000 AXNT20 KNHC 311029 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 31 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 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 29W/30W S OF 21N DRIFTING W WITH A 1011 MB LOW ALONG THE WAVE NEAR 14.5N. BROAD ELONGATED LOW/MID LEVEL CYCLONIC ROTATION COVERING THE AREA FROM 12N-19N BETWEEN 28W-37W WITH SEVERAL POSSIBLE ILL-DEFINED LOW LEVEL CIRCULATIONS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 13N-17N BETWEEN 30W-35W. TROPICAL WAVE IS ALONG 55W/56W S OF 16W MOVING W 15 KT WITH A 1010 MB LOW ALONG THE WAVE NEAR 11N. BROAD BUT LOW AMPLITUDE LOW/MID LEVEL CYCLONIC ROTATION COVERS THE AREA FROM 9N-14N BETWEEN 53W-59W. THIS WAVE/LOW CONTINUES TO BECOME BETTER ORGANIZED AND COULD BECOME A TROPICAL DEPRESSION LATER TODAY. SCATTERED MODERATE/STRONG CONVECTION IS FROM 9N-13N BETWEEN 52W-59W. TROPICAL WAVE IS ALONG 78W S OF 23N MOVING W NEAR 10 KT. NARROW INVERTED-V CURVATURE REMAINS WEAK IN THE CARIBBEAN AND IS PRODUCING LIMITED SHOWER ACTIVITY DUE TO THE RATHER DRY STABLE AIR. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N15W 14N28W 8N42W 12N52W 11N64W. IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 200 NM ALONG THE COAST OF SW AFRICA S OF 10N ACROSS THE PRIME MERIDIAN AND WITHIN 90/120 NM OF THE ITCZ AXIS FROM 38W-53W. DISCUSSION... GULF OF MEXICO... UPPER TROUGH EXTENDS FROM SE LOUISIANA TO THE COAST OF MEXICO NEAR TAMPICO. BROAD UPPER RIDGE EXTENDS FROM S MEXICO ACROSS THE BAY OF CAMPECHE AND THE REMAINDER OF THE GULF TO OVER GEORGIA TO ALONG THE COAST OF THE CAROLINAS. AT THE SURFACE...THE WEAK 1011 MB LOW PREVIOUSLY ALONG THE COAST OF MEXICO IS NOW A SURFACE TROUGH EXTENDING FROM VERACRUZ MEXICO TO NEAR 23N93W...A FRONTAL BOUNDARY REMAINS INLAND OVER THE SE US FROM E TENNESSEE TO CENTRAL TEXAS...AND A WEAK SURFACE RIDGE EXTENDS FROM THE CENTRAL PLAIN STATES OVER THE W GULF AND NE MEXICO WITH A 1017 MB HIGH CENTERED OVER THE RIO GRANDE NEAR 27N99W. SCATTERED MODERATE/STRONG CONVECTION IS INLAND AND WITHIN 90 NM ALONG THE COAST OF MEXICO S OF 22N W OF 92W. SCATTERED SHOWERS/THUNDERSTORMS COVER THE REMAINDER OF THE AREA S OF 26N W OF 87W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE N AND E GULF COASTS FROM GALVESTON TEXAS TO THE FLORIDA STRAITS. CARIBBEAN SEA... AN UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE W CARIBBEAN W OF 87W. AN UPPER TROUGH EXTENDS FROM OVER HAITI SW TO AN UPPER LOW IN THE SW CARIBBEAN NEAR 13N80W CONTINUING TO OVER PANAMA AND COSTA RICA. AN UPPER RIDGE COVERS THE E CARIBBEAN EXTENDING FROM AN UPPER HIGH OVER VENEZUELA TO THE MONA PASSAGE. ALTHOUGH ITCZ AXIS EXTENDS ACROSS THE N PORTION OF SOUTH AMERICA AND THE SW CARIBBEAN FROM COLOMBIA TO PANAMA/COSTA RICA INTO THE E PACIFIC REGION IT IS ONLY AMBLE TO GENERATE SOME ISOLATED SHOWERS/THUNDERSTORMS S OF 13N W OF 70W DUE TO THE ABUNDANCE OF DRY AIR. SCATTERED CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE N CARIBBEAN N OF 16N FROM 70W-82W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM OF LINE FROM THE WINDWARD ISLANDS NEAR 12N61W NW TO OVER PUERTO RICO NEAR 18N66W. MODERATE/STRONG EASTERLY TRADE WINDS REMAIN ACROSS THE CARIBBEAN. ATLANTIC OCEAN... BROAD UPPER RIDGE COVERS THE W ATLC W OF 77W WITH A NARROW UPPER TROUGH EXTENDING THROUGH 32N72W S ACROSS THE CENTRAL BAHAMA ISLANDS TO THE N COAST OF CUBA NEAR 21N75W. A WEAK 1010 MB LOW IS IN THE W ATLC NEAR 30N74W WITH A SURFACE TROUGH EXTENDING S TO OVER THE N BAHAMA ISLANDS NEAR 24N78W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 25N TO OVER THE GREATER ANTILLES BETWEEN 72W-79W. AN UPPER HIGH IS JUST TO THE E NEAR 27N68W GIVING THE AREA ENOUGH DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION N OF 25N BETWEEN 60W-74W. BROAD UPPER TROUGH EXTENDING FROM 27N44W TO 17N53W AND AN UPPER HIGH CENTERED NEAR 23N29W ARE BOTH RATHER BENIGN FEATURES AND COUPLED WITH THE DRY STABLE AIR THAT COVERS THE ATLC E OF 60W WITH A WEAK SURFACE RIDGE ALSO COVERING THE ATLC E OF 65W GIVES THE REMAINDER OF THE ATLC FAIR WEATHER CLOUDS WITH LIGHT TO MODERATE TRADE WINDS. $$ WALLACE