000 AXNT20 KNHC 252338 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI NOV 25 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA ENTERING THE ATLANTIC WATERS NEAR 11N15W TO 7N18W. THE ITCZ CONTINUES FROM 7N18W ALONG 7N30W 5N40W 6N49W. A SURFACE TROUGH IS ANALYZED W OF THE ITCZ ALONG 14N57W TO 7N55W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 200 NM S OF THE ITCZ AXIS BETWEEN 12W-26W...AND WITHIN 100 N OF THE AXIS BETWEEN 22W-36W. SIMILAR ACTIVITY IS FROM 4N-12N BETWEEN 42W-56W TO THE E OF THE SURFACE TROUGH. ...DISCUSSION... GULF OF MEXICO... DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE EXTENDING FROM THE BAY OF CAMPECHE TO LOUISIANA AND UP THE ERN CONUS CONTINUES TO PROVIDE FAIR WEATHER TO MUCH OF THE GULF OF MEXICO THIS EVENING. SURFACE RIDGING AROUND A 1029 MB HIGH OVER NE GEORGIA IS SUPPORTING ANTI-CYCLONIC SURFACE FLOW OF 15-20 KTS IN THE NE GULF. THE WEAKENING REMNANTS OF A FRONTAL BOUNDARY ARE STILL PRODUCING A FEW SHOWERS IN THE SRN GULF FROM 23N-25N BETWEEN 85W-92W NEAR A DISSIPATING STATIONARY FRONT EXTENDING ACROSS CUBA TO NEAR 23N89W...AND A SURFACE TROUGH EXTENDING FROM THAT POINT TO THE SRN BAY OF CAMPECHE. CLUSTERS OF STRATOCUMULUS CLOUDS DOT THE REMAINDER OF THE BASIN. EXPECT THE FRONTAL BOUNDARY TO CONTINUE TO DISSIPATE WHILE FAIR AND WINDY CONDITIONS REMAIN ACROSS THE REMAINDER OF THE BASIN. THE NEXT FRONTAL BOUNDARY WILL ENTER THE NE GULF LATE SATURDAY/EARLY SUNDAY. CARIBBEAN SEA... DRY AIR ALOFT AROUND THE BASE OF A BROAD UPPER LEVEL TROUGH OVER THE WRN ATLC IS KEEPING THE NW CARIBBEAN UNDER MOSTLY FAIR CONDITIONS. A DISSIPATING STATIONARY FRONT EXTENDS ACROSS CUBA ALONG 21/22N WITH ONLY POSSIBLE ISOLATED SHOWERS DUE TO THE STRONG DRY AIR ALOFT. DRY AIR CONTINUES ACROSS THE EXTREME NRN CARIBBEAN. HOWEVER...THE SRN PORTIONS OF THE BASIN ARE IMPACTING BY DEEP LAYER MOISTURE. BROAD SURFACE CYCLONIC FLOW IS PRESENT AROUND AN ACTIVE MONSOON TROUGH EXTENDING FROM CENTRAL COSTA RICA TO NRN COLOMBIA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 16N BETWEEN 65W-83W. THE MOISTURE IS EXPECTED TO REMAIN ACROSS THE SRN CARIBBEAN EMBEDDED WITHIN THE CYCLONIC FLOW PRESENT. THE LESSER ANTILLES CAN ALSO EXPECT AN INCREASE IN SHOWER ACTIVITY AS MOISTURE ASSOCIATED WITH A SURFACE TROUGH E OF THE ISLANDS BEGINS TO ADVECT WWD. ATLANTIC OCEAN... A TILTED UPPER LEVEL TROUGH OVER THE WRN ATLC ALONG 34N60W TO WRN CUBA CONTINUES TO SUPPORT A COLD FRONT ALONG 32N53W TO 25N65W CONTINUING AS A DISSIPATING COLD FRONT TO ERN CUBA NEAR 21N77W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM EITHER SIDE OF THE AXIS. SURFACE RIDGING AROUND A 1029 MB HIGH OVER NE GEORGIA IS PROVIDING FAIR AND WINDY CONDITIONS W OF THE FRONT. TO THE E...ANOTHER WEAK SURFACE RIDGE IS AROUND A 1019 MB HIGH NEAR 30N43W SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING FROM THE NE CARIBBEAN TO NEAR 33N43W. AN UPPER LEVEL LOW NEAR 31N33W SUPPORTS A 1012 MB SURFACE LOW NEAR 34N36W. AN ASSOCIATED STATIONARY FRONT ENTERS THE DISCUSSION AREA NEAR 32N30W ALONG 27N30W 23N36W DISSIPATING TO 21N42W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM W OF THE AXIS N OF 26N WITH ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE AXIS ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON