000 AXNT20 KNHC 301756 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 30 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 1745 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM ISAAC AT 30/1800 UTC IS NEAR 32.2N 92.3W. ISAAC HAS BEEN INLAND FOR OVER 24 HOURS. THE CURRENT POSITION IS ABOUT 25 MI SW OF MONROE LOUISIANA. ISAAC IS MOVING NNW AT 8 KNOTS. THE MINIMUM CENTRAL PRESSURE IS 992 MB WITH MAXIMUM SUSTAINED WIND SPEEDS OF 35 KNOTS GUSTING TO 45 KNOTS. PLEASE READ THE NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC AND THE PUBLIC ADVISORY... MIATCPAT4 /WTNT34 KNHC FOR MORE DETAILS. THE RESULTANT BROAD CYCLONIC CIRCULATION CONTINUES TO IMPACT THE N-CENTRAL AND N-ERN GULF THIS AFTERNOON. MOST OF THE ENERGY LEFT IN THIS SYSTEM IS CONCENTRATED E AND SE OF THE CENTER...WHERE SEVERAL CONVECTIVE BANDS ARE NOTED ON DOPPLER RADAR IMAGERY N OF 25N BETWEEN 85W-93W. EVEN THOUGH ISAAC IS NO LONGER A HURRICANE...LIFE THREATENING HAZARDS FROM STORM SURGE...INLAND FLOODING...AND TORNADOES ARE STILL OCCURRING. ALL RESIDENTS IN LOUISIANA... MISSISSIPPI...AND SURROUNDING STATES SHOULD CONTINUE TO MONITOR ALL BULLETINS THAT ARE ISSUED BY THE NATIONAL HURRICANE CENTER AND THE LOCAL NATIONAL WEATHER SERVICE OFFICES FOR UPDATES ABOUT THIS SYSTEM. TROPICAL STORM KIRK WAS UPGRADED TO HURRICANE STATUS AT 30/1500 UTC...LOCATED NEAR 27.2N 49.5W. KIRK IS MOVING NW 10 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 65 KT WITH GUSTS TO 80 KT. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND THE PUBLIC ADVISORY...MIATCPAT1/ WTNT31 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION EXTENDS UP TO 100 NM FROM THE CENTER AT ALL QUADRANTS. THE SPECIAL FEATURE LOW PRESSURE SYSTEM AND ASSOCIATED TROPICAL WAVE OVER THE CENTRAL TROPICAL ATLC BECAME TROPICAL DEPRESSION TWELVE AT 30/1500 UTC...CENTERED NEAR 14.1N 43.4W. THIS SYSTEM IS MOVING NW AT ABOUT 7 KT WITH GUSTY WINDS UP TO 40 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 10N-17N BETWEEN 42W-48W. THIS SYSTEM IS MOVING INTO A REGION OF FAVORABLE DEVELOPMENT AND GLOBAL MODEL GUIDANCE SUGGEST IT COULD BECOME STRONGER OVER THE NEXT 24 HOURS. ...TROPICAL WAVES... NO TROPICAL WAVES ARE INCLUDED IN THE 30/1200 UTC SURFACE MAP ANALYSIS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS INLAND ACROSS WEST AFRICA TO THE COAST OF SIERRA LEONE AT 8N13W CONTINUING WNW TO 11N28W. THE MONSOON TROUGH BEGINS AGAIN SOUTH OF TROPICAL DEPRESSION TWELVE FROM 12N43W ALONG TO 9N53W. GIVEN THE BROAD CIRCULATION OF THIS SYSTEM...NO OCEANIC ITCZ AXIS IS PRESENT. SCATTERED WEAK TO ISOLATED MODERATE CONVECTION IS FROM 4N-9N E OF 30W. ...DISCUSSION... THE GULF OF MEXICO... ALTHOUGH THE CENTER OF TROPICAL STORM ISAAC IS WELL INLAND OVER THE STATE OF LOUISIANA...THE RESULTANT BROAD CYCLONIC CIRCULATION CONTINUES TO IMPACT THE N-CENTRAL