000 AXNT20 KNHC 280540 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 28 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 18.5N 75.7W AT 28/0600 UTC OR ABOUT 70 NM EAST-NORTHEAST OF KINGSTON JAMAICA AND ABOUT 91 NM SOUTH-SOUTHWEST OF GUANTANAMO CUBA MOVING WEST-SOUTHWEST AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 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. GUSTAV IS EXPECTED TO TURN TO THE WEST LATER TODAY AND TO THE WEST-NORTHWEST ON FRI PASSING VERY CLOSE TO JAMAICA LATER TODAY. SLOW RESTRENGTHENING IS FORECAST OVER THE NEXT 48 HOURS AND GUSTAV COULD REGAIN HURRICANE STRENGTH BY FRI. SCATTERED MODERATE/STRONG CONVECTION HAS REGENERATED S OF THE CENTER FROM 17N-19N BETWEEN 74W-75W INCLUDING THE SW TIP OF HAITI AND THE E TIP OF JAMAICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60-75 NM OF LINE FROM 17N72W TO 16N81W. GUSTAV IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 6 TO 12 INCHES OVER HAITI...E 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. A 1008 MB SURFACE LOW IS CENTERED ENE OF THE LEEWARD ISLANDS NEAR 19N58W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME MORE CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM TONIGHT OR THU AS IT DRIFTS NORTHWESTWARD. SCATTERED MODERATE/STRONG CONVECTION IS FROM 17N-21N BETWEEN 55W-59W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 35W/36W S OF 21N WITH A 1009 MB LOW ALONG THE WAVE NEAR 16N MOVING W 15-20 KT. BROAD AREA OF DEEP LAYERED MOISTURE EVIDENT ON MIMIC-TPW ANIMATION AND A BROAD INVERTED-V CURVATURE OBSERVED ON SATELLITE IMAGERY. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE N OF THE LOW CENTER FROM 18N-21N BETWEEN 33W-39W. TROPICAL WAVE IS ALONG 50W S OF 15N MOVING W NEAR 20 KT. LOW AMPLITUDE AND REMAINS EMBEDDED WITHIN SOME RATHER DRY AIR...THUS NO ASSOCIATED SHOWERS/DEEP CONVECTION. THIS WAVE IS MOVING INTO THE AREA OF THE 1008 MB LOW IN THE SPECIAL FEATURES AND DOES NOT APPEAR AS WELL DEFINED AS 24 HOURS AGO. TROPICAL WAVE IN THE SW CARIBBEAN ALONG 83W WAS PREVIOUSLY ASSOCIATED WITH WHAT IS NOW T.S. GUSTAV AND SHORTENED TO S OF 13N. BASED ON SCATTEROMETER SATELLITE WIND DATA THERE IS SW ANTICYCLONIC FLOW ACROSS THE WAVE INDICATING THE WAVE WAS ACTUALLY ABSORBED INTO GUSTAV AND WILL BE DROPPED ON THE 0600 UTC ANALYSIS. TROPICAL WAVE THAT WAS ALONG 97W IS NO LONGER IN THE ATLC BASIN. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 14N15W 17N27W 10N43W 8N54W 7N60W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60 NM OF LINE FROM 9N18W TO 14N19W. SCATTERED MODERATE CONVECTION IS E OF LINE FROM 6N12W TO 10N17W TO THE COAST OF W AFRICA AND WITHIN 60 NM OF THE ITCZ AXIS BETWEEN 27W-30W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS OVER THE E US ENTERING THE NW GULF NEAR NEW ORLEANS SW TO OFF THE MEXICAN COAST NEAR 23N96W WITH AN UPPER HIGH REMAINING ANCHORED IN THE FLORIDA STRAITS NEAR 24N80W COVERING THE E GULF ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. A WEAK UPPER RIDGE AXIS EXTENDS FROM S MEXICO NEAR THE ISTHMUS OF TEHUANTEPEC NE TO OVER THE N YUCATAN PENINSULA E OF MERIDA PROVIDING UPPER DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE BAY OF CAMPECHE WITHIN 45 NM ALONG THE COAST OF THE YUCATAN AND S MEXICO BETWEEN 90W-96W WITH CLUSTERS OF SIMILAR ACTIVITY S OF 23N W OF 94W. AT THE SURFACE...A WEAK 1013 MB HIGH IS CENTERED NEAR 28N92W AND IS KEEPING THE REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES TONIGHT. CARIBBEAN SEA... THE MAIN CONCERN AGAIN TONIGHT FOR THE CARIBBEAN IS T.S. GUSTAV BETWEEN HAITI...CUBA...AND JAMAICA...SEE SPECIAL FEATURES ABOVE. AN UPPER HIGH CENTERED OVER THE FLORIDA STRAITS COVERS THE NW CARIBBEAN N OF 18N BETWEEN 77W-85W WITH THE UPPER RIDGE OVER THE YUCATAN COVERING THE REMAINDER OF THE NW CARIBBEAN INTO THE GULF OF HONDURAS. THE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THESE UPPER RIDGES ARE ABLE TO PRODUCE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OFF THE S CUBA FROM 19N-21N BETWEEN 79W-81W AND WITHIN 60 NM ALONG THE COAST OF THE GULF OF HONDURAS S OF 17N W OF 86W LEAVING THE FAR NW CARIBBEAN RATHER CLEAR TONIGHT. AN UPPER LEVEL RIDGE IS ACROSS THE E CARIBBEAN ALONG 15N BETWEEN 70W TO OVER THE LESSER ANTILLES PROVIDING UPPER DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS E OF 68W FROM THE MONA PASSAGE AND PUERTO RICO TO OVER THE LESSER ANTILLES N OF SAINT VINCENT AND BARBADOS. ATLANTIC OCEAN... AN UPPER RIDGE ANCHORED IN THE FLORIDA STRAITS NEAR 24N80W COVERS THE W ATLC W OF 72W. A DEEP LAYERED TROUGH IS OVER THE NW ATLC DIPPING S TO 30N WITH THE ASSOCIATED FRONTAL BOUNDARY MAINLY N OF THE REGION DIPPING S TO BERMUDA. THE UPPER LOW N OF PUERTO RICO HAS BECOME CUT-OFF NEAR 22N65W GENERATING ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 25N TO OVER THE E GREATER ANTILLES BETWEEN 60W-70W INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS. AN UPPER RIDGE IS DEVELOPING OVER THE 1008 MB SURFACE LOW IN THE SPECIAL FEATURES PROVIDING UPPER DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 12N-21N BETWEEN 52W-62W. A SECOND BENIGN UPPER LOW IS WEAKENING BUT STILL COVERS THE CENTRAL ATLC CENTERED NEAR 31N45W EXTENDING S TO 25N. AN UPPER RIDGE COVERS THE E ATLC E OF 39W ANCHORED ON AN UPPER HIGH BETWEEN THE CAPE VERDE ISLANDS AND THE CANARY ISLANDS NEAR 22N22W. BROAD SURFACE RIDGE REMAINS OVER THE ATLC N OF 25N E OF 50W ANCHORED BY A 1029 MB HIGH N OF THE AZORES. $$ WALLACE