000 AXNT20 KNHC 290546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 22W S OF 20N MOVING W NEAR 10 KT. A 1011 MB LOW WAS ADDED ALONG THE WAVE NEAR 13N BASED ON A QUIKSCAT DATA. BROAD WAVE WITH A WELL DEFINED LOW LEVEL CIRCULATION. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE W OF THE LOW/WAVE FROM 13N-16N BETWEEN 23W-28W. TROPICAL WAVE IS ALONG 41W S OF 18W MOVING W NEAR 10 KT WITH A 1011 MB LOW ALONG THE WAVE NEAR 10N. BROAD LOW LEVEL INVERTED-V CURVATURE WITH WELL DEFINED LOW LEVEL CENTER. THIS SYSTEM IS EXPECTED TO BE MOVING INTO A MORE FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT OVER THE NEXT FEW DAYS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 10N-13N BETWEEN 36W-46W. TROPICAL WAVE IS ALONG 67W S OF 20N MOVING W NEAR 15 KT. NARROW INVERTED-V CURVATURE EVEN THOUGH THE CARIBBEAN IS UNDER RATHER DRY STABLE AIR. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 17N-20N BETWEEN 66W-69W. TROPICAL WAVE IS ALONG 85W/86W S OF 23N MOVING W 10 KT. A LOW/MID LEVEL CYCLONIC ROTATION IS TO THE W OF THE WAVE AXIS OVER BELIZE WITH AN UPPER HIGH NEAR THE WAVE AXIS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 16N-23N BETWEEN 82W-89W. TROPICAL WAVE PREVIOUSLY ALONG 95W HAS BEEN DROPPED. A 1008 MB LOW HAS DEVELOPED IN THE E PACIFIC REGION AND IS NEARLY STATIONARY. THE E PACIFIC REGION IS UNDER SW SURFACE FLOW THUS TROPICAL WAVES ARE NOT ABLE TO MAINTAIN THEIR EXISTENCE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 15N15W 10N24W 9N31W 10N40W 8N60W. IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF W AFRICA FROM 15N-19N E OF 18W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 5N-10N BETWEEN 23W-40W. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE EXTENDS INTO THE GULF NEAR TAMPICO MEXICO NNE TO OVER THE MISSISSIPPI VALLEY COVERING THE W GULF W OF 91W GENERATING ENOUGH DIFFLUENCE TO ENHANCE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS OVER THE SW GULF S OF 25N W OF 95W. AN UPPER HIGH IS INLAND OVER S GEORGIA COVERING THE FAR NE GULF. THE UPPER LOW OVER BELIZE EXTENDS AN UPPER TROUGH N OVER THE REMAINDER OF THE GULF GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE CENTRAL GULF FROM 24N-28N BETWEEN 87W-91W...WITHIN 90 NM ALONG THE W COAST OF FLORIDA FROM FLORIDA BAY TO THE BIG BEND AREA...AND IN THE FLORIDA STRAITS W OF ANDROS ISLANDS TO THE MIDDLE FLORIDA KEYS. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE IN THE E BAY OF CAMPECHE S OF 21N E OF 94W. CARIBBEAN SEA... AN UPPER LOW IS OVER BELIZE COVERING THE FAR W OF CARIBBEAN W OF 87W INTO THE YUCATAN CHANNEL. THE UPPER HIGH IS JUST TO THE E NEAR 18N84W EXTENDING A RIDGE AXIS TO JUST ACROSS CENTRAL CUBA ENHANCING CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 85W/86W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE BEING DRAWN TOWARD THE TROPICAL WAVE WITHIN 60 NM OF LINE FROM 10N78W TO THE TIP OF NICARAGUA/HONDURAS. 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. DRY RATHER STABLE AIR COVERS THE E CARIBBEAN E OF 75W. ATLANTIC OCEAN... AN UPPER HIGH OVER S GEORGIA EXTENDS AN UPPER RIDGE E TO NEAR 30N70W AND COVERS THE W ATLC N OF 24N W OF 70W. AN UPPER LOW IS IN THE W/CENTRAL ATLC NEAR 28N63W EXTENDING AN UPPER TROUGH SSW TO OVER HISPANIOLA AND NNE TO JUST BEYOND 32N59W GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 26N-32N BETWEEN 59W-65W. A DEEP LAYERED TROUGH EXTENDS S INTO THE E/CENTRAL ATLC N OF 26N FROM 30W-45W WITH THE ASSOCIATED DISSIPATING COLD FRONT EXTENDING THROUGH 32N37W SW ALONG 29N44W TO NEAR 31N51W WITH ISOLATED SHOWERS/THUNDERSTORMS WITHIN 120 NM OF THE FRONT E OF 45W. A BROAD UPPER HIGH IS ANCHORED IN THE CENTRAL ATLC NEAR 22N54W WITH DRY STABLE AIR COVERING THE ATLC E OF 50W AND COUPLED WITH A WEAK SURFACE RIDGE COVERING THE ATLC ANCHORED WITH A 1020 MB HIGH NEAR 27N54W GIVES THE REMAINDER OF THE ATLC FAIR WEATHER CLOUDS WITH LIGHT TO MODERATE TRADE WINDS. $$ WALLACE