000 AXNT20 KNHC 231809 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 23 2012 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 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM ISAAC AT 23/1800 UTC IS NEAR 16.0N 66.4W... MOVING WNW AT 13 KNOTS. THIS POSITION IS ABOUT 165 MI/255 KM S OF SAN JUAN PUERTO RICO...OR ABOUT 275 MI...445 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC. THE MINIMUM CENTRAL PRESSURE IS 1003 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC AND THE PUBLIC ADVISORY... MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 11N-17N BETWEEN 62W-70W. TROPICAL STORM JOYCE AT 23/1500 UTC IS NEAR 15.2N 42.2W...MOVING WNW AT 15 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE READ THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC AND THE PUBLIC ADVISORY...MIATCPAT5/WTNT35 KNHC FOR MORE DETAILS. JOYCE IS EXPERIENCING SOUTHERLY WIND SHEAR AND AN INTRUSION OF DUSTY DRY AIR. SCATTERED MODERATE TO STRONG CONVECTION IS MOSTLY N OF THE CENTER FROM 16N-20N BETWEEN 40W-45W. ...TROPICAL WAVES... A 1010 MB LOW IS OFF THE COAST OF SENEGAL NEAR 14N18W. A TROPICAL WAVE EXTENDS FROM 21N16W TO THE LOW CENTER. THE SYSTEM IS MOVING WSW AT 15 KT. WIDELY SCATTERED MODERATE CONVECTION IS FROM 10N-19N BETWEEN 15W-24W. ...THE ITCZ/THE MONSOON TROUGH... THE ITCZ/THE MONSOON TROUGH IS PRESENTLY BEING DISRUPTED BY THE LOW OFF SENEGAL...TROPICAL STORM JOYCE...AND TROPICAL STORM ISAAC. SCATTERED MODERATE CONVECTION IS HOWEVER E OF TRINIDAD FROM 10N-13N BETWEEN 58W-62W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 1500 UTC... A 1021 MB HIGH DEVELOPED OVER THE NE GULF OF MEXICO NEAR 29N84W. 10-15 KT E-SE SURFACE WINDS ARE OVER THE E GULF WHILE 10-15 SE WINDS REMAIN OVER THE W GULF. ISOLATED MODERATE CONVECTION LINGER OVER THE W GULF NEAR TAMPICO MEXICO FROM 20N-24N BETWEEN 94W-98W. IN THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE N GULF N OF 27N. UPPER LEVEL DIFFLUENCE W OF THE TROUGH IS PRODUCING SCATTERED MODERATE CONVECTION OVER THE NW GULF FROM 25N-29N BETWEEN 87W-97W. EXPECT CONTINUED CONVECTION OVER THE NW GULF OVER THE NEXT 24 HOURS. ALSO EXPECT TROPICAL MOISTURE TO ADVECT OVER W CUBA AND THE STRAITS OF FLORIDA OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... T.S.ISAAC IS PRODUCING CONSIDERABLE CONVECTION OVER THE E CARIBBEAN. SEE ABOVE. HURRICANE AND TROPICAL STORM WARNINGS ARE IN EFFECT FOR PORTIONS OF THE CARIBBEAN. A 1008 MB LOW IS ALSO OVER W VENEZUELA AT 8N71W. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE SW CARIBBEAN...N COLOMBIA...AND PANAMA FROM 8N-11N BETWEEN 72W-83W. 10-15 KT TRADEWINDS ARE OVER THE NW CARIBBEAN. EXPECT T.S. ISAAC TO BE THE DOMINATE WEATHER SYSTEM OVER THE CENTRAL AND EASTERN CARIBBEAN OVER THE NEXT 24 HOURS. ALSO EXPECT MORE CONVECTION OVER THE SW CARIBBEAN AND CENTRAL AMERICA. THE ATLANTIC OCEAN... A 1023 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 34N40W. A SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 29N70W. AFRICAN DUST EXTENDS FROM 10N-34N E OF 33W...AND FROM 10N-27N BETWEEN 33W-65W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER THE BAHAMAS NEAR 23N77W. UPPER LEVEL DIFFLUENCE E OF THE CENTER IS PRODUCING SCATTERED SHOWERS ARE OVER THE S BAHAMAS. ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 21N50W. UPPER LEVEL DIFFLUENCE N OF THE CENTER IS PRODUCING SCATTERED MODERATE CONVECTION ARE OVER THE CENTRAL ATLANTIC FROM 28N-31N BETWEEN 54W-57W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA