000 AXNT20 KNHC 260556 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE AUG 26 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...SPECIAL FEATURES... TROPICAL STORM GUSTAV IS CENTERED NEAR 16.8N 71.6W AT 26/0600 UTC OR ABOUT 115 NM SOUTH-SOUTHEAST OF PORT AU PRINCE HAITI MOVING NORTHWEST AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 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. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 15N-18N BETWEEN 70W-75W WITH ISOLATED SHOWERS/THUNDERSTORMS DOTTING THE AREA N OF 13N BETWEEN 70W-76W AND N OF 17N FROM THE VIRGIN ISLANDS TO THE DOMINICAN REPUBLIC. ADDITIONAL STRENGTHENING IS FORECAST AND GUSTAV IS EXPECTED TO BECOME A HURRICANE LATER TODAY BEFORE REACHING THE COAST OF HAITI LATER TODAY. GUSTAV IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 7 INCHES OVER HISPANIOLA...WITH ISOLATED MAXIMUM AMOUNTS OF UP TO 25 INCHES POSSIBLE. THESE INTENSE RAINS MAY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. ...TROPICAL WAVES... A 1008 MB LOW IS OVER THE CAPE VERDE ISLANDS NEAR 15N24W MOVING NW NEAR 10 KT. THIS LOW IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE WITH ANY DEEP CONVECTION TO THE S OF THE ISLANDS. TROPICAL WAVE IS ANALYZED ALONG 34W S OF 19N WITH A 1009 MB LOW ALONG THE WAVE NEAR 12N. IT APPEARS THAT THE TROPICAL WAVE HAS LEFT THE LOW BEHIND AND WILL BE RELOCATED AT 26/0600 UTC ALONG 36W/37W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 10N-13N BETWEEN 33W-37W. TROPICAL WAVE IS IN THE E CARIBBEAN IS ALONG 69W S OF 13N MOVING W NEAR 20 KT. WAVE REMAINS EMBEDDED WITHIN THE DEEP LAYERED MOISTURE BUT IS MOSTLY INLAND OVER SOUTH AMERICA...THUS NO ASSOCIATED SHOWERS OVER THE CARIBBEAN WATERS. TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 84W/85W S OF 21N MOVING W NEAR 20 KT. THIS WAVE IS EMBEDDED WITHIN SOME DRIER AIR...THUS ONLY ISOLATED SHOWERS/THUNDERSTORMS ARE IN THE GULF OF HONDURAS S OF 19N BETWEEN 84W-86W. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 19N15W 10N37W 9N45W 12N62W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 150 NM OF LINE FROM 14N23W TO 7N31W AND WITHIN 90 NM OF LINE FROM 8N31W TO 9N41W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 15N-18N BETWEEN THE COAST OF W AFRICA TO 20W. ...DISCUSSION... GULF OF MEXICO... T.D. FAY REMAINS INLAND OVER CENTRAL MISSISSIPPI BUT CONTINUES TO GENERATE ISOLATED SHOWERS/THUNDERSTORMS IN THE GULF WATERS N OF 25N W OF 86W TO THE COAST OF TEXAS. SMALL UPPER LOW IS CENTERED ALONG THE TEXAS COAST COVERING THE W GULF WITH AN UPPER RIDGE EXTENDING E ACROSS MEXICO ALONG 22N OVER THE SW GULF PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE ISOLATED SHOWERS/ THUNDERSTORMS WITHIN 75 NM ALONG THE COAST OF MEXICO FROM S OF TUXPAN MEXICO TO THE TEXAS BORDER. AN UPPER HIGH REMAINS ANCHORED IN THE FLORIDA STRAITS COVERING THE E GULF. THIS SCENARIO IS KEEPING THE REMAINDER OF THE GULF MOSTLY QUIET AGAIN TONIGHT. CARIBBEAN SEA... THE MAIN CONCERN TONIGHT FOR THE CARIBBEAN IS T.S. GUSTAV...SEE SPECIAL FEATURES ABOVE. THE UPPER OUTFLOW ASSOCIATED WITH GUSTAV IS ELONGATED E/W WITH MAINLY EASTERLY UPPER FLOW OVER THE CARIBBEAN E OF 80W. AN UPPER RIDGE IS ANCHORED IN THE FLORIDA STRAITS GIVING THE NW CARIBBEAN SE UPPER FLOW. THE ITCZ AXIS CROSSES THE EXTREME S CARIBBEAN GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 45 NM ALONG THE COAST OF COLOMBIA THROUGH S NICARAGUA. DEEP LAYERED MOISTURE DOMINATES THE ENTIRE CARIBBEAN. HOWEVER...OTHER THAN THE ACTIVITY NOTED ABOVE AND THAT ASSOCIATED WITH THE TROPICAL WAVE ALONG 84W/85W...THE SKIES REMAIN RATHER CLEAR TONIGHT OVER THE REMAINDER OF THE AREA. ATLANTIC OCEAN... AN UPPER RIDGE COVERS THE FAR W ATLC ANCHORED IN THE FLORIDA STRAITS EXTENDING A RIDGE AXIS N TO BEYOND 32N75W. BROAD UPPER TROUGH IS OVER THE W ATLC ANCHORED N OF THE REGION COVERING THE AREA FROM 59W-75W GENERATING SCATTERED/NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORMS FROM 22N-30N BETWEEN 57W-65W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120/150 NM OF LINE FROM 23N64W OVER THE GREATER ANTILLES NEAR THE E TIP OF THE DOMINICAN REPUBLIC. A SURFACE TROUGH IS ALSO EMBEDDED WITHIN THIS SAME AREA EXTENDING FROM 20N64W TO 29N57W. AN UPPER RIDGE IS ANCHORED IN THE CENTRAL ATLC NEAR 19N58W. A WEAK 1012 MB SURFACE LOW IS BENEATH THIS UPPER RIDGE NEAR 19N53W WITH THE UPPER LEVEL DIFFLUENCE ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 225 NM OF THE SURFACE LOW. A SECOND UPPER TROUGH COVERS THE E ATLC EXTENDING THROUGH 32N33W ALONG 22N36W INTO THE TROPICS TO 12N46W...HOWEVER THIS IS A RATHER BENIGN FEATURE. BROAD SURFACE RIDGE REMAINS OVER THE ATLC N OF 25N E OF 70W ANCHORED BY A SERIES OF HIGHS N OF THE REGION AND A WEAKNESS NEAR THE SURFACE TROUGH. $$ WALLACE