000 AXNT20 KNHC 232357 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU AUG 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... LOW AMPLITUDE TROPICAL WAVE IS OVER THE OPEN ATLANTIC ALONG 44W S OF 14N IS MOVING W 10-15 KT. THE WAVE IS MARKED BY LOW LEVEL CYCLONIC TURNING MAINLY ALONG THE ITCZ. THIS TURNING MAY BE MORE ASSOCIATED WITH THE ITCZ. HOWEVER...THERE IS A SLIGHTLY HIGHER AMPLITUDE INVERTED V PATTERN NOTED FURTHER NW FROM 17N-23N BETWEEN 45W-53W...HOWEVER THE EVOLUTION OF THIS FEATURE OVER THE LAST FEW DAYS IS A LITTLE UNCLEAR AND COULD BE MORE ASSOCIATED WITH LIFT AHEAD OF THE UPPER LOW NEAR 21N56W. IN GENERAL NEITHER AREA IS WELL ORGANIZED AND DEEP CONVECTION IS ABSENT. TROPICAL WAVE ALONG 67W/68W HAS FRACTURED WITH THE MAIN WAVE S OF 17N MOVING W NEAR 20 KT IN MODERATE ELY FLOW OVER THE CARIBBEAN...WHILE THE NORTHERN PORTION OF THE WAVE HAS SEPARATED INTO A WEAK SFC TROUGH JUST NORTHEAST OF PUERTO RICO...FROM 19N TO 23N ALONG 65W. SCATTERED WEAKENING SHOWERS WITH THIS SRN PORTION HAVE BEEN RACING W THROUGH THE ABC ISLANDS AND NRN VENEZUELA OVER THE LAST FEW HOURS. ADDITIONAL SHOWERS AND TSTMS ARE OCCURRING OVER THE COASTAL WATERS OF PUERTO RICO AND THE VIRGIN ISLANDS. TROPICAL WAVE IS ALONG 81/82W S OF 22N MOVING W 15-20 KT. THE WAVE HAS BECOME DETACHED FROM A 1014 MB SFC LOW NEAR GRAND BAHAMA ISLAND. THIS WAVE APPEARS TO BE HIGHLY AMPLIFIED WITH LOW CLOUD MOTIONS E OF THE WAVE AXIS INDICATING SE FLOW INTO THE WAVE AND AN INCREASING COVERAGE OF SCATTERED SHOWERS AND TSTMS JUST W OF JAMAICA AND EXTENDING NWD OVER ERN CUBA. ITCZ... ITCZ AXIS IS CENTERED ALONG 12N20W 11N35W 10N43W 11N55W 9N61W. SCATTERED BUT WEAKENING MODERATE CONVECTION WAS INDICATED WITHIN 120 NM OF THE AXIS W OF 52W..AND WITHIN 45-60 NM OF A LINE FROM 7N34W TO 7N39W...AND JUST OFFSHORE THE AFRICAN COAST FROM 13N-16N E OF 20W. THE EASTERN MOST CONVECTION IS ASSOCIATED WITH A TROPICAL WAVE THAT RECENTLY MOVED OFF THE COAST AS PER DAKAR RAOB DATA. DISCUSSION... GULF OF MEXICO... RESIDUAL LONG PERIOD SWELLS OF 12 SEC FROM FORMER HURRICANE DEAN CONTINUE TO REGISTER AT MANY OF THE BUOYS OVER THE E-CENTRAL GULF AND IN THE NEAR SHORE WATERS AS WELL. THIS WILL ALSO CONTINUE TO SLOWLY SUBSIDE THROUGH THE END OF THE WEEK. WIDELY SCATTERED SHOWERS AND TSTMS DOT THE CENTRAL GULF MAINLY S OF 29N BETWEEN 87W AND 92W...IN A REGION OF DIFFLUENT FLOW ALOFT BETWEEN AN INVERTED UPPER TROUGH EXTENDING THROUGH THE REGION AND AN UPPER HIGH OVER GEORGIA. EXCEPT FOR RESIDUAL MOISTURE NOTED IN THE BAY OF CAMPECHE...DRY/STABLE MID TO UPPER AIR IS OVER THE WRN GULF E OF 90W WITH E TO NE UPPER FLOW. A WEAK TROPICAL WAVE WILL MOVE INTO THE SE GULF OF MEXICO EARLY FRI...CROSS THE MIDDLE GULF SAT...AND REACH THE FAR WESTERN GULF SUN. MEANWHILE...WEAK SFC RIDGING WILL PERSIST ALONG 30N THROUGH THE WEEKEND. CARIBBEAN SEA... A PAIR OF TROPICAL WAVES ARE MOVING THROUGH THE BASIN AND ARE RESPONSIBLE FOR MOST OF THE WEATHER ACROSS THE BASIN...SEE ABOVE FOR MORE DETAILS. THE SHOWERS/TSTMS JUST S OF CUBA NOTED WITH THE WAVE NEAR 81W/82W ARE ALSO BEING SUPPORTED BY DIFFLUENCE ALOFT BETWEEN THE INVERTED TROUGHING EXTENDING UP THE NW CARIB AND RIDGING BUILDING INTO THE CENTRAL CARIB FROM THE ATLC. OTHERWISE TRADES ARE MODERATE AND GENERALLY EXPECTED TO PERSIST THROUGH FRI. ATLANTIC OCEAN... THE MAIN FEATURE IN THE WRN ATLC IS THE SLOW MOVING...WEAK 1015 MB SFC LOW NEAR GRAND BAHAMA ISLAND. THIS FEATURE HAS BEEN GENERATING ISOLATED TSTMS WITHIN 180 NM IN THE NW QUADRANT TO THE CENTRAL FLORIDA COAST. MUCH OF THE REMAINDER OF THE SFC PATTERN IS DOMINATED BY A WEAK 1020 MB HIGH NEAR 27N61W. A SMALL LOW LEVEL CYCLONIC SWIRL OR 'SCREAMING EAGLE' WAS NOTED ROTATING AROUND THIS RIDGING NEAR 22N56W. THE SFC HIGH WILL SLIDE S THROUGH FRI IN ADVANCE OF THE FRONTAL SYSTEM JUST N OF THE AREA. THE TRADES ARE MOSTLY LIGHT ACROSS THE CENTRAL AND ERN ATLC DUE TO THE WEAKNESS OF THE SFC RIDGE. FAIR/STABLE WEATHER IS WIDESPREAD N OF 13N E OF 65W...ALTHOUGH SCATTERED SHOWERS AND TSTMS WITH THE APPROACHING FRONT ARE NOW N OF 30N BETWEEN 47W-54W. BENIGN UPPER LOWS NOTED NEAR 21N55W AND 32N34W...WITH TYPICAL UPPER RIDGING OVER THE REMAINDER OF THE E ATLC. $$ COBB