000 AXNT20 KNHC 271732 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT NOV 27 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 8N11W 5N22W 7N40W 10N62W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 120 NM EITHER SIDE OF THE ITCZ 42W-54W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH AXIS STRETCHES FROM THE E CONUS TO OVER THE NW GULF WATERS N OF LINE FROM TAMPA FLORIDA TO TUXPAN MEXICO SUPPORTING A COLD FRONT THAT AT 27/1500 UTC EXTENDS INTO THE E GULF NEAR FORT MYERS FLORIDA ALONG 23N91W TO 21N92W BECOMING STATIONARY TO THE COAST OF S MEXICO NEAR 18N93W. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATES MOST OF THE GULF LEAVING THE FRONT LACKING ANY SIGNIFICANT DEEP CONVECTION BUT WITH LOW LEVEL SCATTERED SHOWERS WITHIN 45 NM EITHER SIDE OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 23N87W OVER THE YUCATAN PENINSULA OVER MERIDA TO THE NW CORNER OF GUATEMALA AND ISOLATED SHOWERS WITHIN 45 NM EITHER SIDE OF THE TROUGH. BAND OF DENSE LOW LEVEL CLOUD COVER IS WITHIN 120 NM W OF THE FRONT LEAVING THE N GULF UNDER CLEAR SKIES THIS AFTERNOON. BROAD UPPER RIDGE THAT COVERS THE CARIBBEAN EXTENDS OVER THE FAR SE GULF. E OF THE COLD FRONT IS LOW LEVEL CONVERGENCE AND WEAK SURFACE TROUGHING IS PROVIDING FOR ISOLATED SHOWERS OVER THE SE GULF AND THE STRAITS OF FLORIDA THIS MORNING S OF 25N E OF 84W. CARIBBEAN SEA... UPPER LEVEL RIDGE EXTENDS ACROSS THE CARIBBEAN ANCHORED JUST W OF THE WINDWARD ISLANDS NEAR 12N60W ALONG 13N75W TO OVER THE YUCATAN PENINSULA NEAR 19N88W. MOST OF THE MID/UPPER LEVEL MOISTURE IS LOCATED S OF THIS AXIS E OF 84W WHILE STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT N OF THIS AXIS ACROSS THE GREATER ANTILLES INTO THE W ATLC. THE UPPER RIDGE IS PROVIDING A DIFFLUENT ENVIRONMENT ALOFT OVER MUCH OF THE S CARIBBEAN S OF 14N GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 13N TO INLAND OVER VENEZUELA BETWEEN 65W-70W AND S OF 13N TO JUST INLAND OVER PANAMA AND COSTA RICA W OF 76W TO THE COAST OF NICARAGUA. THIS IS LEAVING THE NW CARIBBEAN UNDER CLEAR SKIES THIS AFTERNOON. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE N GULF OF MEXICO EXTENDS OVER THE NW ATLC SUPPORTING A COLD FRONT THAT ENTERS THE REGION AT 27/1500 UTC FROM 32N72W ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR MELBOURNE. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC IS UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE WITH AXIS EXTENDING FROM THE UPPER HIGH JUST W OF THE WINDWARD ISLANDS NEAR 12N60W N 26N59W TO BEYOND 32N56W WITH A SURFACE RIDGE COVERING THE AREA BETWEEN 50W-75W ANCHORED BY A 1019 MB HIGH NEAR 27N61W. THIS IS GIVING THE AREA FAIR WEATHER THIS AFTERNOON. HOWEVER...SATELLITE IMAGERY INDICATES POSSIBLE LOW LEVEL ISOLATED SHOWERS OVER THE FAR W ATLC FROM 23N-27N W OF 78W TO OVER THE FLORIDA PENINSULA AND A BAND OF LOW LEVEL FAST MOVING CLOUDS WITH ISOLATED SHOWERS WITHIN 60/75 NM OF LINE FROM N OF PUERTO RICO NEAR 19N66W TO E OF THE BAHAMA ISLANDS NEAR 24N73W. AN UPPER TROUGH IS OVER THE E ATLC N OF 20N BETWEEN 20W-45W SUPPORTING ANOTHER COLD FRONT THAT ENTERS THE E ATLC NEAR 32N30W ALONG 29N29W TO 20N40W WHERE IT DISSIPATES TO NEAR 18N55W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90/120 NM OF LINE FROM 22N35W TO 30N24W THEN BEYOND 32N25W. ELSEWHERE...A WEAK SURFACE RIDGE COVERS THE REMAINDER OF THE E ATLC ANCHORED BY A 1014 MB HIGH NEAR 20N20W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW