000 AXNT20 KNHC 030546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU DEC 03 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 5N30W 4N51W. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM OF THE AXIS BETWEEN 26W-44W. ...DISCUSSION... GULF OF MEXICO... AS OF 0300 UTC...A COLD FRONT EXTENDS OVER NE FLORIDA AND THE FLORIDA BIG BEND REGION INTO THE NE GULF NEAR 29N83W CONTINUING SW ALONG 26N86W 22N90W WHERE IT TRANSITIONS STATIONARY TO THE SOUTHERN MEXICO COAST NEAR 18N95W. A PRE-FRONTAL TROUGH IS LOCATED 60/90 NM EAST OF THE FRONT FROM THE CENTRAL FLORIDA PENINSULA TO THE YUCATAN PENINSULA. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE A LINE OF SCATTERED SHOWERS AND TSTMS WITHIN 120 NM EAST OF THE SURFACE TROUGH WITH LINGERING ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE COLD FRONT. THESE BOUNDARIES ARE BEING SUPPORTED BY AN UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER THE MID-ATLC STATES. AS THE FRONT CONTINUES MOVING EASTWARD AND EXITS THE GULF REGION...THE NEXT UPPER LEVEL SHORTWAVE TROUGH AXIS CURRENTLY LOCATED OVER THE SW CONUS WILL DEVELOP LOW PRESSURE OVER THE NW GULF LATE FRIDAY. THE ASSOCIATED COLD FRONT WILL USHER IN STRONG NORTHERLY WINDS TO GALE FORCE BEHIND THE FRONT THROUGH EARLY SATURDAY. CARIBBEAN SEA... A BROAD UPPER LEVEL RIDGE COVERS THE CARIBBEAN ANCHORED IN THE E PACIFIC EXTENDING ACROSS CENTRAL AMERICA OVER EASTERN CUBA AND INTO THE W ATLC. STRONG SUBSIDENCE AND THE LACK OF MOISTURE IS NOTED ON WATER VAPOR IMAGERY WHICH ACCOMPANIES THE UPPER LEVEL ANTICYCLONIC CIRCULATION BRINGING TRANQUIL WEATHER AND FAIR SKIES TO MUCH OF THE BASIN. HOWEVER...A FEW ISOLATED SHOWERS ARE BEING USHERED IN ON FRESH TO STRONG TRADEWINDS ACROSS THE CARIBBEAN SEA AND LESSER ANTILLES MAINLY E OF 70W. ALSO...A FEW ISOLATED SHOWERS ARE IN THE SW CARIBBEAN AND ALONG THE COASTS OF WESTERN PANAMA...COSTA RICA... AND EXTREME SOUTHERN NICARAGUA SW OF A LINE FROM 12N84W TO 9N80W. ATLANTIC OCEAN... A COLD FRONT EXTENDS ACROSS THE EXTREME W ATLC FROM INLAND ACROSS THE CAROLINAS TO NEAR JACKSONVILLE FLORIDA. SCATTERED SHOWERS AND TSTMS ARE OVER THE W ATLC N OF 27N W OF 75W. THIS FRONTAL BOUNDARY IS SUPPORTED ALOFT BY AN UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER THE MID-ATLC STATES. UPPER LEVEL DIFFLUENCE BETWEEN THE TROUGH AND A BROAD UPPER LEVEL RIDGE EXTENDING FROM THE WESTERN CARIBBEAN ACROSS EASTERN CUBA TO BEYOND 32N65W IS ENHANCING THE CONVECTION. THE REMAINDER OF THE W ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH NE OF BERMUDA NEAR 36N61W. HOWEVER... POCKETS OF ISOLATED SHOWERS ARE FROM 20N-24N BETWEEN 53W-64W AND FROM 24N-28N BETWEEN 68W-73W. FARTHER EAST...A NARROW UPPER LEVEL TROUGH AXIS EXTENDS S ALONG 44W TO 16N AND SUPPORTS A SURFACE TROUGH THAT EXTENDS FROM 17N49W TO BEYOND 32N43W. SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE WITHIN 300 NM E OF THE SURFACE TROUGH AXIS. THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED OVER THE AZORES. $$ HUFFMAN