000 AXNT20 KNHC 071802 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE SEP 07 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...SPECIAL FEATURE... TROPICAL STORM HERMINE IS CENTERED INLAND OVER SOUTHERN TEXAS NEAR 29.3N 98.4W AT 07/1800 UTC...OR ABOUT 15 MI SSE OF SAN ANTONIO TEXAS MOVING N AT 17 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUST TO 45 KT. PLEASE SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. HEAVY RAIN WITH EMBEDDED ISOLATED THUNDERSTORMS ARE INLAND OVER CENTRAL AND SE TEXAS...WITH THE POSSIBILITY OF ISOLATED TORNADOES DEVELOPING IN THESE REGIONS. THE BANDS ASSOCIATED TO THE SYSTEM CONTINUE TO AFFECT THE NW GULF N OF 23N W OF 94W. WATER LEVELS ALONG THE TEXAS COAST ARE GRADUALLY RECEDING..BUT WILL LIKELY REMAIN ABOVE NORMAL FOR THE NEXT DAY OR TWO. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE FAR EASTERN TROPICAL ATLANTIC BASIN...ANALYZED ALONG 21W S OF 18N MOVING WEST 10-15 KT. SATELLITE DERIVED WINDS INDICATE BROAD CYCLONIC TURNING AROUND THE WAVE AXIS CENTERED NEAR 14N. THIS WAVE IS EMBEDDED IN A SURGE OF DEEP LEVEL MOISTURE AS INDICATED ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS BETWEEN THE COAST OF WEST AFRICA AND 26W FROM 8N TO 18N. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM 11N24W CONTINUING WESTWARD ALONG 10N35W 11N45W 10N55W 12N65W. SCATTERED MODERATE TO STRONG CONVECTION IS BETWEEN THE COAST OF WEST AFRICA AND 26W FROM 8N TO 17N. THIS AREA OF CONVECTION IS ALSO ASSOCIATED WITH A TROPICAL WAVE ALONG 21W S OF 18N. SIMILAR CONVECTION IS SOUTH OF THE ITCZ FROM 4N TO 8N BETWEEN 23W AND 36W...ASSOCIATED WITH THE MONSOONAL TROUGHINESS IN THE EASTERN TROPICAL ATLC E OF 36W. ...DISCUSSION... GULF OF MEXICO... ALTHOUGH TROPICAL STORM HERMINE HAS MOVED INLAND OVER SOUTHERN TEXAS...THE BANDS ASSOCIATED TO THE SYSTEM CONTINUE TO BE THE PRIMARY FOCUS THIS AFTERNOON FOR THE NW GULF OF MEXICO. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ELSEWHERE E OF 93W...A LONGWAVE UPPER LEVEL TROUGH EXTENDS ACROSS THE NE GULF AND NORTHERN HALF OF THE FLORIDA PENINSULA NOTED BY STRONG SUBSIDENCE ALOFT ON WATER VAPOR IMAGERY. THIS UPPER LEVEL FEATURE IS GENERATING SCATTERED SHOWERS OVER THE SOUTHEASTERN HALF OF THE GULF S OF 27N E OF 88W. STRONGER SHOWERS AND THUNDERSTORMS ARE OVER THE FLORIDA STRAITS MOVING WESTWARD INTO THE GULF. COMPUTER MODELS SUGGEST THAT THE UPPER LEVEL SCENARIO WILL CONTINUE TO GENERATE CONVECTION IN THE EASTERN REGION OF THE GULF S OF 28N E OF 87W OVER THE NEXT 24 TO 48 HRS...WITH THE STRONGEST CONVECTION ACROSS THE FLORIDA STRAITS. CARIBBEAN SEA... THE REMNANT 1010 MB LOW PRESSURE CENTER OF GASTON IS ABOUT 130 NM SE OF THE ISLAND OF PUERTO RICO NEAR 17N63W. A SURFACE TROUGH EXTENDS NE FROM THE LOW CENTER ACROSS EASTERN PUERTO RICO INTO THE ATLC ALONG 18N65W. THE CONVECTION GENERATED FROM THIS SYSTEM COVERS THE AREA N OF 15N BETWEEN 62W AND 68W. DOPPLER RADAR IMAGERY FROM PUERTO RICO INDICATES SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS IN THIS AREA. MODEL GUIDANCE SUGGEST THE LOW LEVEL CIRCULATION OF GASTON WILL CONTINUE TO WEAKEN OVER THE NEXT 24 HOURS AND DISSIPATE BY 48 HOURS AS IT MOVES WEST ACROSS THE N CARIBBEAN. HOWEVER...THE REMNANT TROUGH WILL CONTINUE TO GENERATE CONVECTION ACROSS THIS REGION DURING THE FORECAST PERIOD. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THE SW BASIN S OF 15N W OF 75W...ASSOCIATED WITH NEARBY CONVERGENCE IN THE VICINITY OF THE MONSOONAL TROUGH/ITCZ. COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER IN THIS REGION OVER THE NEXT 24 HRS. RELATIVELY DRY/STABLE CONDITIONS ARE NOTED ELSEWHERE ACROSS THE CARIBBEAN THIS AFTERNOON. ATLANTIC OCEAN... A BROAD ELONGATED UPPER LEVEL LOW CENTERED BETWEEN EASTERN CUBA AND JAMAICA SUPPORTS A RATHER WEAK SURFACE TROUGH ANALYZED FROM 24N74W TO 20N77W ENHANCING SCATTERED WEAK CONVECTION WITHIN 70 NM EAST OF THE TROUGH AXIS. A LONGWAVE UPPER LEVEL TROUGH IS MOVING OFF THE EASTERN SEABOARD SUPPORTING A SURFACE TROUGH ANALYZED FROM 31N75W TO 27N78W PRODUCING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION TO THE FAR WESTERN ATLC W OF 75W INCLUDING THE FLORIDA STRAITS. THIS AREA OF CONVECTION IS EXPECTED TO LINGER IN THIS REGION OVER THE NEXT 24 HRS. A SURFACE TROUGH EXTENDS FROM THE REMNANT LOW CENTER OF GASTON IN THE NE CARIBBEAN ACROSS PUERTO RICO INTO THE ATLANTIC FROM 17N63W TO 23N66W. SCATTERED WEAK CONVECTION IS WITHIN 200 NM WEST OF THE TROUGH AXIS N OF 20N...EXPECTED TO BECOME LESS IN 24 TO 48 HRS. ANOTHER SURFACE TROUGH IS OVER THE EASTERN ATLC EXTENDING FROM 22N34W TO 15N25W GENERATING SCATTERED MODERATE CONVECTION WITHIN 70 NM ON EITHER SIDE OF THE AXIS N OF 16N. THIS SYSTEM WILL CONTINUE TO MOVE WEST WITH CONVECTION OVER THE NEXT 24 HOURS. ELSEWHERE ACROSS THE DISCUSSION AREA...BROAD MID/UPPER LEVEL SUB-TROPICAL RIDGE DOMINATES THE ATLC AND SUPPORTS THE SURFACE 1024 MB HIGH NEAR 37N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA