000 AXNT20 KNHC 250001 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE NOV 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2300 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N12W 6N25W 8N40W 7N50W 8N60W. AN EMBEDDED SURFACE TROUGH IS ALONG THE ITCZ AXIS FROM 16N40W TO 6N42W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS E OF THE TROUGH AXIS FROM 1N-8N BETWEEN 21W-37W. ISOLATED MODERATE CONVECTION IS ALONG THE TROUGH AXIS..AND E OF THE AXIS FROM 8N-17N BETWEEN 27W-37W. AN UPPER LEVEL TROUGH WITH AXIS ALONG 42W IS PROVIDING A DIFFLUENT ZONE ALOFT WHICH IS ENHANCING THE LARGE AREA OF CONVECTION E OF THE SURFACE TROUGH AND ALONG THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A LARGE AREA OF ACTIVE WEATHER REMAINS ACROSS THE WRN GULF OF MEXICO TONIGHT. AS OF 2100 UTC...A COLD FRONT EXTENDS OFF THE TEXAS COAST STRETCHING FROM 30N93W NEAR LAKE CHARLES LOUISIANA TO 25N98W S OF BROWNSVILLE TEXAS CONTINUING NW ALONG THE SIERRA MADRE MOUNTAINS TO NEAR 27N102W. RECENT LIGHTNING AND RADAR DATA INDICATE NUMEROUS SHOWERS/THUNDERSTORMS JUST S OF BROWNSVILLE IN THE NERN TIP OF MEXICO FROM 24N-26N BETWEEN 97W-100W. LIGHTNING DATA ALSO INDICATES ACTIVE THUNDERSTORMS S OF THE CENTRAL LOUISIANA COAST FROM 26N-29N BETWEEN 91W-93W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS COVER MOST OF THE N AND CENTRAL GULF FROM 25N-29N BETWEEN 88W-96W. A STATIONARY FRONT IS AHEAD OF THIS LARGE AREA OF SHOWER ACTIVITY EXTENDING FROM CENTRAL FLORIDA ENTERING THE GULF OF MEXICO AT 27N82W N OF FORT MYERS CONTINUING INTO THE CENTRAL GULF ALONG 26N87W 23N94W. LIGHTNING DATA INDICATES NUMEROUS SHOWERS/THUNDERSTORMS ALONG THE SRN PORTION OF THE FRONT FROM 22N-25N BETWEEN 90W-94W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO WITHIN 60 NM OF THE FRONT AXIS. THIS ENTIRE SYSTEM IS SUPPORTED BY A LONGWAVE UPPER LEVEL TROUGH OVER THE CENTRAL CONUS WITH AXIS EXTENDING SWD OVER THE FAR WRN GULF. SIGNIFICANT UPPER LEVEL MOISTURE ALONG WITH DIFFLUENT FLOW ALOFT AROUND THE ERN SIDE OF THE UPPER TROUGH IS ACROSS THE BASIN SUPPORTING THE LARGE AREA OF SHOWER ACTIVITY. SURFACE WINDS OF 20-25 KT ARE BEHIND THE COLD FRONT. EXPECT SHOWERS/THUNDERSTORMS TO CONTINUE OVER THE MAJORITY OF THE GULF AS THE COLD FRONT PUSHES SE. CARIBBEAN SEA... SUBSIDENCE AND DRY AIR REMAINS ACROSS THE MAJORITY OF THE CARIBBEAN SEA NOTED IN WATER VAPOR IMAGERY SUPPORTING FAIR WEATHER ACROSS MUCH OF THE BASIN. A FEW ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE ACROSS THE YUCATAN PENINSULA AND WRN CUBA ASSOCIATED WITH MOIST AND DIFFLUENT WSW FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE CENTRAL CONUS AND WRN GULF AND AN UPPER LEVEL RIDGE COVERING THE CARIBBEAN EXTENDING INTO THE WRN ATLC. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS THE SW CARIBBEAN S OF 13N BETWEEN 78W-85W AFFECTING MOST OF PANAMA...COSTA RICA...AND ERN NICARAGUA ENHANCED BY SURFACE CONVERGENCE NEAR THE E PACIFIC ITCZ. A FEW ISOLATED SHOWERS ARE NOTED OVER JAMAICA...CENTRAL HISPANIOLA...AND THE FAR SW CARIBBEAN. FRESH TO STRONG TRADEWINDS ARE ACROSS THE MAJORITY OF THE BASIN WITH THE STRONGEST WINDS OFF THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HRS. ATLANTIC OCEAN... A STATIONARY FRONT EXTENDS ACROSS THE WRN ATLC FROM 31N73W ALONG 29N76W TO THE CENTRAL FLORIDA COAST AT 28N80W NEAR MELBOURNE CONTINUING INTO THE GULF OF MEXICO. SCATTERED SHOWERS/THUNDERSTORMS ARE JUST OFF THE FLORIDA COAST FROM 28N-29N BETWEEN 77W-82W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE ACROSS THE WRN ATLC N OF 22N W OF 68W. THIS ACTIVITY IS SUPPORTED BY A MOIST AIR MASS EXTENDING FROM THE GULF OF MEXICO AROUND AN UPPER LEVEL RIDGE STRETCHING FROM THE CENTRAL CARIBBEAN TO THE NE UNITED STATES COASTLINE NEAR 37N75W. IN THE CENTRAL ATLC...A 1011 MB LOW IS ANALYZED NEAR 27N54W. A SURFACE TROUGH EXTENDS TO THE SW FROM THE LOW CENTER TO NEAR 22N59W. A SECOND SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO THE NE ALONG 28N47W TO A SECOND 1012 MB LOW CENTER NEAR 32N41W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 250 NM S OF THIS TROUGH AXIS. TO THE N..A DYING COLD FRONT EXTENDS FROM THE 1012 MB LOW CENTER AT 32N41W TO 29N50W CONTINUING AS A DYING STATIONARY FRONT TO 32N63W. ISOLATED SHOWERS ARE ALONG THIS FRONT AXIS. A NARROW SHORTWAVE UPPER LEVEL TROUGH WITH AXIS ALONG 36N65W 26N52W SUPPORTS THE 1011 MB LOW...WHILE A SECOND LONGER WAVE UPPER LEVEL TROUGH CENTERED NEAR 22N42W SUPPORTS THE 1012 MB LOW AND THE SURFACE TROUGH CONNECTING THE TWO SURFACE LOWS. THE LONGWAVE UPPER LEVEL TROUGH IS ALSO ENHANCING SHOWER ACTIVITY ALONG THE ERN HALF OF THE ITCZ. $$ WALTON