AND N-ERN GULF THIS AFTERNOON. MOST OF THE ENERGY LEFT IN THIS SYSTEM IS CONCENTRATED E AND SE OF THE CENTER...WHERE SEVERAL CONVECTIVE BANDS ARE NOTED ON DOPPLER RADAR IMAGERY N OF 25N BETWEEN 85W-93W. MARINE OBSERVATIONS SHOW GUSTY SOUTHERLY WINDS UP TO 40 KT IN THIS AREA. THIS SOUTHERLY FLOW ALONG WITH LOW LEVEL MOISTURE DRAWN ACROSS THE SE IS ADVECTING SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE YUCATAN CHANNEL. FAIR WEATHER IS ELSEWHERE ACROSS THE GULF ATTRIBUTED TO DRY AIR ALOFT WRAPPING AROUND ISAAC. STORMY CONDITIONS WILL REMAIN ACROSS A LARGE PORTION OF THE N-CENTRAL GULF FOR AT LEAST THE NEXT 24 HOURS. INTERESTS IN THESE REGION SHOULD MONITOR THE PROGRESS OF ISAAC. THE CARIBBEAN SEA... AN ELONGATED UPPER LOW MOVES ACROSS THE NW CARIBBEAN ON WATER VAPOR IMAGERY...CURRENTLY CENTERED NEAR 20N82W. THIS FEATURE IS PROVIDING AN AREA OF STRONG DIFFLUENCE ALOFT OVER THE FAR SW... GENERATING SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS W OF 80W. SOME OF THE ACTIVITY IN THIS REGION S OF 13N IS ALSO SUPPORTED BY THE ERN PACIFIC MONSOON TROUGH EXTENDING INTO THE SW CARIBBEAN ACROSS COSTA RICA TO NRN COLOMBIA. THIS AREA OF CONVECTION IS BEING DRAWN NORTHWARD ACROSS THE YUCATAN CHANNEL INTO THE GULF OF MEXICO...IN RESPONSE OF THE BROADER/STRONGER FLOW AROUND TROPICAL STORM ISAAC. A WEAK/SLOW MOVING SURFACE TROUGH IS NOTED A FEW MILES E OF THE LESSER ANTILLES ANALYZED FROM 15N60W TO TRINIDAD AND TOBAGO. THIS FEATURE IS GENERATING A CLUSTER OF MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS OVER THE ISLANDS OF MARTINIQUE...ST LUCIA...ST VINCENT...AND BARBADOS. THIS SYSTEM WILL CONTINUE TO DRIFT WESTWARD DURING THE NEXT 24 HOURS WITH THE POTENTIAL FOR COASTAL FLOODING AND MUDSLIDES OVER HIGHER TERRAIN OVER THIS GROUP OF ISLANDS. OTHERWISE...THE REMAINDER OF THE DISCUSSION AREA IS DOMINATED BY DRY AIR ALOFT NOTED ON WATER VAPOR IMAGERY...PROVIDING MOSTLY FAIR WEATHER CONDITIONS WITH A FEW ISOLATED LOW-TOP SHOWERS ACROSS THE AREA. MODERATE TO FRESH TRADEWIND FLOW IS ACROSS MUCH OF THE CENTRAL AND EASTERN PORTIONS OF THE BASIN E OF 80W. THE ATLANTIC OCEAN... A FRONTAL BOUNDARY EXTENDS ALONG OUR NRN FRINGE OF OUR DISCUSSION AREA ALONG LATITUDE 32N W OF 63W...GENERATING WIDELY SCATTERED SHOWERS N OF 27N BETWEEN 70W-79W. SHORT RANGE COMPUTER MODELS SUGGEST THE FRONT WILL EXPAND SE INTO OUR AREA WITH ISOLATED MODERATE CONVECTION. ASIDE HURRICANE KIRK AND NEWLY FORMED TROPICAL DEPRESSION TWELVE...THE REMAINDER OF THE ATLC BASIN DISCUSSION AREA IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 26N60W...AND A BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED W OF THE IBERIAN PENINSULA. THE OVERALL ACTIVITY IS ENHANCED ALOFT BY SAHARAN DUST NOTED ON GOES-R IMAGERY AND METEOSAT-9 SAL PRODUCT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA