000 AXNT20 KNHC 291042 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED AUG 28 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 23W/24W S OF 20N MOVING W NEAR 10 KT WITH A 1010 MB LOW ALONG THE WAVE NEAR 13N. BROAD INVERTED-V CURVATURE WITH A SMALL LOW LEVEL CIRCULATION. SCATTERED SHOWERS/ THUNDERSTORMS ARE FROM 12N-16N BETWEEN 23W-28W. TROPICAL WAVE IS ALONG 42W S OF 17W MOVING W NEAR 10 KT WITH A 1011 MB LOW ALONG THE WAVE NEAR 10N. BROAD LOW LEVEL INVERTED-V CURVATURE WITH AN EMBEDDED LOW LEVEL CENTER. THIS SYSTEM IS EXPECTED TO BE MOVING INTO A MORE FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT OVER THE NEXT FEW DAYS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-13N BETWEEN 41W-47W. TROPICAL WAVE IS ALONG 68W/69W S OF 25N MOVING W NEAR 15 KT. WAVE HAS GAINED IN AMPLITUDE N OF THE GREATER ANTILLES. HOWEVER IT REMAINS NARROW INVERTED-V CURVATURE AND IS NOT PRODUCING ANY SHOWER ACTIVITY IN THE CARIBBEAN DUE TO THE RATHER DRY STABLE AIR. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM THE TIP OF HISPANIOLA NEAR 19N68W TO 24N66W. TROPICAL WAVE IS ALONG 87W S OF 23N MOVING W 10 KT. AN UPPER HIGH IS JUST E OF THE WAVE AXIS ENHANCING CONVECTION. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 13N-23N BETWEEN 82W-89W INCLUDING PORTIONS OF CENTRAL AMERICA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 15N15W 8N31W 10N46W 7N61W. IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF W AFRICA FROM 15N-18N BETWEEN 17W-21W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 7N-10N BETWEEN 24W-33W. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE EXTENDS ALONG THE COAST OF NE MEXICO AND TEXAS TO OVER THE MISSISSIPPI VALLEY COVERING THE W GULF W OF 93W GENERATING ENOUGH DIFFLUENCE TO ENHANCE SCATTERED SHOWERS/ THUNDERSTORMS OVER THE NW GULF W OF A LINE FROM TAMPICO MEXICO TO W LOUISIANA. AN UPPER HIGH REMAINS INLAND OVER SW GEORGIA COVERING THE FAR NE GULF. THE UPPER LOW OVER THE YUCATAN PENINSULA EXTENDS AN UPPER TROUGH N OVER THE REMAINDER OF THE GULF WITH THE EXCEPTION OF THE STRAITS OF FLORIDA WHERE THERE IS AN UPPER RIDGE EXTENDING FROM THE CARIBBEAN. THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE BAY OF CAMPECHE S OF 21N BETWEEN 92W-97W. THE REMAINDER OF THE GULF IS CLEAR THIS MORNING. CARIBBEAN SEA... AN UPPER HIGH IS S OF THE CAYMAN ISLANDS NEAR 16N82W EXTENDING A RIDGE AXIS ACROSS CUBA TO OVER THE STRAITS OF FLORIDA ENHANCING CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 87W. EASTERLY UPPER FLOW COVERS MOST OF THE REMAINDER OF THE CARIBBEAN WITH THE EXCEPTION OF THE GREATER ANTILLES TO OVER THE VIRGIN ISLANDS WHERE WESTERLY UPPER FLOW DOMINATES IN RESPONSE TO AN UPPER LOW OVER THE W/CENTRAL ATLC GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N FROM 77W-85W. THE ITCZ AXIS EXTENDS FROM OVER COLOMBIA ACROSS PANAMA AND COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED MODERATE/STRONG CONVECTION S OF 11N E OF 81W. DRY RATHER STABLE AIR COVERS THE REMAINDER OF THE CARIBBEAN E OF 75W. ATLANTIC OCEAN... AN UPPER HIGH OVER SW GEORGIA EXTENDS AN UPPER RIDGE ESE TO NEAR 29N70W AND COVERS THE W ATLC N OF 26N W OF 70W. AN UPPER LOW IS IN THE W/CENTRAL ATLC NEAR 28N63W EXTENDING AN UPPER TROUGH SSW TO OVER HISPANIOLA/E CUBA AND NNE TO JUST BEYOND 32N60W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 27N BETWEEN 60W-70W. A DEEP LAYERED TROUGH EXTENDS S INTO THE E/CENTRAL ATLC N OF 23N FROM 30W-50W WITH AN EMBEDDED UPPER LOW NEAR 29N40W AND AN ASSOCIATED SURFACE TROUGH EXTENDING THROUGH 32N35W SW ALONG 29N40W THEN W TO 29N48W WITH ISOLATED SHOWERS/THUNDERSTORMS WITHIN 90/120 NM OF THE TROUGH. A BROAD UPPER HIGH IS ANCHORED IN THE CENTRAL ATLC NEAR 22N53W WITH DRY STABLE AIR COVERING THE ATLC E OF 60W AND COUPLED WITH A WEAK SURFACE RIDGE COVERING THE ATLC ANCHORED WITH A 1021 MB HIGH NEAR 34N58W GIVING THE REMAINDER OF THE ATLC FAIR WEATHER CLOUDS WITH LIGHT TO MODERATE TRADE WINDS. $$ WALLACE