000 AXNT20 KNHC 251750 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED APR 25 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 04N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N20W TO THE EQUATOR NEAR 31W THEN ALONG THE EQUATOR TO 43W. ISOLATED MODERATE CONVECTION IS FROM 02N-04N BETWEEN 14W-20W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG THE EASTERN U.S. SEABOARD EXTENDING INTO THE GULF OF MEXICO ALONG 27N82W TO A BROAD BASE OVER THE SW GULF NEAR 20N92W. WATER VAPOR IMAGERY INDICATES VERY DRY AIR ALOFT ACCOMPANIES THE TROUGHING WITH N-NW FLOW LOCATED WEST OF THE TROUGH AXIS. THIS OVERALL STABLE ENVIRONMENT FILTERS TO THE SURFACE AS A 1020 MB HIGH CENTERED OFF THE WESTERN COAST OF THE FLORIDA PENINSULA NEAR 28N84W WITH CLEAR SKIES NOTED ON VISIBLE SATELLITE IMAGERY. WITH THE RIDGE SLOWLY SHIFTING EASTWARD OVER THE PAST 24 HOURS...E-SE WINDS IN THE RANGE OF 10 TO 15 KT INFLUENCE THE SOUTHEASTERN HALF OF THE BASIN WITH 10 TO 20 KT S-SW WINDS ESTABLISHING OVER THE NORTHWESTERN THIRD OF THE BASIN. THURSDAY INTO FRIDAY THE RIDGE WILL CONTINUE TO SLIDE INTO THE SW NORTH ATLC AS SOUTHERLY RETURN FLOW SPREADS EASTWARD OVER MUCH OF THE GULF FOR THE WEEKEND. CARIBBEAN SEA... SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES ACROSS THE CARIBBEAN THIS AFTERNOON BETWEEN UPPER LEVEL TROUGHING TO THE NORTH OVER THE GULF OF MEXICO AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SE CARIBBEAN NEAR 11N64W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO BE CONCENTRATED TO THE SE OF THE TROUGH AXIS THAT SUPPORTS A STATIONARY FRONT EXTENDING FROM THE SW NORTH ATLC ACROSS NW HISPANIOLA TO 15N77W. A SURFACE TROUGH IS ALSO ANALYZED EAST OF THE FRONT FROM 18N70W TO 15N74W TO 10N76W. WITH THESE BOUNDARIES IN PLACE ACROSS THE CENTRAL CARIBBEAN...MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE COUPLED WITH FAVORABLE UPPER LEVEL DIFFLUENCE CONTINUES TO GENERATE SCATTERED TO NUMEROUS SHOWERS AND WIDELY SCATTERED TSTMS WITHIN 240 NM EITHER SIDE OF A LINE FROM 20N70W TO 12N78W. THE FRONT IS EXPECTED TO WEAKEN OVER THE NEXT 24 TO 36 HOURS AS SURFACE RIDGING BUILDS TO THE NORTH AND EASTERLY TRADES INCREASE DUE TO A STRONGER PRESSURE GRADIENT. IT IS POSSIBLE THAT LOW-LEVEL MOISTURE WILL LINGER ACROSS THE NORTH-CENTRAL CARIBBEAN FOR THE NEXT DAY OR TWO AS THE FRONT BECOMES MORE DIFFUSE AND WILL CONTINUE TO PROVIDE INCREASED PROBABILITY OF PRECIPITATION FOR HISPANIOLA AND THE ADJACENT COASTAL WATERS THROUGH THE WEEKEND. THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND FLOODING ACROSS HAITI AND PORTIONS OF THE DOMINICAN REPUBLIC ARE EXPECTED THE NEXT FEW DAYS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG THE U.S. EASTERN SEABOARD AND INTO THE GULF OF MEXICO. MOSTLY SOUTHWESTERLY UPPER LEVEL FLOW IS ACROSS THE SW NORTH ATLC REGION TO 57W WITH WATER VAPOR IMAGERY INDICATING THIS FLOW REMAINS VERY DRY ALOFT S OF 30N. WHILE MOST OF THE STRONGER UPPER LEVEL DYNAMICS REMAIN NORTH OF THE DISCUSSION AREA...THE TROUGH CONTINUES TO SUPPORT A STATIONARY FRONT ANALYZED FROM 32N62W TO 25N65W TO NORTHERN HISPANIOLA NEAR 20N70W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 210 NM EITHER SIDE OF THE FRONT S OF 30N AND WITHIN 150 NM EAST OF THE FRONT N OF 30N. HIGH PRESSURE IS EXPECTED TO BUILD IN FROM THE GULF OF MEXICO ACROSS THE SW NORTH ATLC OVER THE WEEKEND. FARTHER EAST...SUBTROPICAL RIDGING DOMINATES ANCHORED BY A 1036 MB HIGH CENTERED WELL NORTH OF THE REGION NEAR 49N43W. A SLIGHT WEAKNESS REMAINS ON THE SOUTHERN PERIPHERY OF THE RIDGE DUE TO AN UPPER LEVEL LOW CENTERED NEAR 26N39W. A SURFACE TROUGH ANALYZED FROM 30N49W TO 19N46W CONTINUES TO DRIFT WESTWARD WHILE MOST OF THE SCATTERED ELEVATED CONVECTIVE SHOWERS ARE OCCURRING FROM 22N-28N BETWEEN 35W-44W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN