000 AXNT20 KNHC 160543 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED DEC 16 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 0445 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N11W 5N21W 6N37W 3N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN 21W-37W. ...DISCUSSION... GULF OF MEXICO... AS OF 0300 UTC...AN UPPER LEVEL TROUGH EXTENDS FROM THE GREAT LAKES TO THE SOUTHERN PLAINS INTO NW MEXICO SUPPORTING A 1016 MB LOW OFF THE NE MEXICO COASTLINE NEAR 25N96W. A COLD FRONT EXTENDS S FROM THE LOW TO NEAR TAMPICO MEXICO CONTINUING INLAND. A STATIONARY FRONT EXTENDS N OF THE LOW CENTER PARALLELING THE GULF COASTLINE ALONG 27N93W TO E OF PANAMA CITY WHERE IS BECOMES COLD TO SRN SOUTH CAROLINA. A PRE-FRONTAL TROUGH IS AHEAD OF THE COLD FRONT NEAR MEXICO ALONG 23N96W 20N96W. SURFACE CONVERGENCE NEAR THE LOW CENTER AND FRONTAL BOUNDARIES ALONG WITH DIFFLUENT FLOW ALOFT TO THE E SIDE OF THE UPPER TROUGH ARE SUPPORTING NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS WITHIN 60 NM OF THE FRONTAL BOUNDARY W OF 89W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 150 NM OF THE BOUNDARY ELSEWHERE. N-NE WINDS UP TO 30 KT ARE CURRENTLY BEHIND THE FRONT AND ARE FORECAST TO REACH GALE FORCE WITHIN THE NEXT 6 HRS. EXPECT THE COLD PORTION OF THE FRONT ACROSS THE NE GULF TO DIP SWD AS THE LOW REMAINS RELATIVELY STATIONARY UNTIL LATE THURSDAY WHEN IT IS FORECAST TO MOVE E-NE ACROSS THE GULF. CARIBBEAN SEA... STRONG ELY TRADEWINDS CONTINUE ACROSS THE CARIBBEAN AS A RESULT OF A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE W ATLC AND LOW PRESSURE OVER NRN COLOMBIA. THE STRONGEST WINDS...UP TO 30 KT...ARE OFF THE COAST OF COLOMBIA. STRONG SUBSIDENCE AND DRY AIR AROUND AN UPPER LEVEL RIDGE WITH AXIS ALONG 70W DOMINATE THE BASIN SUPPORTING GENERALLY FAIR WEATHER ACROSS THE AREA. HOWEVER...A LINE OF ISOLATED LOW-LEVEL SHOWERS EMBEDDED IN THE ELY SURFACE FLOW ARE MOVING QUICKLY FROM THE LEEWARD ISLANDS TO S OF E CUBA. A FEW ISOLATED SHOWERS ARE ALSO NOTED OFF THE YUCATAN PENINSULA IN THE FAR NW CARIBBEAN. EXPECT LITTLE CHANGE OVER THE NEXT 24 HRS. ATLANTIC OCEAN... A SMALL WEAKNESS OVER CENTRAL FLORIDA IN THE UPPER LEVEL RIDGE EXTENDING FROM THE CARIBBEAN INTO W ATLC IS SUPPORTING A LINE OF SHOWERS/THUNDERSTORMS FROM S OF LAKE OKEECHOBEE FLORIDA TO FORT PIERCE TO N OF FREEPORT BAHAMAS. THE UPPER LEVEL RIDGE SUPPORTS A SURFACE RIDGE COVERING THE W ATLC ANCHORED BY A 1021 MB HIGH NEAR 27N66W. A SHORTWAVE UPPER LEVEL TROUGH OVER THE CENTRAL ATLC SUPPORTS A 1011 MB LOW NEAR 30N44W. A COLD FRONT EXTENDS FROM THE LOW CENTER ALONG 27N45W 27N53W BECOMING A DYING STATIONARY FRONT NEAR 28N59W TO 31N63W. ISOLATED SHOWERS ARE WITHIN 150 NM AHEAD OF THE FRONT BETWEEN 40W-47W...WITH POSSIBLE ISOLATED SHOWERS WITHIN 200 NM OF THE BOUNDARY ELSEWHERE. SCATTERED SHOWERS ARE ALSO E OF THE LOW CENTER N OF 28N BETWEEN 33W-40W. FARTHER E...A DEEP LAYER TROUGH SUPPORTS A DYING COLD FRONT EXTENDING FROM THE CANARY ISLANDS TO NW OF THE CAPE VERDE ISLANDS NEAR 21N30W. ISOLATED SHOWERS ARE POSSIBLE ALONG THE FRONT AXIS. THE UPPER LEVEL TROUGH IS ALSO ENHANCING CONVECTION ALONG THE CENTRAL PORTION OF THE ATLC ITCZ. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ WALTON