000 AXNT20 KNHC 151042 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED AUG 15 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 DEPRESSION FIVE IS CENTERED NEAR 24.6N 91.8W AT 15/0900 UTC OR ABOUT 320 NM ESE OF BROWNSVILLE TEXAS MOVING NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. SYSTEM HAS NOT BECOME MORE ORGANIZED DURING THE NIGHT WITH SATELLITE IMAGERY HINTING AT MULTIPLE LOW LEVEL CENTERS. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER OVER THE N SEMICIRCLE. ALTHOUGH UPPER LEVEL WINDS ARE BECOMING MORE FAVORABLE FOR FURTHER DEVELOPMENT THE LACK OF CURRENT ORGANIZATION AND THE LIMITED TIME THE SYSTEM WILL REMAIN OVER WATER THIS SYSTEM IS NOT EXPECTED TO STRENGTHEN TOO MUCH. TROPICAL STORM DEAN IS CENTERED NEAR 12.2N 44.2W AT 15/0900 UTC MOVING W AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. THE ASSOCIATED DEEP CONVECTION REMAINS SLIGHTLY DISPLACED TO THE W OF THE CENTER DUE TO EASTERLY SHEAR BANDING IS BEGINNING BUT IS CURRENTLY NOT WELL ORGANIZED. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10.5N-13N BETWEEN 42.5W-45W. THE SYSTEM CONTINUES TO MOVE RATHER BRISKLY ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYER RIDGE. AS DEAN CONTINUES TO APPROACH THE LESSER ANTILLES IT WILL BEGIN TO ENCOUNTER WARMER WATER AND LESS WIND SHEAR AND WILL LIKELY BECOME A HURRICANE AS IT NEARS THE ISLANDS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 28W/29W S OF 20N MOVING W 15-20 KT WITH A 1011 MB LOW ALONG THE WAVE NEAR 14N. THE SURFACE LOW CONTINUES TO WEAKEN AS THE BROAD LOW/MID LEVEL ROTATION REMAINS. SCATTERED THUNDERSTORMS ARE FROM 13N-16N BETWEEN 28W-32W WITH CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 6N-11N BETWEEN 28W-32W. TROPICAL WAVE IS ALONG 56W/57W S OF 19N MOVING W 15-20 KT. WEAK BUT WELL DEFINED LOW LEVEL INVERTED-V CURVATURE IS OBSERVED. NO ASSOCIATED DEEP CONVECTION WITH SOME WIDELY ISOLATED SHOWERS ARE FROM 11N-15N BETWEEN 56W-59W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 16N16W 14N25W 11N36W 13N40W 8N51W 10N62W. SEE SPECIAL FEATURES ABOVE. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 9N-12N BETWEEN 46W-55W AND ALONG THE COAST OF AFRICA FROM 10N-12N E OF 17W. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS TONIGHT IS NOW NEWLY FORMED TROPICAL DEPRESSION FIVE IN THE CENTRAL GULF...SEE SPECIAL FEATURES ABOVE. DENSE CLOUDINESS WITH ISOLATED SHOWERS/THUNDERSTORMS COVERS THE NW GULF N OF 25N W OF 92W TO THE TEXAS COAST. AN UPPER HIGH HAS DEVELOPED NEAR T.D. FIVE WITH AN UPPER RIDGE EXTENDING SE TO THE YUCATAN CHANNEL AND NW TO THE COAST NEAR THE LOUISIANA/TEXAS BORDER. AN UPPER TROUGH IS IN THE FAR W ATLC TO OVER FLORIDA AND IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS ALONG THE W FLORIDA COAST FROM FLORIDA BAY TO TAMPA. ISOLATED SHOWERS DOT THE SE GULF AND THE BAY OF CAMPECHE. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE NW CARIBBEAN N OF 15N W OF 75W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 20N W OF 76W. AN UPPER TROUGH EXTENDS INTO THE E CARIBBEAN ACROSS PUERTO RICO FROM AN UPPER LOW N OF PUERTO RICO TO NEAR 13N71W. THE ITCZ AXIS CROSSES THE N PORTION OF SOUTH AMERICA...PANAMA...AND COSTA RICA INTO THE E PACIFIC REGION GENERATING SOME SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN S OF 14N W OF 74W TO INLAND OVER COLOMBIA AND CENTRAL AMERICA. FOR THE MOST PART...DRY STABLE AIR DOMINATES THE REMAINDER OF THE CARIBBEAN WITH SOME WIDELY ISOLATED LOW LEVEL TRADE WIND INDUCED SHOWERS MAINLY E OF 70W. ATLANTIC OCEAN... DEEP LAYERED TROUGH DIPS S INTO THE W ATLC N OF 23N W OF 69W TO OVER FLORIDA WITH A WEAK REMNANT SURFACE TROUGH EXTENDING THROUGH 32N62W SW TO THE BAHAMAS NEAR 25N76W. THIS TROUGH CONTINUES TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120/150 NM OF LINE FROM 22N71W NE TO 29N67W. THE REMAINDER OF THE ATLC IS DOMINATED BY RATHER BENIGN UPPER FEATURES WITH THE EXCEPTION OF TROPICAL STORM DEAN. DRY STABLE AIR AND A BROAD SURFACE RIDGE ANCHORED BY A 1026 MB HIGH W OF THE AZORES WELL N OF THE REGION GIVING THE ATLC E OF 60W FAIR WEATHER CLOUDS AND LITTLE CHANCE OF SHOWER ACTIVITY. $$ WALLACE