000 AXNT20 KNHC 241747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUL 24 2011 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 1730 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE CENTRAL TROPICAL ATLC ANALYZED FROM 16N35W TO 9N41W MOVING W AT 10-15 KT. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE BROAD CYCLONIC LOW-LEVEL FLOW IN THE VICINITY OF THE WAVE AXIS WHICH REMAINS EMBEDDED WITHIN THE ITCZ AXIS. THIS WAVE IS EMBEDDED IN A DEEP MOISTURE SURGE ON TOTAL PRECIPITABLE WATER IMAGERY. A TROPICAL WAVE MOVES ACROSS HISPANIOLA ANALYZED FROM 24N71W TO 16N71W MOVING W-NW AT 15 KT. VISIBLE SATELLITE IMAGERY INDICATES BROAD CYCLONIC TURNING OF THE LOW-MID LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE AXIS. TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS A LARGE AREA OF ENHANCED DEEP LAYER MOISTURE ACROSS HISPANIOLA. SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE OCCURRING FROM 17N-23N BETWEEN 69W-76W. THIS AREA INCLUDES THE NORTH-CENTRAL CARIBBEAN WATERS AND THE WATERS CLOSE TO THE EASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED AS THE SYSTEM MOVES WNW OVER THE NEXT 24 HOURS. THIS ACTIVITY COULD GENERATE FLASH FLOODING AND MUDSLIDES OVER SATURATED-HIGH TERRAIN AND RIVERS DURING THE FORECAST PERIOD. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST OF GUINEA-BISSAU NEAR 12N16W TO 8N21W TO 6N27W. THE ITCZ AXIS CONTINUES FROM THIS POINT TO 10N36W...RESUMING WEST OF A TROPICAL WAVE NEAR 1241 ALONG 9N52W TO NEAR TRINIDAD AND TOBAGO NEAR 10N61W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 80-100 NM ON EITHER SIDE OF THE MONSOON TROUGH. ISOLATED WEAK TO MODERATE CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... ANTICYCLONIC FLOW WITH MODERATE SUBSIDENCE ALOFT COVERS MUCH OF THE NORTHERN HALF OF THE GULF ON WATER VAPOR IMAGERY. THIS UPPER LEVEL ENVIRONMENT SUPPORTS A 1022 MB HIGH CENTERED IN THE NE GULF NEAR 29N87W. AN UPPER LEVEL LOW IS MOVING ACROSS THE NW CARIBBEAN SEA PROVIDING AMPLE MIDDLE TO UPPER LEVEL LIFT ACROSS THE SE GULF...PRODUCING WEAK ISOLATED SHOWERS S OF 26N E OF 90W...INCLUDING THE FLORIDA STRAITS. STRONGER CONVECTION IS FOUND OVER THE N CENTRAL GULF AFFECTING THE COASTAL WATERS OF LOUISIANA AND MISSISSIPPI WITHIN 30-50 NM BETWEEN 88W-94W. THIS AREA OF CONVECTION IS ASSOCIATED TO A MID LEVEL TROUGH EXTENDING ACROSS THE S CENTRAL CONUS. THE ACTIVITY OS EXPECTED TO LINGER OVER THE NEXT 24 HOURS. SSE TO RETURN SURFACE FLOW 5-15 KT IS OBSERVED ACROSS THE AREA THIS AFTERNOON. CARIBBEAN SEA... AN UPPER LEVEL LOW MOVES ACROSS THE NW CARIBBEAN...HOWEVER...THE CONVECTION ASSOCIATED TO THIS FEATURE IS LOCATED OVER THE SE GULF OF MEXICO. A TROPICAL WAVE IS MOVING ACROSS HISPANIOLA WITH AXIS ANALYZED ALONG 71W N OF 16N. THIS WAVE IS GENERATING SCATTERED HEAVY SHOWERS AND THUNDERSTORMS N OF 17N BETWEEN 69W-76W INCLUDING INLAND PORTIONS OF DOMINICAN REPUBLIC...HAITI AND EASTERN CUBA. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED AS THE SYSTEM MOVES WNW OVER THE NEXT 24 HOURS. THIS ACTIVITY COULD GENERATE FLASH FLOODING AND MUDSLIDES OVER SATURATED-HIGH TERRAIN AND RIVERS DURING THE FORECAST PERIOD. SIMILAR ACTIVITY IS OVER THE FAR SW BASIN... WITHIN 70 NM OFF THE COAST OF COSTA RICA...DUE TO CLOSE PROXIMITY TO THE MONSOON TROUGH ANALYZED ACROSS CENTRAL AMERICA THROUGH NORTHERN PANAMA INTO NORTHERN COLOMBIA. FAIR WEATHER CONDITIONS ARE ELSEWHERE ACROSS THE REMAINDER OF THE CARIBBEAN WITH EASTERLY 10-20 KT TRADE WINDS. ATLANTIC OCEAN... A BROAD SURFACE RIDGE DOMINATES THE ATLC DISCUSSION AREA WITH MOSTLY FAIR WEATHER CONDITIONS ANCHORED BY A BROAD AND STRONG 1030 MB HIGH CENTERED OVER THE AZORES NEAR 40N26W. THIS HIGH PRESSURE SYSTEM EXTENDS A RIDGE AXIS SOUTH-WESTWARD TO A 1024 MB HIGH NEAR 30N57W...THEN WESTWARD TO THE FAR W ATLC AND ACROSS THE FLORIDA PENINSULA INTO THE GULF OF MEXICO. HOWEVER...A TROPICAL WAVE MOVING ACROSS HISPANIOLA EXTENDS AXIS TO NEAR THE FAR EASTERN ISLANDS OF THE BAHAMAS ALONG 71W. ALTHOUGH MOS OF THE CONVECTION IS HAPPENING OVER THE N CENTRAL CARIBBEAN AND INLAND PORTIONS OF HISPANIOLA AND EASTERN CUBA...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 90-140 NM ON EITHER SIDE OF THE WAVE AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA