000 AXNT20 KNHC 121043 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 12 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... A 1010 MB LOW IS CENTERED ABOUT 1000 NM W OF THE CAPE VERDE ISLANDS NEAR 13N40W WITH A TROPICAL WAVE EXTENDING NW FROM THE LOW TO 20N44W. THE SYSTEM IS MOVING W AT 13 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 16N-19N BETWEEN 41W-46W. SATELLITE IMAGERY SUGGESTS THE SYSTEM MAY BE ENCOUNTERING A DRIER AND MORE STABLE AIR MASS...HOWEVER ENVIRONMENTAL CONDITIONS STILL APPEAR FAVORABLE FOR GRADUAL DEVELOPMENT OVER THE NEXT SEVERAL DAYS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. A 1010 MB LOW IS CENTERED ABOUT 275 NM SSW OF THE CAPE VERDE ISLANDS NEAR 11N27W WITH A TROPICAL WAVE EXTENDING N ACROSS THE CAPE VERDE ISLANDS TO 17N25W. HE SYSTEM IS MOVING W AT 13-17 KT. WIDELY SCATTERED MODERATE CONVECTION IS NEAR THE LOW CENTER FROM 8N-14N BETWEEN 27W-33W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO GRADUALLY BECOME MORE CONDUCIVE FOR DEVELOPMENT OVER THE NEXT SEVERAL DAYS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN FROM 20N78W TO 12N80W MOVING W 10 KT. THE WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS OVER E CUBA FROM 18N-20N BETWEEN 75W-77W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS OFF THE W COAST OF AFRICA NEAR 21N16W AND CONTINUES TO THE LOW AT 11N27W THEN CONTINUES TO 14N34W. THE ITCZ EXTENDS FROM 14N34W TO THE LOW AT 13N40W TO SOUTH AMERICA NEAR 4N51W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS OVER FLORIDA FROM JACKSONVILLE TO S OF MIAMI. SCATTERED SHOWERS ARE OVER THE STRAITS OF FLORIDA. A 1015 MB HIGH IS CENTERED OVER THE E GULF OF MEXICO NEAR 24N85W. 5-10 KT ANTICYCLONIC SURFACE WINDS ARE NOTED WITH MOSTLY FAIR WEATHER. CLUSTERS OF WIDELY SCATTERED MODERATE CONVECTION ARE INLAND OVER S MEXICO. IN THE UPPER LEVELS AN UPPER LEVEL HIGH IS CENTERED OVER THE W GULF NEAR 26N92W WITH STRONG SUBSIDENCE. UPPER LEVEL MOISTURE IS NOTED OVER S FLORIDA...W CUBA...AND THE SE GULF. EXPECT...LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. SEE ABOVE. THE MONSOON TROUGH EXTENDS FROM N COLOMBIA TO PANAMA AND COSTA RICA GENERATING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION S OF 12N. WIDELY SCATTERED MODERATE CONVECTION IS INLAND OVER NICARAGUA...HONDURAS...EL SALVADOR...AND GUATEMALA. 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. ATLANTIC OCEAN... A 1019 MB HIGH IS CENTERED N OF THE LEEWARD ISLANDS NEAR 26N65W PRODUCING FAIR WEATHER. A 1014 MB LOW IS FURTHER E NEAR 25N54W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO 20N58W. ISOLATED MODERATE CONVECTION IS WITHIN 45 NM OF THE TROUGH AXIS. A 1025 MB HIGH IS CENTERED S OF THE AZORES NEAR 36N30W. A SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 23N48W. EXPECT THE TWO SPECIAL FEATURE LOWS TO BE THE DOMINATE WEATHER PRODUCERS OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA