000 AXNT20 KNHC 060535 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU SEP 06 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. ...SPECIAL FEATURES... A NON-TROPICAL 1008 MB LOW LOCATED ABOUT 320 NM WSW OF BERMUDA NEAR 30N69W HAS GENERALLY CHANGED LITTLE OVER THE PAST 24 HOURS. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO OVER THE BAHAMAS NEAR 23N77W. THE LOW-LEVEL CENTER IS MOSTLY EXPOSED WITH HEAVIEST SHOWERS/THUNDERSTORMS STRETCHED TO THE E OF THE LOW FROM 28N-32N BETWEEN 65W-69W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FURTHER TO THE E FROM 28N-31N BETWEEN 60W-65W AND WITHIN 60 NM OF LINE FROM 28N68W TO OVER THE BAHAMAS NEAR 23N76W. THE SYSTEM IS INTERACTING WITH AN UPPER LOW THAT IS JUST TO THE NW OF THE SURFACE LOW WHICH IS SHEARING THE SHOWER ACTIVITY TO THE E. UPPER-LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT. HOWEVER...CONDITIONS ARE FORECAST TO BECOME MORE FAVORABLE AS THE LOW MOVES SLOWLY AND ERRATICALLY...AND A SUBTROPICAL OR TROPICAL CYCLONE COULD FORM DURING THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 42W S OF 20N MOVING W 15 KT. VERY BROAD MID LEVEL INVERTED-V CURVATURE IS COVERING THE AREA S OF 24N FROM 30W-47W AND HAS OVERTAKEN THE WEAK 1013 MB LOW EMBEDDED WITHIN THE ITCZ. NO ASSOCIATED DEEP CONVECTION WITH ISOLATED SHOWERS FROM 16N-20N BETWEEN 31W-46W. TROPICAL WAVE IS ALONG 71W S OF 19N MOVING W 10-15 KT. WAVE REMAINS EMBEDDED WITHIN SOME RATHER DRY STABLE AIR OVER THE E CARIBBEAN MASKING THE SATELLITE SIGNATURE AND LIMITING ANY SHOWERS/DEEP CONVECTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 13N34W 8N55W 10N63W. A NEAR STATIONARY WEAK 1013 MB LOW REMAINS EMBEDDED WITHIN THE ITCZ NEAR 12N37W AND CHARACTERIZED BY A SMALL LOW LEVEL SWIRL WITH NO SHOWER ACTIVITY. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 7N-12N E OF 22W TO JUST INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-8N BETWEEN 11W-51W. DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE EXTENDS FROM NEAR T.S. HENRIETTE THAT MADE LANDFALL WEDNESDAY ON THE W COAST OF MEXICO...ACROSS MEXICO AND S TEXAS AND ALONG THE N GULF COAST TO THE CENTRAL FLORIDA PENINSULA COVERING THE N GULF N OF 25N. AN UPPER LOW IS OVER S MEXICO NEAR 20N99W AND EXTENDS AN UPPER TROUGH OVER THE SW GULF S OF 23N W OF 93W. THE REMNANTS OF FELIX ARE INLAND OVER GUATEMALA AND ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE E BAY OF CAMPECHE S OF 21N E OF 94W. AFTERNOON THUNDERSTORMS GENERATED OVER THE FLORIDA PENINSULA HAVE BEEN PUSHED INTO THE E GULF BY MODERATE EASTERLY WINDS AND ARE WITHIN 90 NM ALONG THE COAST OF FLORIDA FROM APALACHEE BAY TO OVER THE FLORIDA KEYS. THE REMAINDER OF THE AREA REMAINS RELATIVELY TRANQUIL WITH POSSIBLE WIDELY ISOLATED LOW LEVEL SHOWERS WITH LIGHT/MODERATE SURFACE WINDS. CARIBBEAN SEA... THE CARIBBEAN IS RELATIVELY QUITE TONIGHT IN THE WAKE OF FELIX. THE REMNANTS OF FELIX ARE INLAND OVER GUATEMALA AND STILL PRODUCING HEAVY SHOWERS/THUNDERSTORMS OVER PORTIONS OF NICARAGUA...HONDURAS...AND THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/THUNDERSTORMS IN THE GULF OF HONDURAS S OF 18N W OF 86W. THE UPPER RIDGE OVER THE E GULF EXTENDS S OVER THE NW CARIBBEAN WHILE A SECOND UPPER RIDGE COVERS THE SW CARIBBEAN. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE OVER CUBA AND THE ADJACENT COASTAL WATERS WITH ISOLATED SHOWERS DOT THE REMAINDER OF THE W CARIBBEAN W OF 75W. AN UPPER LOW IS OVER THE E CARIBBEAN CENTERED NEAR 17N70W DUE TO THE DRY STABLE AIR IS UNABLE TO GENERATE MUCH SHOWER ACTIVITY. THE DRY STABLE AIR COVERS THE E CARIBBEAN E OF 75W WITH MOSTLY CLEAR SKIES WITH THE EXCEPTION OF POSSIBLE ISOLATED LOW LEVEL SHOWERS OVER THE E CARIBBEAN BROUGHT IN BY THE MODERATE EASTERLY TRADE WINDS. ATLANTIC OCEAN... AN UPPER TROUGH COVERS THE W ATLC N OF 24N FROM 68W TO JUST OVER THE FLORIDA PENINSULA WITH AN EMBEDDED UPPER LOW CENTERED NEAR 31N70W AND THE ASSOCIATED 1008 MB LOW AND SURFACE TROUGHS MENTIONED IN THE SPECIAL FEATURES ABOVE. AN UPPER HIGH IS IN THE CENTRAL ATLC NEAR 27N61W. AN UPPER TROUGH DIPS INTO THE E/CENTRAL ATLC THROUGH 32N44W TO 28N42W. A MID/UPPER LOW IS INT HE W TROPICAL ATLC NEAR NEAR 13N52W. THE REMAINDER OF THE ATLC IS DOMINATED BY THE TYPICAL E/W UPPER RIDGE EXTENDING FROM OFF AFRICA TO NEAR 35W CENTERED ROUGHLY ALONG 22W/23W. ALL THESE UPPER FEATURES ARE RATHER BENIGN COUPLED WITH THE ABUNDANCE DRY AIR ALOFT AND A SURFACE RIDGE COVERING THE ATLC E OF 60W ANCHORED BY A 1022 MB HIGH NEAR 27N45W ARE GIVING THE MUCH OF THE ATLC FAIR WEATHER CLOUDS WITH LIGHT TO MODERATE EASTERLY TRADE WINDS. $$ WALLACE