000 AXNT20 KNHC 051800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN SEP 05 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 FEATURES... A 1009 MB LOW...REMNANT OF GASTON...IS ABOUT 600 NM E OF THE LESSER ANTILLES NEAR 17N51W MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES A LOW LEVEL SWIRL WITH SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION TO THE W FROM 15N-19N BETWEEN 50W-54W. ALTHOUGH ACTIVITY IS CURRENTLY LIMITED...ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT OF THIS SYSTEM AND A TROPICAL DEPRESSION COULD RE-FORM DURING THE NEXT DAY OR TWO. THERE IS A HIGH CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS. A BROAD AREA OF LOW PRESSURE COVERS THE SW GULF WHERE A SURFACE TROUGH IS ANALYZED FROM A 1005 MB LOW 35 NM NE OFF THE COAST OF THE CITY OF VERACRUZ NEAR 19.6N 95.4W. THE SURFACE TROUGH EXTENDS NNE ALONG 23N95W TO 26N93W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE AREA S OF 27N W OF 91W TO INLAND OVER MEXICO. OFFICIAL DATA FROM SEVERAL WEATHER STATIONS IN THE VICINITY OF THE CITY OF VERACRUZ HAVE REGISTERED BETWEEN 1 AND 2 INCHES OF RAIN IN THE PAST 24 HRS. SHORT RANGE COMPUTER MODELS SUGGEST THIS SYSTEM WILL CONTINUE TO MOVE NNW OVER THE NEXT COUPLE OF DAYS WITH SCATTERED MODERATE TO STRONG CONVECTION...BEGINNING TO AFFECT THE TEXAS COAST BY TUESDAY MORNING. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR ADDITIONAL DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM DURING THE NEXT DAY OR SO BEFORE THE SYSTEM MOVES INLAND. THERE IS A HIGH CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS ...TROPICAL WAVES... TROPICAL WAVE REMAINS INLAND OVER WEST AFRICA ALONG 10W MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES CYCLONIC FLOW NEAR THE WAVE AXIS CONCENTRATED NEAR A 1009 MB LOW ALONG AND THE AXIS NEAR 9N. THIS SYSTEM IS EXPECTED TO ENTER THE ATLC OVER THE NEXT 24 HRS. ...ITCZ... A MONSOONAL TROUGH EXTENDS FROM THE COASTAL WATERS OF W AFRICA NEAR 19N20W ALONG 10N23W TO 6N35W...WHERE THE ITCZ AXIS BEGINS AND CONTINUES WESTWARD ALONG 10N45W TO 12N60W. SCATTERED MODERATE TO STRONG CONVECTION IS E OF THE TROUGH FROM 6N TO 14N BETWEEN THE COAST OF WEST AFRICA AND 22W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 4N TO 8N BETWEEN 30W-43W. ...DISCUSSION... GULF OF MEXICO... THE PRIMARY FOCUS THIS AFTERNOON FOR THE GULF OF MEXICO IS THE SURFACE TROUGH/LOW IN THE SPECIAL FEATURES ABOVE. A LONGWAVE UPPER LEVEL TROUGH COVERING MOST OF THE S AND SE CONUS ENTERS THE N GULF NOTED BY STRONG SUBSIDENCE ON WATER VAPOR IMAGERY. THIS UPPER LEVEL FEATURE SUPPORTS A RATHER WEAK STATIONARY FRONT THAT EXTENDS FROM THE W ATLC ACROSS THE NORTHERN FLORIDA PENINSULA INTO THE NE GULF NEAR 29N83W CONTINUING WESTWARD TO 29N92W. A SURFACE TROUGH IS ANALYZED WITHIN 30 N MI S OF THE STATIONARY FRONT BETWEEN 83W AND 91W. THIS SCENARIO IS ENHANCING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION N OF 26N E OF 92W. CARIBBEAN SEA... BROAD ELONGATED UPPER LEVEL LOW CENTERED N OF PUERTO RICO SUPPORTS A SURFACE TROUGH ANALYZED ALONG 24N64W 20N65W 16N64W ENHANCING SCATTERED WEAK TO MODERATE CONVECTION TO THE EASTERN CARIBBEAN N OF 12N E OF 70W. A SURFACE TROUGH IS TO THE SW OF THE UPPER TROUGH EXTENDING FROM NORTHERN COLOMBIA NEAR 10N74W TO THE N COAST OF NICARAGUA NEAR 14N83W GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 100 N MI ON EITHER SIDE OF THE TROUGH. COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER IN THE SW CARIBBEAN OVER THE NEXT 24 HRS. RELATIVELY DRY/STABLE CONDITIONS IS NOTED ELSEWHERE ACROSS THE CARIBBEAN THIS AFTERNOON. ATLANTIC OCEAN... BROAD ELONGATED UPPER LEVEL LOW CENTERED N OF PUERTO RICO NEAR 20N66W SUPPORTS A SURFACE TROUGH ANALYZED ALONG 24N64W 20N65W 16N64W ENHANCING SCATTERED WEAK TO MODERATE CONVECTION S OF 25N BETWEEN 64W AND 72W. UPPER LEVEL JET STREAK/TROUGH MOVING NE OFF THE EASTERN SEABOARD IS ENHANCING SCATTERED MODERATE CONVECTION N OF 27N BETWEEN 68W AND 75W. ELSEWHERE ACROSS THE ACROSS THE DISCUSSION AREA...BROAD MID/UPPER LEVEL SUB-TROPICAL RIDGE DOMINATES THE ATLC AND SUPPORTS THE SURFACE 1024 MB HIGH NEAR 36N45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA