13W. THE ITCZ CONTINUES FROM 5N13W ALONG 1N24W CROSSING THE EQUATOR AT 33W TO THE COAST OF BRAZIL AT 2S47W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-6N BETWEEN 10W-18W...FROM EQ-4N BETWEEN 21W-31W...AND FROM EQ-3N BETWEEN 37W-48W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A COLD FRONT DRAPES OVER THE WRN GULF EXTENDING FROM SE LOUISIANA NEAR 29N91W TO THE MEXICO COAST ALONG 23N93W 21N97W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 30 NM AHEAD...AND 100 NM BEHIND THE FRONT WITH ISOLATED SHOWERS CONTINUING TO THE TEXAS COAST. THE FRONT IS SUPPORTED BY A CUT-OFF UPPER LEVEL LOW CENTERED OVER NRN TEXAS AT 34N100W. STRONG WINDS UP TO 30 KTS ARE BOTH IMMEDIATELY AHEAD AND BEHIND THE FRONT. THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF DRY AIR ALOFT AND SURFACE RIDGING EXTENDING FROM THE W ATLC WHICH IS PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE ERN GULF. SE WINDS UP TO 20 KTS ARE OBSERVED AS WELL AS A FEW ISOLATED SHOWERS ACROSS THE NE FLORIDA COAST. THE FRONT IS EXPECTED TO SLOWLY DRIFT E THROUGH TOMORROW BEFORE STALLING AND DISSIPATING INTO A SURFACE TROUGH WHICH WILL LIFT OUT OF THE AREA TOWARDS THE NW. SURFACE RIDGING IS EXPECTED TO BUILD BACK IN ACROSS THE BASIN OVER THE WEEKEND. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER TODAY UNDER THE INFLUENCE OF DRY AIR ALOFT IN MOSTLY SWLY FLOW. SOME ISOLATED SHOWERS ARE NOTED OVER THE FAR SE CORNER N OF VENEZUELA AS WELL AS NEAR JAMAICA. THE REMAINDER OF THE BASIN HAS MOSTLY CLEAR SKIES BESIDES SOME UPPER LEVEL CLOUDS OVER THE ERN CARIBBEAN DUE TO MOISTURE ALOFT STREAMING OVER THE TROPICAL ATLC. TRADEWIND FLOW OF 15-20 KTS IS ACROSS THE MAJORITY OF THE BASIN WITH SOME STRONGER WINDS NEAR THE COAST OF COLOMBIA. THESE STRONGER WINDS ARE HELPING PRODUCE AN AREA OF LOW-LEVEL CLOUDS N OF PANAMA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... SURFACE RIDGING COVERS THE W ATLC ANCHORED BY A 1030 MB HIGH NEAR 35N66W PROVIDING MOSTLY FAIR WEATHER. A FEW ISOLATED SHOWERS ARE NOTED ALONG THE NE FLORIDA COAST. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE OVER THE ERN CONUS. AN ELONGATED UPPER TROUGH COVERS THE CENTRAL ATLC INTO THE W ATLC WITH AXIS ALONG 40W TO 32N THEN MOVING TOWARDS THE W ALONG 32N TO 66W CONTINUING TOWARDS THE NW TO PENNSYLVANIA. THE UPPER TROUGH SUPPORTS A COLD FRONT THAT SKIMS THE AREA ALONG 32N34W TO 30N52W. ISOLATED SHOWERS ARE ALONG THE AXIS. A PAIR OF SURFACE TROUGHS ARE S OF THE FRONT. THE FIRST IS ALONG 25N45W TO 20N53W WITH ISOLATED SHOWERS NEAR THE ERN EXTENT FROM 24N-27N BETWEEN 37W-46W. THE SECOND TROUGH IS MORE VERTICALLY ALIGNED ALONG 32N30W TO 25N31W WITH SCATTERED SHOWERS MAINLY E OF THE AXIS WITHIN 45 NM AS WELL AS N OF 30N BETWEEN 23W-29W. THE FAR ERN ATLC IS COVERED BY AN UPPER LEVEL RIDGE ALONG 18W. BROAD UPPER RIDGING ALSO COVERS THE TROPICAL ATLC CENTERED NEAR 2N30W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON