000 AXNT20 KNHC 071738 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON MAY 07 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 1645 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE SRN COAST OF GUINEA AT 9N13W CONTINUING ACROSS ATLC WATERS TO 6N19W. THE ITCZ CONTINUES FROM 6N19W ALONG 4N36W 2N52W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 200 NM S OF THE AXIS BETWEEN 13W-32W. ...DISCUSSION... THE GULF OF MEXICO... DRY AIR ALOFT IN MAINLY WLY FLOW IS KEEPING THE GULF OF MEXICO UNDER MOSTLY FAIR CONDITIONS TODAY. A SHORTWAVE UPPER TROUGH EXTENDS OVER NRN FLORIDA SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM A COLD FRONT IN THE W ATLC. THE TROUGH AXIS IS FROM 29N83W TO 27N92W. WIDELY ISOLATED LOW-LEVEL SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE AXIS. A WEAK PRESSURE GRADIENT IS SUPPORTING MAINLY LIGHT SE-S SURFACE FLOW...EXCEPT FOR N OF THE SURFACE TROUGH WHERE ELY FLOW IS PRESENT. EXPECT THE WEAK SURFACE TROUGH TO REMAIN OVER THE NRN GULF FOR THE NEXT 24 HOURS WITH POSSIBLE ISOLATED SHOWERS NEAR IT. THE CARIBBEAN SEA... TRANQUIL CONDITIONS SPREAD OVER MUCH OF THE WRN AND CENTRAL CARIBBEAN TODAY DUE TO DRY AIR ALOFT IN ZONAL WLY FLOW. LIGHT 5-10 KT TRADEWIND FLOW IS ALSO PRESENT ACROSS MUCH OF THIS AREA. HOWEVER...A SURFACE TROUGH IMPACTS THE ERN CARIBBEAN EXTENDING FROM 18N63W TO VENEZUELA AT 12N70W. MOST OF THE SHOWER ACTIVITY IS E OF THE AXIS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS EXTENDING FROM 13N-18N E OF 65W. MANY OF THE WINDWARD AND LEEWARDS ISLANDS ARE AFFECTED BY THESE SHOWERS AND THUNDERSTORMS. STRONG SHOWERS/THUNDERSTORMS ARE ALSO OVER MUCH OF COLOMBIA AND PORTIONS OF PANAMA DUE TO THE E PACIFIC MONSOON TROUGH WHICH EXTENDS INTO THE EXTREME SW CARIBBEAN FROM 9N79W TO 10N76W. EXPECT THE SURFACE TROUGH TO REMAIN OVER THE ERN CARIBBEAN FOR THE NEXT COUPLE OF DAYS ACCOMPANIED BY SHOWERS/THUNDERSTORMS. THE ERN CARIBBEAN ISLANDS COULD BE AT RISK OF LOCALIZED FLOODING IF STRONG SHOWERS MOVE OVER THEM. THE ATLANTIC OCEAN... A SHORTWAVE UPPER TROUGH IS CURRENTLY MOVING OFF THE COASTS OF FLORIDA...GEORGIA...AND THE CAROLINAS SUPPORTING A COLD FRONT EXTENDING FROM A WEAK 1010 MB LOW NEAR 30N72W TO THE NRN FLORIDA COAST AT 29N81W. SCATTERED SHOWERS/THUNDERSTORMS ARE PRESENT RIGHT ALONG THE FLORIDA COAST FROM 28N-30N...AS WELL AS NEAR THE LOW CENTER FROM 29N-30N BETWEEN 66W-72W. A WEAK UPPER LEVEL RIDGE IS ALONG 68W SUPPORTING A 1015 MB HIGH S OF THE LOW CENTER NEAR 24N70W. A LONGWAVE UPPER LEVEL TROUGH COVERS MUCH OF THE N CENTRAL ATLC SUPPORTING ANOTHER COLD FRONT ALONG 32N45W 28N52W 28N61W BECOMING STATIONARY TO THE AFOREMENTIONED SURFACE LOW AT 30N72W. SCATTERED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE COLD AND STATIONARY FRONTS. A SECOND FRONTAL BOUNDARY IS FARTHER E WITH A DISSIPATING STATIONARY FRONT EXTENDING FROM 31N32W TO 21N56W. MOIST SWLY FLOW ALOFT COVERS MUCH OF THIS AREA...WHICH HELPS SUPPORT OVERCAST SKIES AND SCATTERED SHOWERS ALONG A 350 NM WIDE SWATH FROM THE NE CARIBBEAN TO THE CANARY ISLANDS. AN UPPER LEVEL JET IN THE SWLY FLOW ALOFT IS HELPING SUPPORT THE SCATTERED SHOWERS. A BROAD UPPER LEVEL RIDGE COVERS MUCH OF THE TROPICAL ATLC AND ERN ATLC EXTENDING FROM NRN SOUTH AMERICA TO PORTUGAL AND SPAIN. IT IS HELPING SUPPORT AN ELONGATED SURFACE RIDGE EXTENDING FROM A 1022 MB HIGH S OF PORTUGAL AT 36N7W TO 15N47W. EXPECT THE DISSIPATING FRONT TO CONTINUE DISSIPATING EVEN THOUGH THE UPPER LEVEL JET WILL LIKELY CONTINUE TO PRODUCE SHOWERS. THE COLD FRONT FARTHER W WILL CONTINUE TO MOVE EWD INTO THE CENTRAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON