000 AXNT20 KNHC 021042 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON MAY 02 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...ITCZ... ITCZ AXIS EXTENDS FROM THE NORTHERN LIBERIAN COAST NEAR 7N12W S WESTWARD ALONG 3N20W 1N30W EQ40W INTO NE BRAZIL NEAR 2S45W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 6N BETWEEN 10W-25W. SIMILAR CONVECTION IS FROM 1S-3N BETWEEN 25W-35W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE AXIS OF HIGH PRESSURE EXTENDS ACROSS THE GULF NOTED ON WATER VAPOR IMAGERY...INDICATED BY DRY AIR AND SUBSIDENCE ALOFT ACROSS THE AREA...WITH THE STRONGEST SUBSIDENCE OVER THE FAR EAST GULF. THIS AIRMASS ALOFT IS SUPPRESSING ANY CONVECTION OVER THE GULF THIS MORNING. AN UPPER LEVEL CYCLONIC CIRCULATION IS OVER FAR W CUBA TRIGGERING SOME ISOLATED SHOWERS OVER THE FAR SE BASIN S OF 25N E OF 85W INCLUDING THE STRAITS OF FLORIDA. MARINE OBSERVATIONS SHOW SSE WINDS RANGING FROM 10-20 KT ACROSS THE AREA...INCREASING TO UP TO 25 KT N OF 27N W OF 87W. THE SURFACE PRESSURE GRADIENT CONTINUES TO TIGHTEN IN THIS REGION AS A STRONG LATE SEASON COLD FRONT ENTERS THE NW GULF THIS EVENING... EXPECTED TO EXTEND FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE BY LATE TUE. COMPUTER MODELS SUGGEST THIS FRONTAL SYSTEM WILL PRODUCE NORTHERLY WINDS OF 25-30 KT...POSSIBLY HIGHER BY TUE. CARIBBEAN SEA... A SURFACE TROUGH IS MOVING ACROSS THE MONA PASSAGE...WITH AXIS ANALYZED FROM 21N64W TO 16N68W. A SECOND...WEAKER...PULSE IS MOVING OVER ANTIGUA AND BARBUDA ANALYZED FROM 19N61W TO 16N64W. THESE TWO SYSTEMS ARE BRINGING SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS TO THE EASTERN CARIBBEAN INCLUDING THE LESSER ANTILLES AND PUERTO RICO E OF 68W. THESE SYSTEMS ARE SUPPORTED ALOFT BY A COMBINATION OF A BROAD AREA OF DIFFLUENT FLOW ALOFT AND CLOSE PROXIMITY TO THE ENTRANCE REGION OF AN UPPER LEVEL JET NE OF PUERTO RICO. THIS AREA OF CONVECTION IS EXPECTED TO SLOWLY PROGRESS WESTWARD TODAY WITH LOCALLY HEAVY RAINFALL AND FLOODING OVER THE ISLANDS. ELSEWHERE ACROSS THE CARIBBEAN W OF 70W...FRESH TO STRONG EASTERLY TRADE WINDS CONTINUE AND ARE EXPECTED TO PERSIST OVER THE NEXT FEW DAYS. THESE TRADES ARE BANKING MOISTURE AND ISOLATED SHOWERS WITHIN 120 NM OF THE COAST OF COSTA RICA AND S NICARAGUA WITH THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING MOSTLY FAIR WEATHER CONDITIONS. AN UPPER LEVEL CYCLONIC CIRCULATION IS OVER FAR WEST CUBA TRIGGERING SOME ISOLATED SHOWERS OVER SOUTHERN COASTAL WATERS OF CUBA N OF 19N E OF 81W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH/CUT-OFF LOW MOVE ACROSS THE NW ATLC BARELY SUPPORTING A COLD FRONT EXTENDING INTO THE AREA FROM 32N57W TO 27N62W TO 25N69W. ISOLATED SHOWERS AND THUNDERSTORMS ARE OCCURRING WITHIN 30 NM EAST OF THE FRONT. THE FRONT IS FORECAST TO CONTINUE EASTWARD AND WEAKEN AS THE UPPER LEVEL TROUGH/LOW SHEARS OUT. SURFACE RIDGING DOMINATES THE REST OF THE ATLC ANCHORED BY A BROAD 1025 MB HIGH NEAR 37N40W. HOWEVER SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXTEND INTO THE ATLC S OF 21N BETWEEN 58W-67W FROM A PAIR OF SURFACE TROUGHS MENTIONED IN CARIBBEAN SEA DISCUSSION. CONVECTION IN THIS REGION IS EXPECTED TO SLOWLY MOVE WESTWARD OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FG