000 AXNT20 KNHC 131725 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 13 2010 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 1715 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 07N12W 06N23W 05N34W 05N42W... AND ALONG 04N46W 05N52W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ANALYZED FROM 01N43W TO 04N44W TO 08N45W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM OF THE AXIS BETWEEN 20W AND 37W. WIDELY SCATTERED WEAK CONVECTION IS FROM 01N-09N BETWEEN 37W AND 49W. ...DISCUSSION... GULF OF MEXICO... STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATES THE GULF... AS WELL AS STRONG N-NW WINDS CONTINUING IN WAKE OF THE FRONT WITH GALE FORCE WINDS LINGERING OVER THE NE GULF THROUGH LATER THIS AFTERNOON. OTHERWISE...A SURFACE RIDGE IS SLOWLY SETTLING IN AND IS EXPECTED TO DRIFT EASTWARD OVER THE CENTRAL GULF THROUGH EARLY TUESDAY USHERING IN A VERY COOL AND DRY CONTINENTAL POLAR AIRMASS. CONDITIONS WILL REMAIN CONSTANT OVER THE NEXT 48 HOURS. CARIBBEAN SEA... A COLD FRONT ENTERS THE DISCUSSION AREA THROUGH EASTERN CUBA EXTENDING SW TO HONDURAS ALONG 21N77W 17N80W 15N86W. SCATTERED SHOWERS ARE WITHIN 45 NM AHEAD OF THE FRONT. GUSTY NW WINDS UP TO 30 KT ARE BEHIND THE FRONT. A DEEP LAYER TROUGH MOVING OFF THE EASTERN CONUS SEABOARD SUPPORTS THIS FRONT. UPPER LEVEL DIFFLUENCE ALONG THE FRONT IS ENHANCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ACROSS THE WINDWARD PASSAGE AND MOST OF HISPANIOLA N OF 18N BETWEEN 70W AND 75W. FARTHER EAST OF THE FRONT...A SHEARLINE EXTENDS ACROSS THE CENTRAL BASIN TO THE PANAMA COAST ALONG 18N75W 13N77W 9N78W. THE AXIS DEPICTS A LINE OF SURFACE CONVERGENCE BETWEEN N-NE WINDS ACROSS THE NW CARIBBEAN AND TRADE WINDS ACROSS THE REMAINDER OF THE BASIN. THE SURFACE CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 150 NM WEST OF THE AXIS. SIMILAR ACTIVITY IS ALONG THE COAST OF COSTA RICA AND WESTERN PANAMA W OF 81...DUE TO NORTHERLY FLOW BANKING UP LOW LEVEL MOISTURE AGAINST THE CENTRAL AMERICA MOUNTAIN RANGE. A SECONDARY AREA OF CONVERGING WINDS IS FOUND NORTH OF COLOMBIA FROM 11N TO 14N BETWEEN 72W AND 76W. DRY STABLE AIR ALOFT IS ELSEWHERE E OF 71W PROVIDING MOSTLY FAIR WEATHER CONDITIONS WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE EASTERLY FLOW. ATLANTIC OCEAN... A DEEP LAYERED TROUGH MOVES OFF THE EASTERN CONUS SEABOARD AND SUPPORTS A COLD FRONT ANALYZED INTO THE W ATLC ALONG 32N69W ACROSS THE SOUTHERN BAHAMAS TO EASTERN CUBA NEAR 21N76W AND INTO THE NW CARIBBEAN SEA. THIS FRONT IS MOVING AT ABOUT 15 TO 18 KT WITH SCATTERED SHOWERS WITHIN 90 NM ON EITHER SIDE OF THE FRONTAL BOUNDARY...AS WELL AS GALE FORCE WINDS WITHIN 240 NM E OF THE FRONT N OF 27N. TO THE EAST OF THE COLD FRONT...LOW-LEVEL CONVERGENCE IS FOCUSED IN THE VICINITY OF A SURFACE TROUGH EXTENDING FROM 26N56W TO 21N57W TO 17N61W SCATTERED WEAK SHOWERS ARE OCCURRING WITHIN 70 NM EITHER SIDE OF THE BOUNDARY. FARTHER EAST... AN UPPER LEVEL SHORTWAVE TROUGH IS OVER THE N CENTRAL ATLC EVIDENT ON WATER VAPOR IMAGERY. THIS UPPER LEVEL TROUGHING SUPPORTS A COLD FRONT ALONG 32N21W 2824 27N30W BECOMING STATIONARY TO 26N40W...GENERATING SCATTERED WEAK SHOWERS OVER A LARGE AREA OF THE CENTRAL ATLC N OF 25N BETWEEN 22W AND 40W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF WEAK SURFACE RIDGING PROVIDING FAIR WEATHER CONDITIONS ACROSS THE AREA. LOOK FOR THE WESTERN ATLC COLD FRONT TO CONTINUE TO MOVE EASTWARD WITH CONVECTION OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SM/FG