000 AXNT20 KNHC 012345 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAY 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2335 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE NRN COAST OF GUINEA NEAR 11N15W TO 6N16W TO 3N21W...WHERE THE ITCZ AXIS CONTINUES ALONG 1N32W TO THE COAST OF BRAZIL NEAR 2S45W. SCATTERED MODERATE TO STRONG CONVECTION MOVES OFF THE COAST OF LIBERIA AND SIERRA LEONE E OF 15W. ISOLATED WEAK CONVECTION IS WITHIN 140 NM ON EITHER SIDE OF THE ITCZ BETWEEN 22W-40W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH MOVES ACROSS THE N-CENTRAL GULF THIS EVENING ...ANALYZED FROM 29N86W TO 24N89W. SCATTERED WEAK TO MODERATE SHOWERS AND ISOLATED THUNDERSTORMS EXTEND UP TO 130 NM FROM EITHER SIDE OF THE TROUGH AXIS. MOST OF THIS ACTIVITY IS HEADING TO THE LOUISIANA AND MISSISSIPPI COAST E OF 92W INDICATED BY DOPPLER RADAR IMAGERY. LAST VISIBLE SATELLITE PICTURES OF THE DAY SHOWED A MID-LEVEL CYCLONIC CIRCULATION ALONG THE TROUGH AXIS NEAR 26N89W. HOWEVER...THE CLOUD PATTERN INDICATED THE CIRCULATION WAS OPENING AS THIS FEATURE LOOSES UPPER LEVEL SUPPORT...AND WESTERLY ZONAL FLOW ALOFT SETTLES ACROSS THE AREA ON WATER VAPOR IMAGERY. FAIR WEATHER CONDITIONS ARE ELSEWHERE ACROSS THE REMAINDER OF THE GULF. MARINE OBSERVATIONS SHOW ESE WINDS 10-20 KT ACROSS THE AREA...GUSTING TO 25 KT IN THE VICINITY OF THE SURFACE TROUGH. THIS FEATURE IS EXPECTED TO CONTINUE TO TRACK NW TO INLAND OVER THE SOUTHERN STATES AND LEAVING A TRAIL OF LINGERING ISOLATED MODERATE TO HEAVY SHOWERS OVER THE NE AND N-CENTRAL GULF BASINS LASTING THROUGH FRIDAY. CARIBBEAN SEA... MOST OF THE CARIBBEAN BASIN IS UNDER MIDDLE TO UPPER LEVEL SUBSIDENCE AND DRY AIR ON WATER VAPOR IMAGERY THIS EVENING... ESPECIALLY OVER THE NW BASIN. HOWEVER...TOTAL PRECIPITABLE WATER IMAGERY INDICATES MODERATE TO HIGH VALUES OF MOISTURE ENTERING THE ERN BASIN...WHERE A BROAD AREA OF TROUGHINESS IS OBSERVED IN THE EASTERLY FLOW PATTERN ACROSS THIS REGION. LOW LEVEL CONVERGENCE COMBINED WITH PLENTY OF LOW LEVEL MOISTURE IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS N OF 14N E OF 68W INCLUDING THE WATERS NEAR THE LESSER ANTILLES. SIMILAR ACTIVITY REMAINS OVER THE SRN COASTAL WATERS OF CUBA WITHIN 50-80 NM BETWEEN 74W-82W. THE MONSOON TROUGH EXTENDS NEAR THE COASTAL WATERS FROM COSTA RICA TO NRN COLOMBIA ALONG 10N. MOST OF THE ACTIVITY ASSOCIATED TO THIS FEATURE REMAINS INLAND. SHORT RANGE COMPUTER MODELS SUGGEST THE ACTIVITY OVER THE N-ERN CARIBBEAN WILL SLOWLY INCREASE AND EXPAND DURING THE NEXT 24-48 HRS. ATLANTIC OCEAN... A WEAK UPPER LEVEL SHORTWAVE SLOWLY MOVES ACROSS THE FAR SW NORTH ATLC GENERATING A BROAD AREA OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 27NW OF 65W...WITH THE HEAVIEST CONCENTRATION OF SHOWER ACTIVITY OVER THE SE BAHAMAS AND TURKS AND CAICOS ISLANDS. COMPUTER MODELS HAVE SOME DISAGREEMENTS REGARDING HOW LONG THIS AREA OF CONVECTION WILL REMAIN ACROSS THE AREA...ESPECIALLY OVER THE HEAVIEST ACTIVITY MENTIONED ABOVE. A COLD FRONT ENTERED THE DISCUSSION AREA THIS AFTERNOON...EXTENDING ALONG 30N50W TO 28N55W TO 30N64W. SCATTERED WEAK SHOWERS ARE OBSERVED WITHIN 30 NM ON EITHER SIDE OF THE FRONT. THE ACTIVITY IS SUPPORTED ALOFT BY A SHORTWAVE TRACKING SE INTO THE AREA ALONG 27N55W. A SURFACE TROUGH IS LOCATED SE OF THE FRONTAL BOUNDARY...ANALYZED FROM 29N48W TO 22N52W WITHOUT ANY SHOWER ACTIVITY. THE REMAINDER OF THE ATLC BASIN IS UNDER THE INFLUENCE OF SURFACE RIDGING ACROSS THE AREA E OF 44W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA