000 AXNT20 KNHC 150503 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0415 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION FIVE WAS UPGRADED AT 15/0300 UTC AND IS CENTERED NEAR 23.9N 91.1W AT 15/0300 UTC OR ABOUT 370 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. THE AIR FORCE RECONNAISSANCE AIRCRAFT DID FIND A SMALL LOW LEVEL CENTER...THUS THE UPGRADE TO TROPICAL DEPRESSION. HOWEVER...THE ASSOCIATED DEEP CONVECTION IS SLIGHTLY DISPLACED TO THE NE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 24N-26N BETWEEN 89W-92W. ALTHOUGH RAPID DEVELOPMENT IS NOT EXPECTED AT THIS TIME...A MORE FAVORABLE ENVIRONMENT IS EXPECTED OVER THE NEXT DAY OR TWO. TROPICAL STORM DEAN IS CENTERED NEAR 12.0N 42.3W AT 15/0300 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. ALTHOUGH THE ASSOCIATED DEEP CONVECTION REMAINS DISPLACED TO THE W OF THE CENTER DUE TO EASTERLY SHEAR THIS IS BEGINNING TO WEAKEN. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 10N-13N BETWEEN 41W-44W. THE SYSTEM CONTINUES TO MOVE RATHER BRISKLY BUT HAS SLOWED A LITTLE OVER THE PAST 24 HOURS CONTINUING ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYER RIDGE. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 27W/28W S OF 20N MOVING W 15-20 KT WITH A 1012 MB LOW SW OF THE CAPE VERDE ISLANDS NEAR 14N27W. THE SURFACE LOW IS BEGINNING TO WEAKEN WHILE THE BROAD LOW/MID LEVEL ROTATION REMAINS. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE S OF THE LOW AND ITCZ AXIS FROM 7N-13N BETWEEN 24W-32W. TROPICAL WAVE IS ALONG 55W/56W S OF 18N MOVING W 15-20 KT. WEAK BUT WELL DEFINED LOW LEVEL INVERTED-V CURVATURE IS OBSERVED. NO ASSOCIATED SHOWER ACTIVITY/CONVECTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N15W 14N24W 12N33W 10N49W 9N62W. SEE SPECIAL FEATURES ABOVE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90/120 NM OF THE ITCZ AXIS FROM 45W-47W AND MOVING OFF THE COAST OF AFRICA FROM 7N-11N E OF 16W. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS TONIGHT IS NOW NEWLY FORMED TROPICAL DEPRESSION FIVE IN THE S/CENTRAL GULF...SEE SPECIAL FEATURES ABOVE. DENSE CLOUDINESS WITH ISOLATED SHOWERS/THUNDERSTORMS COVERS THE N GULF N OF 25N FROM 86W-95W. AN UPPER RIDGE EXTENDS FROM THE YUCATAN PENINSULA ACROSS THE CENTRAL GULF AND THE LOUISIANA COAST TO A LARGE UPPER HIGH OVER OKLAHOMA ENHANCING CONVECTION ASSOCIATED WITH THE T.D. FIVE. AN UPPER TROUGH IN THE FAR W ATLC TO OVER FLORIDA IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS ALONG THE W FLORIDA COAST FROM TAMPA TO THE BIG BEND AREA WITH HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS OVER THE SE GULF S OF 26N E OF 87W WHILE THE E MEXICO AND SE TEXAS COAST REMAIN CLEAR TONIGHT. THIS WILL CHANGE AS T.D. FIVE CONTINUES ON ITS NW TRACK. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE W CARIBBEAN W OF 77W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAINLY N OF 19N W OF 80W AND A SMALL CLUSTER OVER THE S PENINSULA OF HAITI. AN UPPER LOW N OF PUERTO RICO EXTENDS AN UPPER TROUGH INTO THE E CARIBBEAN SW TO NEAR 14N73W. THE ITCZ AXIS CROSSES THE N PORTION OF SOUTH AMERICA...PANAMA...AND COSTA RICA INTO THE E PACIFIC REGION GENERATING SOME ISOLATED SHOWERS/THUNDERSTORMS MOSTLY WITHIN 90 NM ALONG THE COLOMBIAN COAST. 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 65W. ATLANTIC OCEAN... DEEP LAYERED TROUGH DIPS S INTO THE W ATLC N OF 23N W OF 70W TO OVER FLORIDA WITH A WEAKEN REMNANT SURFACE TROUGH EXTENDING THROUGH 32N61W SW TO THE BAHAMAS NEAR 26N76W. THIS TROUGH CONTINUES TO GENERATE ISOLATED SHOWERS WITH POSSIBLE EMBEDDED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM 27N71W NE TO BEYOND 32N63W. AN UPPER RIDGE EXTENDS FROM THE GULF OF MEXICO THROUGH THE FLORIDA STRAITS INTO THE SW ATLC TO OVER THE TURKS AND CAICOS ENHANCING SCATTERED SHOWERS/THUNDERSTORMS S OF THE BAHAMA ISLANDS TO OVER CUBA W OF 76W INTO THE SE GULF OF MEXICO. THE REMAINDER OF THE ATLC IS DOMINATED BY RATHER BENIGN UPPER FEATURES WITH THE EXCEPTION OF TROPICAL STORM DEAN. MODERATELY DRY STABLE AIR AND A BROAD SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NEAR 33N37W GIVING THE ATLC E OF 60W FAIR WEATHER CLOUDS AND LITTLE CHANCE OF SHOWER ACTIVITY. $$ WALLACE