000 AXNT20 KNHC 041152 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1145 UTC. ....SPECIAL FEATURE... A BROAD AREA OF LOW PRESSURE ROUGHLY CENTERED 100 NM S OF JAMAICA WITH A SURFACE TROUGH EXTENDING S TO THE PANAMA CANAL REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER. SCATTERED/HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS ARE E OF THE LOW CENTER WITHIN 120/150 NM OF LINE FROM HAITI NEAR 20N72W TO 10N77W AND SCATTERED SHOWERS COVERING A BROADER AREA N OF 17N TO ACROSS THE GREATER ANTILLES BETWEEN 63W-78W AND S OF 17N BETWEEN 70W-84W. 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 ALONG 44W S OF 17N MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DRY AIR AND THUS NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 58W S OF 14N MOVING W 10-15 KT. WAVE IS WELL DEFINED S OF 12N WITH CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 8N-12N BETWEEN 55W-61W. SHOWERS ASSOCIATED WITH THIS WAVE WILL MOVE ACROSS THE WINDWARD ISLANDS LATER THIS AFTERNOON. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E ATLC NEAR 16N16W TO 8N23W WHERE THE ITCZ CONTINUES ALONG 4N36W 5N53W. SCATTERED/NUMEROUS STRONG CONVECTION IS MOVING OFF SW AFRICA FROM 7N-11N E OF 17W TO INLAND OVER SIERRA LEONE AND GUINEA. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 2N-8N W OF 47W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS OVER THE SW GULF NEAR 24N95W SUPPORTING A WEAKENING 1014 MB SURFACE LOW THAT CONTINUES TO MOVE W AND IS CENTERED AT 04/0900 UTC NEAR 25N96W WITH A SURFACE TROUGH EXTENDING S TO 21N95W PRODUCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 23N-25N BETWEEN 93W-97W AND SCATTERED SHOWERS WITHIN 45 NM E OF THE SURFACE TROUGH. A BROAD UPPER RIDGE COVERS THE SE CONUS TO OVER THE N GULF N OF 26N ANCHORED OVER THE LOWER MISSISSIPPI VALLEY AND A SECOND UPPER RIDGE COVERS THE SE GULF ANCHORED IN THE CARIBBEAN WITH DRY STABLE AIR ALOFT COVERING MUCH OF THE GULF. A WEAK SURFACE RIDGE CONTINUES TO DOMINATE THE N GULF WITH A 1019 MB HIGH LOCATED NEAR THE MISSISSIPPI DELTA AT 04/0900 UTC. A SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN INLAND OVER THE N GULF COAST AND CONTINUES TO PRODUCE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 30 NM OF LINE FROM NE FLORIDA NEAR JACKSONVILLE INTO THE GULF NEAR PANAMA CITY TO INLAND OVER SE LOUISIANA NEAR NEW ORLEANS LEAVING THE REMAINDER OF THE GULF UNDER CLEAR SKIES THIS MORNING. THE SURFACE LOW WILL CONTINUE TO MOVE WEST REACHING THE COAST OF MEXICO LATER TODAY. THE SURFACE RIDGE WILL DRIFT S REACHING TO ALONG 26N EARLY NEXT WEEK. CARIBBEAN SEA... THE PRIMARY FOCUS THIS MORNING IS THE AREA OF LOWER PRESSURE DISCUSSED IN THE SPECIAL FEATURES ABOVE. A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED IN THE E CARIBBEAN NEAR 13N65W. THIS UPPER RIDGE IS PROVIDING A DIFFLUENT ENVIRONMENT ALOFT ENHANCING THE ACTIVITY DESCRIBED IN THE SPECIAL FEATURES. THE SPECIAL FEATURE LOW WILL REMAIN NEARLY STATIONARY THROUGH EARLY NEXT WEEK. THE TROPICAL WAVE E OF THE WINDWARD ISLANDS WILL ENTER THE FAR E CARIBBEAN TONIGHT AND INTO EARLY SUN BEFORE LIFTING NE AS A TROUGH MON THROUGH WED AND COULD BRING SHOWERS TO THE ISLANDS THIS AFTERNOON. ATLANTIC OCEAN... AN UPPER TROUGH IS OVER THE NW ATLC N OF 25N W OF 57W TO THE FLORIDA PENINSULA SUPPORTING A COLD FRONT THAT EXTENDS ALONG THE N PERIPHERY OF THE DISCUSSION AREA ALONG 32N62W 31N67W TO 31N73W WHERE IT BECOMES STATIONARY TO INLAND OVER THE SE CONUS NEAR SAVANNAH GEORGIA AT 04/0600 UTC PRODUCING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 60 NM S OF THE COLD FRONT. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 31N63W TO 29N71W WITH ISOLATED SHOWERS WITHIN 60 NM SE OF THE TROUGH E OF 67W. DRY STABLE AIR COVERS THE REMAINDER OF THE W ATLC LEAVING THE AREA N OF 25N UNDER CLEAR SKIES THIS MORNING. THE BROAD UPPER RIDGE OVER THE CARIBBEAN EXTENDS AN AXIS N OVER THE CENTRAL ATLC ACROSS THE N LEEWARD ISLANDS NEAR 17N62W TO 28N52W PROVIDING A DIFFLUENT ENVIRONMENT ALOFT ENHANCING SCATTERED SHOWERS WITHIN 250 NM OF LINE FROM ACROSS THE GREATER ANTILLES NEAR 19N69W TO 24N48W. A NARROWING UPPER TROUGH EXTENDS THROUGH 32N53W SE TO 22N42W WITH A SURFACE TROUGH EXTENDING FROM 27N52W TO 29N42W AND SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 27N42W TO BEYOND 32N47W. A SURFACE RIDGE DOMINATES THE CENTRAL AND E ATLC E OF 50W WITH A WEAKNESS IN THE VICINITY OF THE ABOVE SURFACE TROUGH AND PROVIDING MOSTLY FAIR WEATHER ACROSS THE E ATLC. 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 $$ PAW/FG