000 AXNT20 KNHC 271054 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED AUG 27 2008 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM GUSTAV IS CENTERED NEAR 18.6N 73.5W AT 27/0900 UTC OR ABOUT 70 NM WEST OF PORT AU PRINCE HAITI AND ABOUT 135 NM SOUTHEAST OF GUANTANAMO CUBA MOVING WEST-NORTHWEST AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND/OR THE PUBLIC ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. A WNW TO W TRACK IS FORECAST DURING THE NEXT DAY OR TWO WITH A GRADUAL INCREASE IN FORWARD SPEED. ON THE FORECAST TRACK GUSTAV SHOULD PASS BETWEEN JAMAICA AND THE SE COAST OF CUBA ON THU. SLOW STRENGTHENING IS FORECAST AND GUSTAV COULD REGAIN HURRICANE STRENGTH ON THU AS IT MOVES FURTHER AWAY FROM HAITI. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER IN THE SE QUADRANT AND WITHIN 75 NM OF 16N FROM 74W-77W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ELSEWHERE FROM 16N-20N BETWEEN 69W-76W. GUSTAV IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 6 TO 12 INCHES OVER HISPANIOLA... EASTERN CUBA...JAMAICA...AND THE CAYMAN ISLANDS...WITH ISOLATED MAXIMUM AMOUNTS OF UP TO 25 INCHES POSSIBLE. THESE RAINS WILL LIKELY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 30W/31W S OF 22N MOVING W 10-15 KT. THIS WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE WITH A BROAD MID LEVEL CYCLONIC TURNING EVIDENT ON SATELLITE IMAGERY. CONVECTION IS WELL REMOVED FROM THE LOW CENTER WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 150 NM OF LINE FROM 9N31W TO 16N4W AND WITHIN 75 NM OF LINE FROM 20N31W TO 15N37W. TROPICAL WAVE IS ALONG 44W/45W S OF 15N MOVING W NEAR 20 KT. LOW AMPLITUDE WAVE IS EMBEDDED WITHIN SOME RATHER DRIER AIR. THUS...NO ASSOCIATED SHOWERS/DEEP CONVECTION. TROPICAL WAVE IN THE S/CENTRAL CARIBBEAN IS ALONG 77W/78W S OF 13N MOVING W 15-20 KT. ALTHOUGH THIS WAVE REMAINS EMBEDDED WITHIN DEEP LAYERED MOISTURE IT IS MOSTLY INLAND OVER THE E PACIFIC REGION AND PRODUCING ONLY ISOLATED SHOWERS IN THE CARIBBEAN WATERS S OF 12N FROM 75W-80W. TROPICAL WAVE IN THE GULF OF MEXICO IS ALONG 93W/94W S OF 19N MOVING W 15-20 KT. WAVE IS MOSTLY OVER S MEXICO AND THE E PACIFIC REGION PRODUCING SCATTERED SHOWERS/THUNDERSTORMS IN THAT AREA. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 17N15W 16N23W 13N31W 9N40W 7N53W 8N60W. ALL THE CONVECTION IN THE AREA IS ASSOCIATED WITH THE TROPICAL WAVE ALONG 30W/31W. ...DISCUSSION... GULF OF MEXICO... THE REMNANT LOW OF FAY IS SLOWLY MOVING NE INTO TENNESSEE WITH A SURFACE TROUGH EXTENDING INTO THE GULF WATERS OVER TALLAHASSEE JUST E OF PANAMA CITY FLORIDA SW TO 28N89W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N BETWEEN APALACHICOLA BAY FLORIDA AND THE LOUISIANA/TEXAS BORDER. WEAK UPPER TROUGH DIGS SW ACROSS THE NW GULF EXTENDING FROM CENTRAL LOUISIANA TO NEAR TAMPICO MEXICO. UPPER HIGH REMAINS ANCHORED IN THE FLORIDA STRAITS NEAR 24N80W COVERING THE REMAINDER OF THE GULF ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. UPPER DIFFLUENCE IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM ALONG THE COAST OF MEXICO S OF MATAMOROS INTO THE BAY OF CAMPECHE NEAR 91W. THE REMAINDER OF THE GULF IS QUIET AGAIN THIS MORNING WITH POSSIBLE ISOLATED SHOWERS S OF A LINE FROM FORT MYERS FLORIDA TO 23N90W. CARIBBEAN SEA... THE MAIN CONCERN FOR THE CARIBBEAN IS T.S. GUSTAV NEAR SW HAITI...SEE SPECIAL FEATURES ABOVE. AN UPPER HIGH CENTERED OVER THE FLORIDA STRAITS COVERS THE NW CARIBBEAN AND IS PROVIDING UPPER LEVEL DIFFLUENCE TO PRODUCE CLUSTERS OF SCATTERED SHOWERS/ THUNDERSTORMS FROM 16N-20N BETWEEN 77W-82W AND IN THE GULF OF HONDURAS S OF 18N W OF 87W TO INLAND OVER THE YUCATAN. THIS UPPER RIDGE IS ALSO CLEARING THE REMAINDER OF THE NW CARIBBEAN CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE BEING DRAWN N INTO THE FLOW ASSOCIATED WITH T.S. GUSTAV OVER THE CENTRAL CARIBBEAN FROM THE COAST OF SOUTH AMERICA TO 16N BETWEEN 68W-74W. AN UPPER RIDGE EXTENDS FORM THE E CARIBBEAN NEAR 15N67W ACROSS THE LESSER ANTILLES NEAR MARTINIQUE CLEARING THE SE CARIBBEAN S OF 15N E OF 66W. ATLANTIC OCEAN... AN UPPER RIDGE ANCHORED IN THE FLORIDA STRAITS NEAR 24N80W COVERS THE W ATLC W OF 72W. BROAD UPPER TROUGH ENCOMPASSES THE REMAINDER OF THE W ATLC FROM 60W-72W WITH AN EMBEDDED UPPER LOW N OF PUERTO RICO NEAR 22N67W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 21N TO OVER THE GREATER ANTILLES BETWEEN 64W-70W INCLUDING THE VIRGIN ISLANDS. A SURFACE TROUGH IS TO THE E OF THE UPPER TROUGH EXTENDING ALONG 28N63W TO 23N66W GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 23N-27N BETWEEN 63W-68W. AN UPPER RIDGE EXTENDS FROM THE E CARIBBEAN NEAR MARTINIQUE TO NEAR 15N52W WITH A WEAK 1011 MB SURFACE LOW NEAR 20N58W AND COUPLED WITH THE UPPER LEVEL DIFFLUENCE IS GENERATING CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 14N-22N BETWEEN 50W-61W. A SECOND BUT BENIGN UPPER LOW COVERS THE E/CENTRAL ATLC CENTERED NEAR 29N44W EXTENDING S TO 22N. AN UPPER RIDGE COVERS THE REMAINDER OF THE E ATLC ANCHORED BETWEEN THE CANARY ISLANDS AND THE WESTERN SAHARA. BROAD SURFACE RIDGE REMAINS OVER THE ATLC N OF 25N E OF 55W ANCHORED BY A 1029 MB HIGH N OF THE AZORES. A WEAK 1016 MB HIGH REMAINS SW OF BERMUDA NEAR 30N71W. $$ WALLACE