000 AXNT20 KNHC 231704 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON NOV 23 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 6N11W 6N23W 8N32W 5N40W 7N52W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-9N BETWEEN 23W-32W E OF AN EMBEDDED SURFACE TROUGH ALONG 14N34W 5N30W. ISOLATE MODERATE CONVECTION IS FROM 6N-8N BETWEEN 44W-53W. A SECOND EMBEDDED SURFACE TROUGH IS E OF THE LESSER ANTILLES FROM 16N55W TO 6N54W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A SURFACE TROUGH EXTENDS ACROSS CENTRAL FLORIDA ENTERING THE GULF OF MEXICO NEAR FORT MYERS CONTINUING ALONG 25N86W 23N92W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE WITHIN 150 NM SE OF THE TROUGH AXIS...AND WITHIN 200 NM NW OF THE AXIS. SCATTERED SHOWERS/THUNDERSTORMS ARE ALONG THE END OF THE TROUGH AXIS IN THE WRN GULF FROM 22N-25N BETWEEN 90W-96W. THE SHOWER ACTIVITY IS ALSO SUPPORTED BY MOIST SWLY FLOW ALOFT AROUND THE ERN EDGE OF AN UPPER LEVEL TROUGH OVER THE CENTRAL CONUS. A SURFACE RIDGE BUILDS ACROSS THE NRN GULF ANCHORED BY A 1021 MB HIGH S OF LOUISIANA NEAR 29N91W BRINING GENERALLY FAIR WEATHER TO THE NW GULF COASTLINE. EXPECT THE SURFACE TROUGH TO WEAKEN AS HIGH PRESSURE MOVES EASTWARD AHEAD OF THE NEXT COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST TUE. CARIBBEAN SEA... DRY AIR AND SUBSIDENCE IS ACROSS THE CARIBBEAN NOTED IN WATER VAPOR IMAGERY SUPPORTING FAIR WEATHER ACROSS MUCH OF THE BASIN. A FEW SHOWERS/THUNDERSTORMS ARE E OF THE YUCATAN PENINSULA FROM 16N-20N BETWEEN 85W-88W ASSOCIATED WITH A SHORTWAVE UPPER LEVEL TROUGH EXTENDING DOWN THE ERN YUCATAN PENINSULA COAST. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO NOTED N OF JAMAICA NEAR 19N78W. SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE SW CARIBBEAN S OF 12N BETWEEN 77W-84W AFFECTING AREAS OF PANAMA AND COSTA RICA. THIS ACTIVITY IS ENHANCED BY SURFACE CONVERGENCE NEAR THE E PACIFIC ITCZ...AS WELL AS DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH IN THE E PACIFIC AND A BROAD UPPER LEVEL RIDGE THAT COVERS THE CARIBBEAN. FRESH TO STRONG TRADEWINDS ARE ACROSS MUCH OF THE BASIN. EXPECT LITTLE CHANGE OVER THE NEXT 24 HRS. ATLANTIC OCEAN... AS OF 1500 UTC...A WEAK 1018 MB SURFACE LOW IS CENTERED E OF THE NRN COAST OF FLORIDA NEAR 31N77W. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO THE CENTRAL FLORIDA COAST NEAR VERO BEACH AT 28N80W CONTINUING INTO THE GULF OF MEXICO. SCATTERED SHOWERS/THUNDERSTORMS ARE E OF THE TROUGH AXIS N OF 29N BETWEEN 72W-77W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS COVER THE AREA N OF 24N W OF 72W. THIS SHOWER ACTIVITY IS SUPPORTED BY MOIST SWLY AND DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE CENTRAL CONUS AND GULF OF MEXICO AND A BROAD UPPER LEVEL RIDGE COVERING THE WRN ATLC EXTENDING FROM THE CENTRAL CARIBBEAN. A WEAK SURFACE RIDGE AROUND A 1020 MB HIGH NEAR 26N68W COVERS THE REMAINDER OF THE WRN ATLC. A PAIR OF SURFACE TROUGHS ARE IN THE CENTRAL ATLC. THE FIRST EXTENDS FROM 30N56W TO 26N57W. ISOLATED SHOWERS ARE TO THE E OF THE AXIS FROM 25N-29N BETWEEN 51W-55W. THE SECOND TROUGH EXTENDS FROM 31N45W TO 27N49W. STRONG SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM OF THE TROUGH AXIS. BOTH SURFACE TROUGHS ARE SUPPORTED BY A NARROW SHORTWAVE UPPER LEVEL TROUGH WITH AXIS ALONG 50W. AN UPPER LEVEL LOW IS TO THE SE OF THE UPPER TROUGH CENTERED NEAR 23N41W. THE UPPER LOW IS SUPPORTING AN AREA OF CLOUDINESS AND POSSIBLE ISOLATED SHOWERS FROM 12N-24N BETWEEN 30W-39W. THE REMAINDER OF THE ERN ATLC IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1034 MB HIGH N OF THE DISCUSSION AREA NEAR 38N18W. $$ WALTON