000 AXNT20 KNHC 191744 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT MAY 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 1015 UTC. ...SPECIAL FEATURE... A 1009 MB LOW PRESSURE SYSTEM IS NEARLY STATIONARY OFF THE COAST OF SOUTH CAROLINA NEAR 32N77W...OR ABOUT 120 MILES SOUTHEAST OF MYRTLE BEACH. SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS EXTEND UP TO 100 NM OVER THE N AND NW QUADRANTS... AFFECTING MOSTLY THE COASTAL WATERS OF THE CAROLINAS FROM 31N-34N. DRY AIR INTRUSION IS OBSERVED OVER THE ERN AND SRN QUADRANTS NEARLY EXPOSING THE LOW LEVEL CENTER ON VISIBLE IMAGERY. THIS DRY AIR PUNCH IS RELATED TO AN ELONGATED UPPER TROUGH/WAVE EXTENDING ACROSS THE NRN GULF AND FLORIDA PENINSULA ...TO THE ERN CONUS SEABOARD ON WATER VAPOR IMAGERY. WHILE THIS SYSTEM CURRENTLY EXHIBITS BAROCLINIC CHARACTERISTICS... ADDITIONAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE...AND IT COULD BECOME A TROPICAL DEPRESSION OR TROPICAL STORM AS IT MOVES SLOWLY SOUTHWARD OR WESTWARD OVER THE NEXT DAY OR SO. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. FOR ADDITIONAL INFORMATION ON THIS SYSTEM... PLEASE SEE PRODUCTS FROM YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N23W TO 5N28W MOVING W NEAR 5-10 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE AS EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...NO DEEP CONVECTION IS OBSERVED EXCEPT A FEW WEAK ISOLATED SHOWERS IN THE VICINITY OF THE WAVE AXIS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO 200 NM OFF THE COAST OF MAURITANIA JUST N OF SENEGAL. THE ITCZ AXIS BEGINS W OF THE TROPICAL WAVE NEAR 6N31W TO 3N43W. CLUSTERS OF SCATTERED WEAK TO ISOLATED MODERATE CONVECTION ARE FROM 5N-8N E OF 30W AND FROM 7N-15N E OF 22W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL ZONAL FLOW COVERS THE REGION THIS AFTERNOON. WATER VAPOR IMAGERY DEPICTS A BROAD ELONGATED UPPER TROUGH/WAVE EMBEDDED IN THE FLOW N OF 22N. THIS FEATURE CARRIES VERY DRY AIR AND STRONG SUBSIDENCE ALOFT INTO THE BASIN. THEREFORE...THE WEATHER ACROSS THE AREA IS UNDER FAIR CONDITIONS EXCEPT FOR THE SE CORNER OF THE GULF INCLUDING THE YUCATAN CHANNEL AND THE STRAITS OF FLORIDA S OF 25N E OF 87W. THE ACTIVITY ON THIS REGION IS RELATED TO A SURFACE TROUGH EXTENDING ACROSS THE FAR NW CARIBBEAN BASIN. DOPPLER RADAR IMAGERY FROM CUBA AND SATELLITE IMAGERY INDICATE SCATTERED MODERATE TO ISOLATED HEAVY SHOWERS AND THUNDERSTORMS IN THIS AREA...EXPECTED TO LINGER OVER THE NEXT 24 HOURS. OTHERWISE...FAIR WEATHER CONDITIONS WILL PERSIST ACROSS THE REMAINDER OF THE GULF THROUGH THE MIDDLE OF NEXT WEEK. CARIBBEAN SEA... ANTICYCLONIC FLOW ALOFT COVERS THE ENTIRE CARIBBEAN BASIN ANCHORED OVER CENTRAL AMERICA. THIS FLOW IS KEEPING MOST OF THE DISCUSSION AREA CLEAR OF ACTIVE WEATHER EXCEPT THE NW...SW...AND NE BASINS. A 1008 MB LOW IS OFF THE COAST OF BELIZE NEAR 16N88W WITH A SURFACE TROUGH EXTENDING NNE TO WRN CUBA NEAR 23N83W. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE MOSTLY E OF THE TROUGH/LOW N OF 15N W OF 80W. SIMILAR CONVECTION IS OBSERVED OVER THE MONA PASSAGE AND WITHIN 50-100 NM OFF THE SRN COAST OF DOMINICAN REPUBLIC...PUERTO RICO AND THE US/UK VIRGIN ISLANDS...ASSOCIATED TO A BROAD AREA OF CYCLONIC TURNING AROUND A TROUGH AXIS ANALYZED OVER THE WRN ATLC WATERS. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THE IMMEDIATE COAST OF PANAMA AND COSTA RICA RELATED TO A SURFACE TROUGH ANALYZED INLAND ACROSS PANAMA TO NRN COLOMBIA. OTHERWISE...ESE MODERATE TO FRESH TRADE WINDS ARE ACROSS THE BASIN. THE TRADE WINDS WILL PERSIST THROUGH WEDNESDAY. THE SURFACE LOW IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS...ALLOWING FOR THE POSSIBILITY OF COASTAL FLOODING ACROSS HONDURAS...GUATEMALA... BELIZE AND THE ERN YUCATAN PENINSULA. ATLANTIC OCEAN... A LOW PRESSURE SYSTEM IS OFF THE COAST OF SOUTH CAROLINA WITH SOME POTENTIAL OF DEVELOPMENT. SEE SPECIAL FEATURE SECTION ABOVE FOR MORE DETAILS. A SURFACE TROUGH IS ANALYZED OVER THE WRN ATLC EXTENDING FROM NEAR 27N71W ACROSS THE SE BAHAMAS TO ERN CUBA NEAR 20N76W. THE BROAD CYCLONIC SURFACE WIND FIELD AROUND THE TROUGH AXIS...COMBINED WITH STRONG UPPER LEVEL DIFFLUENCE ALOFT IS GENERATING A BROAD AREA OF SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS WITHIN 150-230 NM ON EITHER SIDE OF AN IMAGINARY LINE EXTENDING FROM 30N66W ALONG 25N70W TO THE CENTRAL BAHAMAS NEAR 24N76W TO CUBA AROUND 22N79W. COMPUTER MODELS ARE IN GOOD AGREEMENT WITH THE CONVECTION LASTING THROUGH THE WEEKEND AND EARLY NEXT WEEK. OTHERWISE...A VERY BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1035 MB HIGH NEAR 37N38W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA