000 AXNT20 KNHC 220541 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT OCT 22 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE... A BROAD AREA OF LOW PRESSURE COVERS THE SW CARIBBEAN WITH A 1007 MB LOW ANALYZED NEAR 13N81W. LINGERING TROPICAL MOISTURE IS GENERATING SCATTERED/HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS S OF 14N W OF 80W TO THE COAST OF CENTRAL AMERICA. ALTHOUGH THERE HAS BEEN LITTLE CHANGE IN THE ORGANIZATION DURING THE PAST SEVERAL HOURS...UPPER LEVEL WINDS ARE FORECAST TO BE FAVORABLE FOR THE DEVELOPMENT OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT DRIFTS SLOWLY NORTHWARD. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 15N17W CONTINUING ALONG 13N23W TO 8N28W. THE ITCZ AXIS CONTINUES FROM 8N28W TO 11N41W. CLUSTERS OF SCATTERED MODERATE/ STRONG CONVECTION ARE FROM 2N-6N BETWEEN 3W-17W INCLUDING THE COAST OF SW AFRICA. A SURFACE TROUGH IS ANALYZED FROM A 1010 MB LOW NEAR 21N38W ALONG 16N43W TO 12N49W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 90/120 NM OF LINE FROM 17N36W TO 12N43W. A 1006 MB LOW IS ALSO IN THE TROPICS OFF THE COAST OF SOUTH AMERICA NEAR 9N57W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WELL REMOVED FROM THE LOW COVERING THE AREA FROM 2N-16N BETWEEN 44W-55W. ...DISCUSSION... GULF OF MEXICO... THE BROAD UPPER TROUGH THAT SWEPT THROUGH THE GULF HAS LEFT NEAR ZONAL WESTERLY FLOW ALOFT OVER THE GULF TONIGHT. STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATE THE GULF WITH SOME LINGERING COLD AIR STRATOCUMULUS CLOUDS ARE OVER THE FAR S GULF LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES AGAIN TONIGHT. A SURFACE RIDGE COVERS THE GULF AND THE E CONUS WITH A 1022 MB HIGH OVER MISSISSIPPI. SURFACE RIDGE WILL CONTINUE TO BUILD ACROSS THE W GULF THROUGH WED. CARIBBEAN SEA... THE PRIMARY CONCERN TONIGHT IS THE SURFACE LOW IN THE SPECIAL FEATURES SECTION ABOVE. THE BROAD UPPER TROUGH OVER CENTRAL ATLC EXTENDS OVER THE A MAJOR PORTION OF THE CARIBBEAN INDUCING AN INVERTED UPPER TROUGH OVER THE NW CARIBBEAN FROM NE HONDURAS TO OVER THE CAYMAN ISLANDS. THE REMNANTS OF A STATIONARY FRONTAL BOUNDARY REMAIN ACROSS THE NW CARIBBEAN EXTENDING OVER CUBA NEAR 21N78W JUST W OF THE CAYMAN ISLANDS TO JUST OFF THE COAST OF HONDURAS NEAR 16N84W. LINGERING MOISTURE COUPLED WITH THE SURFACE AND UPPER LEVEL FEATURES ARE GENERATING HEAVY SHOWERS AND SCATTERED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM THE CAYMAN ISLANDS ALONG 17N83W TO NE NICARAGUA NEAR 14N84W. THE BROAD UPPER TROUGH IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE CENTRAL AND E CARIBBEAN S OF 19N TO ALONG COAST OF COLOMBIA AND VENEZUELA BETWEEN 64W-78W. REMNANTS OF THE FRONT WILL MEANDER ACROSS THE NW CARIBBEAN THROUGH SUN. A TROUGH OVER THE TROPICAL ATLC WILL MOVE W INTO THE E CARIBBEAN MON REACHING THE CENTRAL CARIBBEAN WED. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE E CONUS EXTENDS OVER THE W ATLC W OF 72W SUPPORTING A STATIONARY FRONT THAT EXTENDS THROUGH 32N69W ALONG 27N72W ACROSS THE BAHAMA ISLANDS NEAR 24N75W TO OVER CUBA NEAR 21N78W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM W OF THE FRONT S OF 26N AND WITHIN 120 NM E OF THE FRONT FROM THE BAHAMAS TO OVER CUBA. COLD AIR STRATOCUMULUS CLOUDS ARE WITHIN 200 NM W OF THE FRONT. THE SURFACE RIDGE OVER THE GULF OF MEXICO EXTENDS E TO THE FRONT. A BROAD UPPER LOW/TROUGH COVERS THE REMAINDER OF THE W ATLC AND ALL OF THE CENTRAL ATLC CENTERED NEAR 20N62W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 19N-30N BETWEEN 54W-67W. AN UPPER TROUGH EXTENDS S TO OVER THE E ATLC N OF 23N E OF 35W. A BROAD E/W UPPER RIDGE COVERS THE TROPICAL ATLC S OF 21N E OF 58W PROVIDING DIFFLUENCE BETWEEN THIS UPPER RIDGE AND THE ABOVE UPPER TROUGH TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM 25N28W TO OVER THE CANARY ISLANDS NEAR 28N16W. A BROAD SURFACE RIDGE DOMINATES THE ATLC N OF 25N E OF THE FRONT TO AFRICA. THE STATIONARY FRONT WILL DRIFT W THROUGH MON. A COLD FRONT WILL MOVE SE ACROSS THE NW ATLC SUN NIGHT MERGING WITH THE FRONTAL TROUGH MON AND THE MERGED FRONT WILL EXTEND FROM BERMUDA TO THE SE BAHAMAS MON NIGHT THEN MOVE INTO THE CENTRAL ATLC BY EARLY WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW