000 AXNT20 KNHC 041738 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUN 04 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. ....SPECIAL FEATURE... BROAD CYCLONIC FLOW COVERS THE CARIBBEAN SEA THIS AFTERNOON...AROUND A 1008 MB LOW CENTERED NEAR 16N78W...120 NM S OF JAMAICA. ACTIVE MONSOON TROUGH EXTENDS SSW FROM THE LOW CENTER TO CENTRAL AMERICA ALONG 11N79W 9N84W. THIS SYSTEM REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE FROM 10N-20N BETWEEN 72W-80W. ENVIRONMENTAL CONDITIONS ARE GENERALLY CONDUCIVE FOR FURTHER DEVELOPMENT. HEAVY RAINS COULD CAUSE FLASH FLOODING AND MUD SLIDES OVER PORTIONS OF HAITI...THE DOMINICAN REPUBLIC... JAMAICA...AND EXTREME SOUTHEASTERN CUBA OVER THE NEXT DAY OR TWO AS THE LOW REMAINS NEARLY STATIONARY OVER THE WEST-CENTRAL CARIBBEAN SEA. THERE IS A MEDIUM CHANCE OF TROPICAL CYCLONE FORMATION DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 16N47W TO 8N52W MOVING WNW 10-15 KT. VISIBLE SATELLITE IMAGERY INDICATED AN INVERTED V STRUCTURE IN THE SOUTHERN PERIPHERY OF THE WAVE AXIS. THE NORTHERN EXTENSION OF THE AXIS IS EMBEDDED WITHIN AN AREA OF DRY AIR AND THUS THE CONVECTION REMAINS TO THE S AFFECTING THE COASTAL WATERS OF GUYANA...SURINAME...AND FRENCH GUIANA S OF 9N. TROPICAL WAVE IS ANALYZED FROM 17N58 TO THE COAST OF VENEZUELA NEAR 10N61W MOVING WNW 10-15 KT. WAVE HAS WELL DEFINED INVERTED V STRUCTURE S OF 12N WITH CLUSTERS OF SCATTERED MODERATE CONVECTION AFFECTING THE COASTAL WATERS OF VENEZUELA WITHIN 90 NM. THE CONVECTION ASSOCIATED WITH THIS WAVE WILL MOVE ACROSS THE WINDWARD ISLANDS LATER THIS AFTERNOON. TROPICAL WAVE IS EMBEDDED IN THE ITCZ...ANALYZED FROM 11N32W TO 6N30W. CONVECTION REMAINS ATTACHED TO ITCZ. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS SENEGAL IN WEST AFRICA...ENTERING THE EAST ATLC NEAR 14N17W TO 8N23W WHERE THE ITCZ CONTINUES TO 7N28W...RESUMING SW OF A TROPICAL WAVE NEAR 6N31W AND CONTINUING W ALONG 4N37W TO 6N51W. SCATTERED MODERATE CONVECTION IS MOVING OFF SW AFRICA FROM 5N-10N E OF 21W TO INLAND OVER SIERRA LEONE AND LIBERIA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 50 NM ON EITHER SIDE OF THE ITCZ AXIS BETWEEN 31W-37W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS OVER THE SW GULF SUPPORTING A WEAKENING 1016 MB SURFACE LOW JUST OFF THE COAST OF MEXICO NEAR 24N97W MOVING INLAND WITH A SURFACE TROUGH EXTENDING SSE TO 20N96W PRODUCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS W OF 95W FROM 20N-25N. A BROAD UPPER RIDGE CENTERED IN THE SE CONUS COVERS THE REMAINDER OF THE GULF WITH DRY STABLE AIR ALOFT PROVIDING FAIR WEATHER CONDITIONS ACROSS THE DISCUSSION AREA. CARIBBEAN SEA... THE PRIMARY FOCUS THIS AFTERNOON IS A 1008 MB LOW SITTING IN THE CENTRAL CARIBBEAN DISCUSSED IN THE SPECIAL FEATURE SECTION ABOVE. BROAD ANTI-CYCLONIC FLOW ALOFT CENTERED IN THE EASTERN CARIBBEAN DOMINATES THE ENTIRE BASIN THIS EARLY AFTERNOON. THIS FEATURE IS PROVIDING A DIFFLUENT ENVIRONMENT ALOFT ENHANCING THE ACTIVITY RELATED TO THE SPECIAL FEATURE LOW BETWEEN 72W-80W INCLUDING THE GREATER ANTILLES. THE SPECIAL FEATURE LOW WILL REMAIN NEARLY STATIONARY OVER THE NEXT FEW DAYS. THE TROPICAL WAVE E OF THE WINDWARD ISLANDS WILL ENTER THE FAR E CARIBBEAN TONIGHT BEFORE BECOMES EMBEDDED IN THE BROAD/ELONGATED TROUGH AXIS EXTENDING ACROSS THE S CENTRAL ATLC INTO THE N CENTRAL CARIBBEAN. ATLANTIC OCEAN... A MID-UPPER LEVEL TROUGH IS OVER THE NW ATLC SUPPORTING A COLD FRONT THAT EXTENDS ALONG THE N PERIPHERY OF THE DISCUSSION AREA ALONG 32N63W 29N71W TO THE COAST OF SOUTH CAROLINA NEAR 32N81W. THIS BOUNDARY IS GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 30 NM S ON EITHER SIDE OF IT. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 30N62W TO 28N65W WITH SCATTERED SHOWERS WITHIN 120 NM E OF THE TROUGH. DRY STABLE AIR COVERS THE REMAINDER OF THE W ATLC LEAVING THE AREA N OF 23N W OF 57W UNDER CLEAR SKIES THIS AFTERNOON. SURFACE CONVERGENCE AND UPPER LEVEL DIFFLUENCE IS OBSERVED ALONG A MID-UPPER LEVEL TROUGH AXIS EXTENDING ACROSS THE S CENTRAL ATLC INTO THE N CENTRAL CARIBBEAN...GENERATING SCATTERED SHOWERS AND THUNDERSTORMS FROM 19N-25N BETWEEN 50W-63W. THIS ACTIVITY IS FURTHER SUPPORTED ALOFT BY A WEAK JET STREAK WITH AXIS FROM 28N50W TO 23N65W. SURFACE RIDGING DOMINATES THE REMAINDER OF THE CENTRAL AND E ATLC E OF 47W PROVIDING MOSTLY FAIR WEATHER ACROSS THE AREA. THE COLD FRONT OVER THE W ATLC WILL MOVE INTO THE CENTRAL ATLC BY TONIGHT AS WEAK SURFACE RIDGE BUILDS S OVER THE FAR W ATLC AND THE GULF OF MEXICO. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA