000 AXNT20 KNHC 071026 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI SEP 07 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. ...SPECIAL FEATURES... A 1012 MB LOW LOCATED ABOUT 360 NM SW OF BERMUDA NEAR 28.5N70W WITH A SURFACE TROUGH EXTENDING SSW FROM THE LOW TO NEAR 24N72W. THE LOW-LEVEL CENTER REMAINS COMPLETELY EXPOSED BUT IS STARTING TO DRIFT NORTHWARDS. THERE ARE SCATTERED SHOWERS/THUNDERSTORMS N AND E OF THE LOW ASSOCIATED WITH A WEAKENING FRONTAL BOUNDARY ALONG 32. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 27N FROM 70W-77W WITH SHOWERS/THUNDERSTORMS BETWEEN THE BAHAMAS AND CUBA W OF 76W THROUGH THE FLORIDA STRAITS INTO THE GULF OF MEXICO. THE SYSTEM CONTINUES TO INTERACT WITH AN UPPER TROUGH TO THE W OF THE SURFACE LOW/TROUGH. UPPER-LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT. HOWEVER...CONDITIONS COULD BECOME MORE FAVORABLE AS THE LOW MOVES TOWARD THE N/NW AND A SUBTROPICAL OR TROPICAL CYCLONE COULD FORM DURING THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 20W/21W S OF 19N MOVING W 10-15 KT. BROAD LOW/MID LEVEL CYCLONIC ROTATION COVERING THE AREA FROM 7N-19N BETWEEN 14W-25W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 9N-14N BETWEEN 18W-25W. TROPICAL WAVE IS TILTED FROM 23N44W ALONG 14N47W TO 6N47W MOVING W 10-15 KT. VERY BROAD LOW/MID LEVEL INVERTED-V CURVATURE IS COVERING THE AREA S OF 22N FROM 40W-52W. NO ASSOCIATED DEEP CONVECTION WITH SCATTERED SHOWERS/THUNDERSTORMS FROM 15N-20N BETWEEN 46W-60W. TROPICAL WAVE IS ALONG 78W/79W S OF 19N MOVING W 10-15 KT. WAVE REMAINS EMBEDDED WITHIN SOME RATHER DRY STABLE AIR OVER THE CARIBBEAN MASKING THE SATELLITE SIGNATURE AND LIMITING ANY ASSOCIATED SHOWERS/DEEP CONVECTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 5N29W 9N52W 8N59W. A VERY WEAK NEAR STATIONARY 1014 MB LOW IS NEAR 14N43W AND IS CHARACTERIZED BY A SMALL LOW LEVEL SWIRL WITH NO SHOWER ACTIVITY. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM OF THE ITCZ AXIS E OF 44W TO THE COAST OF W AFRICA. DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE EXTENDS FROM THE TEXAS/LOUISIANA BORDER SE TO W CUBA/YUCATAN CHANNEL INTO THE NW CARIBBEAN COVERING MOST OF THE GULF. A SMALL UPPER HIGH IS NEAR THE REMNANTS OF FELIX THAT ARE JUST INLAND ALONG THE COAST OF S MEXICO NEAR 18.5N95.5W AND CONTINUE TO GENERATE SCATTERED MODERATE/STRONG CONVECTION IN THE W BAY OF CAMPECHE S OF 22N W OF 94W. THE UPPER RIDGE OVER THE GULF COUPLED WITH THE UPPER TROUGH IN THE W ATLC THAT EXTENDS OVER FLORIDA CONTINUES TO GENERATE SCATTERED SHOWERS/ THUNDERSTORMS OVER THE E GULF WITHIN 125/150 NM OF LINE FROM THE N GULF COAST NEAR THE MISSISSIPPI DELTA SW OVER CUBA NEAR HAVANA. THE REMAINDER OF THE AREA REMAINS TRANQUIL THIS MORNING WITH LIGHT SURFACE WINDS. CARIBBEAN SEA... THE UPPER LEVEL RIDGE FROM THE GULF OF MEXICO COVERS THE NW CARIBBEAN N OF 16N W OF 80W AND THE UPPER TROUGH OVER THE W ATLC DIPS ACROSS CUBA TO 18N FROM 75W-81W. THIS IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS N OF 20N FROM 80W-85W. AN UPPER LEVEL TROUGH EXTENDS FROM CENTRAL PANAMA TO OVER CENTRAL NICARAGUA GENERATING SHOWERS/THUNDERSTORMS WITHIN 75/90 NM OF LINE FROM PANAMA NEAR 9N80W TO JUST OVER NICARAGUA NEAR 14N84W. AN UPPER LOW IS JUST N OF HAITI EXTENDS AN UPPER TROUGH OVER THE CENTRAL CARIBBEAN TO 15N FROM 68W-75W GENERATING ISOLATED SHOWERS/THUNDERSTORMS OVER HAITI AND THE GULF OF GONAVE. DRY STABLE AIR COVERS THE REMAINDER OF THE CARIBBEAN E OF 80W IS GIVING THAT AREA CLEAR SKIES WITH THE EXCEPTION OF THE AREAS MENTIONED ABOVE WITH MODERATE/STRONG EASTERLY TRADE WINDS. ATLANTIC OCEAN... AN UPPER TROUGH AXIS EXTENDS INTO THE W ATLC THROUGH 32N72W TO ACROSS CUBA NEAR 22N78W COVERING MOST OF THE W ATLC WITH THE ASSOCIATED 1012 MB LOW AND SURFACE TROUGH MENTIONED IN THE SPECIAL FEATURES ABOVE. A SECOND UPPER LOW IS JUST N OF HAITI EXTENDING A TROUGH S INTO THE CENTRAL CARIBBEAN. THIS FEATURE IS BEING ABSORBED INTO THE UPPER TROUGH OVER THE REMAINDER OF THE W ATLC. A BROAD UPPER HIGH IS IN THE CENTRAL ATLC NEAR 28N52W COVERING THE AREA N OF 20N FROM 30W-67W. A BROAD UPPER TROUGH DIPS INTO THE E ATLC N OF 26N E OF 30W TO OVER NW AFRICA. A WEAK MID/UPPER LOW IS IN THE W TROPICAL ATLC NEAR 14N56W AND COVERS THE AREA S OF 20N FROM 50W ACROSS THE LESSER ANTILLES TO NEAR 63W. THE REMAINDER OF THE TROPICAL ATLC IS DOMINATED BY EASTERLY UPPER FLOW. ALL THESE UPPER FEATURES ARE RATHER BENIGN COUPLED WITH THE ABUNDANCE DRY AIR ALOFT AND A SURFACE RIDGE COVERING THE ATLC E OF 65W ANCHORED BY A 1022 MB HIGH IN THE CENTRAL ATLC NEAR 27N56W AND A 1020 MB HIGH IN THE E ATLC NEAR 27N26W ARE GIVING THE MUCH OF THE ATLC FAIR WEATHER CLOUDS WITH LIGHT TO MODERATE EASTERLY TRADE WINDS. $$ WALLACE