000 AXNT20 KNHC 290006 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE AUG 28 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... HURRICANE ISAAC IS CENTERED NEAR 29.0N 89.4W AT 29/0000 UTC ABOUT 10 MILES SW OF THE MOUTH OF THE MISSISSIPPI RIVER... OR ABOUT 90 MILES SE OF NEW ORLEANS LOUISIANA MOVING NW AT 7 KT. MINIMUM CENTRAL PRESSURE IS 970 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. SEE THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER OF ISAAC. ISAAC HAS MADE LANDFALL IN EXTREME SOUTHEASTERN LOUISIANA. ISAAC IS FORECAST TO GRADUALLY WEAKEN AS IT MOVES INLAND. THE MAIN THREATS ASSOCIATED WITH ISAAC WILL BE VERY HEAVY RAINFALL OVER THE N GULF COAST STATES...DANGEROUS STORM SURGE AND SURF CONDITIONS... AND STRONG WINDS WELL AWAY FROM THE CENTER AS THE OVERALL CIRCULATION OF ISAAC IS QUITE LARGE. FOR MORE DETAILED INFORMATION REFER TO HURRICANE LOCAL STATEMENTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE. TROPICAL DEPRESSION ELEVEN IS CENTERED NEAR 23.8N 43.9W AT 15/2100 UTC ABOUT 1270 MI...2045 KM ENE OF THE LESSER ANTILLES ...OR ABOUT 1400 MI...2250 KM SW OF THE AZORES MOVING WNW AT 9 KT. MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION IS N OF THE CENTER FROM 23N-26N BETWEEN 41W-46W. A TROPICAL WAVE EXTENDS FROM 17N26W TO LOW PRES NEAR 12N29W 1010 MB. THE SYSTEM IS WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS MOVING W AT 15-20 KT. SCATTERED MODERATE CONVECTION IS NW OF THE LOW CENTER FROM 13N-16N BETWEEN 28W-34W. THIS SYSTEM HAS BECOME BETTER ORGANIZED TODAY...AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR SLOW DEVELOPMENT DURING THE NEXT COUPLE OF DAYS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS. SEE ABOVE. ...ITCZ/MONSOON TROUGH... A MONSOON TROUGH IS SW OF THE LOW CENTERED NEAR 12N29W. IT EXTENDS FROM 10N30W TO 9N42W. AN ITCZ IS FURTHER W FROM 15N50W TO TRINIDAD AT 10N61W. SCATTERED MODERATE CONVECTION IS FROM 7N-12N BETWEEN 33W-37W...AND FROM 13N-15N BETWEEN 55W-58W. ...DISCUSSION... GULF OF MEXICO... THE DOMINATE FEATURE IN THE GULF OF MEXICO IS HURRICANE ISAAC NEAR THE MOUTH OF THE MISSISSIPPI RIVER WITH THE LARGE CIRCULATION COVERING MOST OF THE NORTHERN GULF OF MEXICO. SCATTERED MODERATE CONVECTION IS OVER INLAND CENTRAL AND NORTHERN FLORIDA N OF 26N BETWEEN 80W-82W. THE BAY OF CAMPECHE IS THE ONLY AREA WITH FAIR WEATHER. PLEASE REFER TO THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS ABOUT ISAAC. AT THE UPPER LEVELS...A MID TO UPPER LOW IS NEAR THE NE MEXICAN COAST AT 24N101W AND IT IS MOVING WESTWARD TOWARD CENTRAL MEXICO. DRY AND STABLE AIR EXTENDS FROM THIS LOW TO THE SW GULF. A NEARLY STATIONARY UPPER LEVEL RIDGE IS N OF ISSAC ALONG THE N GULF COAST STATES FROM TEXAS NEAR 31N99W TO SOUTHERN ALABAMA NEAR 32N87W TO CENTRAL FLORIDA NEAR 27N81W. DRY AIR ALONG THE SOUTHERN PERIPHERY OF THE RIDGE IS ADVECTING INTO THE CIRCULATION OF ISAAC HELPING TO LIMIT ADDITIONAL DEVELOPMENT AND INTENSIFICATION. EXPECT... ATLANTIC HIGH PRESSURE TO BUILD INTO THE AREA FROM THE W IN THE WAKE OF ISAAC LATE WED THROUGH THE END OF THE WEEK WITH MODERATE TO FRESH SE-S RETURN FLOW BECOMING ESTABLISHED ACROSS THE GULF BY FRI. CARIBBEAN SEA... 15-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. SCATTERED MODERATE TO STRONG CONVECTION IS INLAND OVER N NICARAGUA...HONDURAS...EL SALVADOR...AND GUATEMALA. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE REMAINDER OF CENTRAL AMERICA TO INCLUDE PANAMA...COSTA RICA...AND THE YUCATAN PENINSULA. OVER THE CARIBBEAN WIDELY SCATTERED MODERATE CONVECTION IS S OF CUBA FROM 17N-21N BETWEEN 78W-83W. ISOLATED MODERATE CONVECTION IS ALONG THE COAST OF HAITI FROM 17N-19N BETWEEN 70W-73W. SIMILAR CONVECTION IS OVER THE WINDWARD ISLANDS FROM 12N-15N BETWEEN 60W-65W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED NEAR JAMAICA AT 18N75W INFLUENCING THE DIRECTION OF THUNDERSTORM FLOW OVER HAITI AND CUBA. EXPECT CONTINUED CONVECTION OVER THE W CARIBBEAN AND CENTRAL AMERICA OVER THE NEXT 24 HOURS. ALSO EXPECT CONTINUED CONVECTION OVER THE WINDWARD ISLANDS. ATLANTIC OCEAN... 1021 MB SURFACE HIGH PRES IS S OF BERMUDA NEAR 29N56W WITH A RIDGE AXIS REACHING TO THE W-NW TO SE GEORGIA. LIGHT TO MODERATE WINDS DOMINATE THE WATERS W OF 50W WITH A CLUSTER OF SCATTERED SHOWERS AND TSTMS N OF HISPANIOLA TO ACROSS THE TURKS AND CAICOS...WITH ADDITIONAL CONVECTION E OF FLORIDA TO 77W. THE OTHER MAIN FEATURES IN THE ATLC ARE T.D. ELEVEN...AND THE TROPICAL WAVE AND ASSOCIATED LOW...DISCUSSED IN THE SPECIAL FEATURES SECTION. AN UPPER LEVEL ANTICYCLONE IS NEAR 22N31W WITH AN UPPER RIDGE REACHING FROM 23N25W THROUGH THE ANTICYCLONE TO 21N67W. UPPER LEVEL EASTERLIES DOMINATE THE REGION S OF 20N ON THE SOUTHERN PERIPHERY OF THE ANTICYCLONE/RIDGE. OTHERWISE...AN UPPER LEVEL LOW IS E OF THE RIDGE NEAR 24N20W. DRY AIR COVERS THE WATERS N OF 24N E OF 25W. AN UPPER LEVEL TROUGH EXTENDS FROM 32N42W TO 27N50W AND THIS FEATURE IS SUPPORTING A SURFACE COLD FRONT N OF 32N...AS WELL AS A SURFACE TROUGH THAT REACHES NE FROM THE LOW IN THE SPECIAL FEATURES SECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA