000 AXNT20 KNHC 201754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT NOV 20 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 1630 UTC. ...THE ITCZ... ITCZ AXIS IS ANALYZED ALONG 6N10W 5N20W 4N26W 3N32W 4N39W 8N46W 8N52W 6N57W. SCATTERED MODERATE CONVECTION IS FROM 2N-7N BETWEEN 15W-28W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-11N BETWEEN 28W-38W...AND FROM 6N-9N BETWEEN 53W-59W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 12N40W TO 5N43W. ISOLATED MODERATE/STRONG CONVECTION IS WITHIN 90 NM WEST OF THE TROUGH FROM 10N-12N BETWEEN 40W-42W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN COVERS THE AREA GIVING THE ENTIRE GULF SW TO W FLOW ALOFT WITH MODERATE SUBSIDENCE AND MOSTLY DRY STABLE AIR ALOFT AS NOTED IN WATER VAPOR IMAGERY. A BROAD SURFACE RIDGE DOMINATES THE GULF WITH A WEAKNESS IN THE VICINITY OF A SURFACE TROUGH THAT EXTENDS FROM SE MISSISSIPPI ACROSS MOBILE BAY ALABAMA ALONG 29N88W TO 27N89W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH. THIS SURFACE TROUGH IS SUPPORTED BY A SHORT WAVE UPPER TROUGH EXTENDING FROM TENNESSEE TO SOUTHERN TEXAS. A FEW ISOLATED SHOWERS REMAIN ALONG THE NE MEXICAN COAST FROM 20N-26N WEST OF 95W AND ALONG THE COAST IN THE S BAY OF CAMPECHE S OF 20N BETWEEN 91W-95W LEAVING THE REMAINDER OF THE GULF WITH FAIR CONDITIONS THIS AFTERNOON. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A WEAK STATIONARY FRONT REMAINS OVER THE NW CARIBBEAN EXTENDING ACROSS E CENTRAL CUBA ALONG 22N79W 19N84W TO THE GULF OF HONDURAS NEAR 16N87W WITH ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE FRONT. A SHEER LINE PARALLELS THE VENEZUELAN COAST ALONG 13N63W 12N68W 13N72W 12N76W. NE WINDS TO 20 KT ARE NORTH OF THE AXIS WITH WINDS LESS THAN 10 KT TO THE SOUTH. THIS CONVERGENCE OF WIND SPEED IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 150 NM N AND 60NM S OF THE AXIS. ALOFT...UPPER LEVEL RIDGING DOMINATES THE BASIN CENTERED S OF HISPANIOLA BRINGING DRY AIR TO THE REMAINDER OF THE AREA MAINTAINING FAIR CONDITIONS. EXPECT THE FRONTAL BOUNDARY TO DISSIPATE AS SURFACE RIDGING BUILDS S MAINTAINING FRESH NE TRADE WINDS ACROSS MUCH OF THE AREA OVER THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... BROAD UPPER LEVEL TROUGH COVERS THE W ATLC N OF 28N W OF 45W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N46W EXTENDING SW ALONG 25N56W THROUGH THE S BAHAMA ISLANDS NEAR 23N75W BECOMING STATIONARY ACROSS E CENTRAL CUBA INTO THE NW CARIBBEAN. SCATTERED SHOWERS ARE WITHIN 75 NM AHEAD OF THE FRONT. A SHORT WAVE UPPER TROUGH IS ALONG 37W N OF 20N SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 27N43W TO 22N47W AND NO SIGNIFICANT WEATHER. AN UPPER RIDGE EXTENDS FROM 9N27W TO W OF THE CAPE VERDE AND CANARY ISLANDS TOWARD THE AZORES... SUPPORTING A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NE OF THE CANARY ISLANDS. UPPER LEVEL DIFFLUENCE BETWEEN THE AFOREMENTIONED UPPER TROUGH AND UPPER RIDGE SUPPORTING HIGH CLOUDS N OF 20N AND E OF 34W. EXPECT THE COLD FRONT IN THE CENTRAL ATLANTIC TO CONTINUE PUSHING SE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MONTALVO/WALTON