000 AXNT20 KNHC 201752 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN MAR 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... THE ITCZ AXIS EXTENDS FROM CENTRAL LIBERIA NEAR 6N10W ALONG 5N15W EQ24W DEPICTING SWLY/WLY FLOW CONVERGENCE. E OF 24W...THE ITCZ AXIS EXTENDS ALONG THE EQUATOR TO 35W CONTINUING ALONG 2N43W 1N51W DEPICTING CONVENTIONAL ITCZ FLOW OF NELY/SELY WIND CONVERGENCE. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM 2N-7N BETWEEN 11W-16W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-3N BETWEEN 16W-19W...FROM 2S-1N BETWEEN 29W-34W...AND FROM 2N-3N BETWEEN 39W-44W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING CONTINUES TO DOMINATE THE GULF OF MEXICO AROUND A 1039 MB HIGH CENTERED NEAR MONTREAL WITH AXIS EXTENDING DOWN THE ERN UNITED STATES AND ACROSS THE GULF FROM NE FLORIDA TO THE BAY OF CAMPECHE. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE MOVING ACROSS THE GULF CENTERED OVER CENTRAL MEXICO WITH AXIS EXTENDING NE ACROSS THE ENTIRE ERN CONUS. WATER VAPOR IMAGERY INDICATES DRY AIR AND SUBSIDENCE ARE ACROSS THE BASIN SUPPORTING MOSTLY FAIR CONDITIONS ACROSS THE AREA WITH CLEAR SKIES THROUGHOUT BESIDES A FEW PATCHES OF LOW LEVEL CLOUDS. WINDS ARE LIGHT AND VARIABLE ACROSS THE NE GULF BECOMING ELY ACROSS THE SE GULF UP TO 15 KTS. WINDS ARE MAINLY SE OVER THE WRN GULF APPROACHING 20 KTS NEAR THE SE TEXAS COASTLINE. A WEAK AND DISSIPATING STATIONARY BOUNDARY CLIPS THE FAR NE CORNER OF FLORIDA CAUSING NO SIGNIFICANT WEATHER. THE SURFACE RIDGE IS EXPECTED TO REMAIN STATIONARY AS A FRONTAL BOUNDARY DISSIPATES MAINTAINING FAIR CONDITIONS ACROSS THE BASIN FOR THE NEXT SEVERAL DAYS. CARIBBEAN SEA... THE CARIBBEAN IS UNDER THE INFLUENCE OF A DRY AND STABLE AIRMASS WHICH IS INHIBITING DEEP CONVECTION AND MAINTAINING MOSTLY FAIR CONDITIONS ACROSS TEH BASIN. HOWEVER...A FEW TRADEWIND SHOWERS ARE NOTED IN THE NELY FRESH TO STRONG TRADEWIND FLOW ESPECIALLY EVIDENT ACROSS PUERTO RICO IN RADAR AND SATELLITE IMAGERY. ISOLATED SHOWERS ARE ALSO ACROSS THE NRN WINDWARD ISLANDS AS WELL AS INLAND OVER PORTIONS OF HONDURAS. SOME OF THE SHOWERS ACROSS THE WINDWARD ISLANDS ARE DUE TO WIND SPEED CONVERGENCE ALONG A SHEAR LINE EXTENDING FROM THE TROPICAL ATLC ALONG 13N60W 10N64W. THE SURFACE WINDS ALSO GAIN A CYCLONIC NATURE AROUND THE COAST OF COLOMBIA WITH WINDS REACHING 25 KT CAUSING DAMMING AGAINST THE COSTA RICA AND PANAMA COASTS SUPPORTING OVERCAST SKIES AND POSSIBLE SHOWERS. ALOFT...UPPER LEVEL RIDGING DOMINATES THE MAJORITY OF THE BASIN WHILE A DRY UPPER LEVEL TROUGH EXTENDS FROM THE W ATLC ACROSS CENTRAL CUBA TO HONDURAS. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A MOSTLY DRY COLD FRONT IS PUSHING INTO THE W ATLC ALONG 32N61W 29N71W 29N78 BECOMING A DISSIPATING STATIONARY FRONT ACROSS NE FLORIDA. THE FRONT IS SUPPORTED BY A LONGWAVE UPPER TROUGH BETWEEN 45W-75W. THE FRONT EXTENDS THROUGH A STRONG SURFACE RIDGE OVER THE ERN CONUS AND W ATLC CENTERED NEAR MONTREAL. ISOLATED SHOWERS ARE ALONG THE FRONTAL BOUNDARY WITH POSSIBLE ISOLATED SHOWERS WITHIN 100 NM BEHIND THE FRONT. THE REMAINDER OF THE W ATLC IS EXPERIENCING FAIR WEATHER DUE TO DRY AIR ALOFT. A WEAKENING SHORTWAVE UPPER TROUGH IS IN THE CENTRAL ATLC ALONG 45W SUPPORTING A 1008 MB SURFACE LOW NEAR 28N49W. A WARM FRONT EXTENDS FROM THE LOW CENTER EWD TO 28N43W. A SURFACE TROUGH EXTENDS SWD TO NEAR 22N51W. A SECOND SURFACE TROUGH EXTENDS ALONG 22N49W TO 16N54W CONTINUING AS A SHEAR AXIS TO THE WINDWARD ISLANDS NEAR 13N61W. SCATTERED SHOWERS ARE WITHIN 120 NM N OF THE WARM FRONT...300 NM E OF THE TROUGH CONNECTED TO THE LOW CENTER...AND 150 NM E OF THE SECOND SURFACE TROUGH. SURFACE RIDGING COVERS THE REMAINDER OF THE FAR E ATLC AROUND A 1020 MB HIGH NEAR 26N25W MAINTAINING FAIR CONDITIONS. ALOFT...MAINLY ZONAL WLY FLOW IS S OF 25N AROUND A BROAD UPPER RIDGE CENTERED OVER THE TROPICAL ATLC NEAR 4N42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON