000 AXNT20 KNHC 191730 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU APR 19 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 1715 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS INLAND ACROSS THE TROPICAL REGIONS OF WEST AFRICA INTO THE ATLC BASIN ACROSS THE COAST OF LIBERIA NEAR 6N10W TO 2N13W 3N23W 2N32W...WHERE THE ITCZ AXIS CONTINUES ALONG 1N37W TO THE COAST OF BRAZIL NEAR EQ47W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE WITHIN 140 NM ON EITHER SIDE OF THE MONSOON TROUGH E OF 33W. ...DISCUSSION... GULF OF MEXICO... A STRONG UPPER LEVEL SHORTWAVE MOVES ACROSS THE NE BASIN ON WATER VAPOR IMAGERY. THIS FEATURE IS SUPPORTING A WEAK NEARLY STATIONARY LOW PRESSURE SYSTEM OVER THE FLORIDA PANHANDLE NEAR PANAMA CITY AND ASSOCIATED COLD FRONT THAT EXTENDS SSW TO NEAR 26N85W...WHERE IT BECOMES STATIONARY TO THE ERN COAST OF THE YUCATAN PENINSULA AND FURTHER INLAND ALONG 21N87W. DOPPLER RADAR AND VISIBLE SATELLITE IMAGERY INDICATE SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS WITHIN 100 NM E OF THE BOUNDARY. THIS FRONT IS FORECAST TO SLOWLY MOVE INLAND TO CENTRAL FLORIDA OR LAKE OKEECHOBEE AREA TODAY...BEFORE LOOSING MOMENTUM AND REMAINING NEARLY STATIONARY LATER TONIGHT INTO FRIDAY. STRONG SUBSIDENCE AND DRY STABLE AIR ARE DOMINATING THE GULF W OF THE FRONT AS A SURFACE RIDGE CONTINUES TO BUILD OVER THE WRN GULF. A SECOND LOW PRESSURE SYSTEM WILL ENTER NW GULF OVER THE WEEKEND WITH NEAR GALE FORCE WINDS BEHIND IT. CARIBBEAN SEA... SCATTERED MODERATE TO HEAVY SHOWERS ARE AFFECTING THE NW BASIN N OF 16N W OF 80W. THIS AREA OF CONVECTION IS ASSOCIATED TO THE SRN EXTENSION OF A WEAK STATIONARY FRONT ALONG THE ERN EDGE OF THE YUCATAN PENINSULA. THIS AREA OF CONVECTION IS FORECAST TO REMAIN CONSTANT THROUGH THE WEEKEND. CONVERGING TRADE WIND FLOW ALONG WITH REMNANT LOW LEVEL MOISTURE IS GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 90 NM ON EITHER SIDE OF A LINE FROM GUADELOUPE TO 13N75W. THIS FLOW IS ALSO FEEDING LOW LEVEL MOISTURE TO A 1008 MB LOW ANALYZED INLAND OVER CENTRAL PANAMA...AND A SURFACE TROUGH THAT EXTENDS FROM THE SRN COAST OF NICARAGUA ALONG THE COAST OF COSTA RICA THROUGH THE SURFACE LOW TO ERN COLOMBIA. THUS...SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS COVER THE SW BASIN S OF 16N W OF W OF 75W. THIS AREA OF CONVECTION IS EXPECTED TO CONTINUE OVER THE NEXT 24 HOURS. A NEARLY STATIONARY SURFACE TROUGH IS E OF THE LESSER ANTILLES ANALYZED FROM 17N57W TO 10N60W GENERATING SCATTERED HEAVY SHOWERS AFFECTING THESE GROUP OF ISLANDS S OF BARBUDA. OTHERWISE...RELATIVELY DRY AIR AND SUBSIDENCE ALOFT COVERS A GREAT PORTION OF THE CARIBBEAN BASIN...ESPECIALLY OVER THE N-CENTRAL BASIN. SHORT RANGE COMPUTER MODELS SUGGEST SIGNIFICANT MOISTURE AND CONVECTION PENETRATING THE SE BASIN FROM SOUTH AMERICA DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... A STATIONARY FRONT ANALYZED ALONG THE COAST OF THE CAROLINAS AND GEORGIA IS GENERATING AN AREA OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 120 NM OFF THE COASTAL WATER OF THE FLORIDA PENINSULA N OF WEST PALM BEACH. OTHERWISE...AN AMPLIFIED LEVEL UPPER RIDGE OVER THE WRN ATLC SUPPORTS A WEAK 1019 MB HIGH NEAR 27N73W MAINTAINING FAIR WEATHER CONDITIONS W OF 57W. A DEEP OCCLUDED 1009 MB LOW IS CENTERED NEAR 30N56W. THE LOW LEVEL CENTER CONTINUES TO BE EXPOSED ON VISIBLE SATELLITE IMAGERY ...WITH SOME SCATTERED WEAK CONVECTION WITHIN 50 NM AROUND THE CENTER. THE ASSOCIATED COLD FRONT IS WELL DISPLACED TO THE EAST ENTERING THE REGION ALONG 32N47W TO 23N53W. SCATTERED WEAK TO ISOLATED MODERATE CONVECTION IS WITHIN 60-150 NM E OF THE FRONT WHERE LOW LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE IS MAXIMIZED. THIS LOW PRESSURE SYSTEM IS EXPECTED TO SHIFT ENE LATER THIS AFTERNOON INTO THE NIGHT HOURS. A SURFACE TROUGH IS OVER THE TROPICAL ATLC WATERS JUST E OF THE LESSER ANTILLES ANALYZED FROM 17N57W TO 10N60W GENERATING SCATTERED HEAVY SHOWERS S OF 15N W OF 54W TO OVER THE CARIBBEAN ISLANDS. OTHERWISE...A BROAD SURFACE RIDGE ANCHORED BY A 1030 MB HIGH SW OF THE AZORES OVERTAKES THE REMAINDER OF THE ATLC WITH FAIR WEATHER CONDITIONS E OF 42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA