000 AXNT20 KNHC 112337 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAR 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF LIBERIA NEAR 5N9W TO 4N12W. THE ITCZ CONTINUES FROM 4N12W CROSSING THE EQUATOR AT 26W TO THE COAST OF BRAZIL NEAR 4S45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-6N BETWEEN 10W-18W. SIMILAR ACTIVITY IS FROM EQ-1S BETWEEN 22W-25W...AND FROM 6S-1S BETWEEN 32W-40W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING COVERS MUCH OF THE GULF OF MEXICO THIS EVENING WITH AXIS ALONG 86W. HOWEVER...AN UPPER LEVEL LOW MOVING QUICKLY ACROSS THE CENTRAL CONUS CURRENTLY ENTERING NEBRASKA IS SUPPORTING A FRONTAL BOUNDARY IN THE WRN GULF. AS OF 2100 UTC...THE FRONT HAS BECOME STATIONARY FROM ERN TEXAS AT 30N95W TO 22N96W WHERE IT TRANSITIONS INTO A SURFACE TROUGH INTO MEXICO NEAR 17N93W. A LINE OF SHOWERS IS ALONG THE FRONT AXIS WITH POSSIBLE ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE THE AXIS. THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF SURFACE RIDGING EXTENDING FROM THE NW ATLC. E-SE SURFACE WINDS OF 15-20 KTS ARE AROUND THE RIDGE. A SWATH OF MOISTURE IS EMBEDDED WITHIN THIS FLOW ACROSS MUCH OF THE FLORIDA PENINSULA WHERE ISOLATED SHOWERS ARE PRESENT THROUGHOUT. THE FRONT IS EXPECTED TO LIFT BACK TOWARDS THE NW AS THE SURFACE RIDGE BUILDS IN ACROSS THE BASIN MAINTAINING E-SE FLOW. CARIBBEAN SEA... DRY AIR ALOFT IS SINKING S ACROSS THE WRN HALF OF THE CARIBBEAN AROUND AN UPPER LEVEL TROUGH EXTENDING FROM THE WINDWARD PASSAGE TO N OF COLOMBIA. THE DRY AIR IS MAINTAINING FAIR CONDITIONS ACROSS MUCH OF THE BASIN BESIDES THE SE CORNER WHERE MOISTURE IS BEING DRAWN AROUND THE ERN SIDE OF THE UPPER TROUGH. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE S OF 16N E OF 70W INCLUDING THE SRN WINDWARD ISLANDS. TRADEWIND FLOW OF 15-20 KTS IS ACROSS MUCH OF THE AREA REACHING 30 KTS NEAR THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE OVER THE ERN GULF OF MEXICO AND ERN CONUS SUPPORTS SURFACE RIDGING ACROSS THE W ATLC ANCHORED BY A PAIR OF HIGH PRESSURE CENTERS...A 1036 MB HIGH NEAR 37N75W...AND A 1034 MB HIGH NEAR 40N65W. AN UPPER LEVEL TROUGH TO THE E ALONG 57W SUPPORTS A 1013 MB SURFACE LOW NEAR THE DISCUSSION BORDER AT 31N54W. A DISSIPATING COLD FRONT EXTENDS FROM THE LOW CENTER TO 27N66W WHERE IT BECOMES STATIONARY TO THE NRN BAHAMAS NEAR 26N77W. ISOLATED SHOWERS ARE WITHIN 50 NM EITHER SIDE OF THE AXIS. A SURFACE TROUGH ALSO EXTENDS S FROM THE LOW CENTER ALONG 26N57W...WITH POSSIBLE ISOLATED SHOWERS ALONG IT. THE MAIN SHOWER ACTIVITY IS FARTHER E UNDER THE AREA OF STRONGEST DIFFLUENCE ALOFT. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 24N BETWEEN 47W-52W. FARTHER E...AN UPPER LEVEL RIDGE ALONG 40W SUPPORTS SURFACE RIDGING ACROSS THE E ATLC AROUND A 1027 MB HIGH NEAR 34N39W. AN UPPER LEVEL TROUGH COVERS THE FAR ERN ATLC ALONG 22W SUPPORTING WEAK SURFACE TROUGHING OVER WRN AFRICA. THE LAST VISIBLE SATELLITE IMAGES ALONG WITH GOES-R ENHANCEMENTS REVEAL AN AREA OF AFRICAN DUST EXTENDING 37W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON