000 AXNT20 KNHC 131153 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT AUG 13 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 1045 UTC. ...SPECIAL FEATURES... TROPICAL STORM FRANKLIN IS CENTERED NEAR 37.9N 60.4W AT 13/0900 UTC 0R ABOUT 460 MI...740 KM NNE OF BERMUDA MOVING NE AT 17 KT. ESTIMATED CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUST TO 45 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 37N-40N BETWEEN 58W-61W. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. A 1013 MB LOW IS CENTERED NEAR 20N50W IS MOVING WNW AT 18 KT. THE SYSTEM HAS BECOME A LITTLE BETTER DEFINED OVER THE PAST COUPLE OF HOURS...BUT UPPER-LEVEL CONDITIONS ARE ONLY MARGINALLY FAVORABLE FOR FURTHER DEVELOPMENT. THERE REMAINS THE POTENTIAL FOR SLOW DEVELOPMENT OF THIS SYSTEM...AND IT HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. SURFACE TROUGH LOCATED NORTH-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS EXTENDS FROM 30N58W TO A 1013 MB LOW NEAR 26N58W TO 23N61W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 60 NM OF THE TROUGH AXIS. CONTINUED SLOW DEVELOPMENT IS POSSIBLE DURING THE NEXT COUPLE OF DAYS AS THE LOW MOVES WNW NEAR 10-12 KT. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A 1011 MB LOW IS OVER THE E ATLANTIC OVER THE E ATLANTIC ABOUT 650 MILES WEST-SOUTHWEST OF THE SOUTHERN CAPE VERDE ISLANDS AT 12N34W. A TROPICAL WAVE EXTENDS N FROM THE LOW TO 17N36W. ONLY LIMITED SHOWER ACTIVITY IS NOTED. THE SYSTEM IS MOVING W AT 13-18 KT. TROPICAL WAVE IN THE W CARIBBEAN IS ANALYZED ALONG 84W FROM 12N-21N MOVING W 10-15 KT. WAVE REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS S OF CUBA TO NICARAGUA FROM 13N-22N BETWEEN 81W-85W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS INTO THE E TROPICAL ATLC OFF W AFRICA NEAR 18N17W AND CONTINUES SW TO 14N26W. THE ITCZ EXTENDS FROM 14N26W TO THE LOW AT 12N34W TO SOUTH AMERICA NEAR 9N61W. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF WEST AFRICA FROM 5N-8N BETWEEN 15W-23W. SCATTERED SHOWERS ARE FROM 7N-17N BETWEEN 33W-41W. ...DISCUSSION... GULF OF MEXICO... SCATTERED SHOWERS ARE INLAND OVER FLORIDA FROM COCOA BEACH TO FORT MYERS. WEAK SURFACE RIDGING IS OVER THE NE GULF OF MEXICO. 5-10 KT ANTICYCLONIC SURFACE WINDS ARE NOTED WITH MOSTLY FAIR WEATHER. CLUSTERS OF WIDELY SCATTERED MODERATE CONVECTION ARE OVER THE SOUTHERN BAY OF CAMPECHE AND OVER S MEXICO S OF 20N. IN THE UPPER LEVELS AN UPPER LEVEL HIGH IS CENTERED OVER TEXAS NEAR 30N100W. STRONG SUBSIDENCE IS OVER THE W GULF W OF 90W. UPPER LEVEL MOISTURE IS NOTED OVER FLORIDA...W CUBA...AND THE SE GULF. EXPECT...LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN. SEE ABOVE. THE MONSOON TROUGH EXTENDS FROM N COLOMBIA TO PANAMA AND COSTA RICA GENERATING SCATTERED SHOWERS S OF 12N. ISOLATED MODERATE CONVECTION IS INLAND OVER HONDURAS... AND EL SALVADOR. 15-20 KT TRADEWINDS ARE NOTED OVER THE CARIBBEAN WITH STRONGEST WINDS OVER THE CENTRAL CARIBBEAN N OF COLOMBIA. EXPECT THE TROPICAL WAVE TO ENHANCE CONVECTION OVER THE W CARIBBEAN AND CENTRAL AMERICA OVER THE NEXT 24 HOURS. ALSO EXPECT TROPICAL MOISTURE WITH CONVECTION TO ALSO ADVECT OVER THE LEEWARD ISLANDS AND PUERTO RICO. ATLANTIC OCEAN... BESIDES THE THREE SYSTEMS MENTIONED IN THE SPECIAL FEATURE SECTION...A 1019 MB HIGH IS CENTERED N OF THE LEEWARD ISLANDS NEAR 28N66W PRODUCING FAIR WEATHER. A 1024 MB HIGH IS CENTERED SW OF THE AZORES NEAR 33N39W. A SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 27N50W ALSO PRODUCING FAIR WEATHER. EXPECT THE SPECIAL FEATURE LOWS AND TROPICAL WAVE TO BE THE DOMINATE WEATHER PRODUCERS OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA