000 AXNT20 KNHC 230535 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN OCT 23 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 FEATURES... A BROAD AREA OF LOW PRESSURE COVERS THE SW CARIBBEAN WITH A 1008 MB LOW ANALYZED NEAR 14N81W AT 23/0300 UTC. A REMNANT FRONTAL BOUNDARY REMAINS N OF THIS LOW AND COUPLED WITH LINGERING MOISTURE CONTINUES TO GENERATE SCATTERED/HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS FROM 12N-19N BETWEEN 81W-85W INCLUDING NE NICARAGUA AND HONDURAS. ENVIRONMENTAL CONDITIONS ARE GRADUALLY BECOMING MORE CONDUCIVE FOR DEVELOPMENT OF THIS SYSTEM AND A TROPICAL DEPRESSION COULD FORM LATER TODAY OR TONIGHT. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTHWARD AND THEN NORTHWESTWARD. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINS AND GUSTY WINDS SHOULD CONTINUE TO AFFECT PORTIONS OF HONDURAS AND NICARAGUA THROUGH MONDAY. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS DISTURBANCE THIS AFTERNOON...IF NECESSARY. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W CONTINUING ALONG 10N25W 6N32W TO 6N38W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 120 NM OF LINE FROM 15N18W TO 9N30W AND WITHIN 120/150 NM OF LINE FROM 7N29W TO 2N39W. A SURFACE TROUGH IS ANALYZED FROM 16N37W TO 14N48W WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM S OF THE TROUGH BETWEEN 37W-42W AND WITHIN 60 NM OF N OF THE TROUGH BETWEEN 40W-42W. A 1006 MB LOW IS OFF THE COAST OF SOUTH AMERICA NEAR 11N56W WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 9N-13N BETWEEN 51W-56W. ...DISCUSSION... GULF OF MEXICO... NEAR ZONAL WESTERLY FLOW ALOFT CONTINUES TO DOMINATE THE GULF WITH STRONG SUBSIDENCE AND DRY STABLE AIR. SOME LINGERING COLD AIR STRATOCUMULUS CLOUDS ARE OVER THE SE GULF LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES AGAIN TONIGHT. A SURFACE RIDGE COVERS THE GULF AND THE E CONUS. SURFACE RIDGE WILL REMAIN ACROSS THE W GULF THROUGH WED NIGHT. AN INVERTED TROUGH WILL DEVELOP OVER THE S CENTRAL GULF WED AND MOVE W REACHING ALONG 91W THU NIGHT. CARIBBEAN SEA... THE PRIMARY CONCERN CONTINUES TO BE THE SURFACE LOW IN THE SPECIAL FEATURES SECTION ABOVE. A REMNANT NEAR STATIONARY FRONTAL BOUNDARY REMAINS OVER THE NW CARIBBEAN EXTENDING ACROSS CENTRAL CUBA NEAR 22N79W W OF THE CAYMAN ISLANDS TO 18N84W. AN UPPER RIDGE IS ANCHORED OVER THE W CARIBBEAN NEAR 18N80W COVERING THE AREA FROM 14N-22N BETWEEN 74W-86W FURTHER ENHANCING THE ACTIVITY ASSOCIATED WITH THE LOW IN THE SPECIAL FEATURES. AN UPPER RIDGE COVERS THE REMAINDER OF THE CARIBBEAN EXTENDING FROM THE TROPICAL ATLC ACROSS THE LESSER ANTILLES TO 14N74W PROVIDING DIFFLUENCE TO ENHANCE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 12N-16N BETWEEN 73W-78W LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES TONIGHT. THE FRONTAL BOUNDARY WILL GRADUALLY WASH OUT OVER THE NW CARIBBEAN THROUGH SUN. AN INVERTED TROUGH S OF 14N ALONG 68W WILL MOVE INTO THE E CARIBBEAN SUN NIGHT REACHING THE S CENTRAL CARIBBEAN WED AND THU. ATLANTIC OCEAN... A NEAR STATIONARY FRONTAL BOUNDARY REMAINS OVER THE W ATLC EXTENDING THROUGH 32N69W ALONG 27N76W ACROSS THE BAHAMA ISLANDS TO OVER CUBA NEAR 21N78W AND A SURFACE TROUGH TO THE E EXTENDING FROM 29N68W ALONG 25N69W TO 22N67W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE FRONT. BROKEN COLD AIR STRATOCUMULUS CLOUDS ARE WITHIN 120/150 NM W OF THE FRONT. A UPPER TROUGH COVERS THE W/CENTRAL ATLC EXTENDING THROUGH 32N63W TO 21N63W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120/150 NM OF LINE FROM 22N62W TO BEYOND 32N60W. A STRONG UPPER TROUGH EXTENDS S OVER THE E ATLC INTO THE TROPICS TO 16N E OF 45W SUPPRESSING THE E/W UPPER RIDGE OVER THE TROPICAL ATLC TO THE S AND GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 12N36W ALONG 18N23W TO TO INLAND OVER W AFRICA NEAR 21N17W. A BROAD SURFACE RIDGE DOMINATES THE ATLC N OF 23N E OF 65W ANCHORED BY A 1025 MB HIGH NEAR 35N44W. THE FRONTAL BOUNDARY WILL DRIFT W THROUGH MON. A COLD FRONT WILL ENTER THE NW ATLC SUN NIGHT MERGING WITH THE FRONTAL BOUNDARY MON AND THE MERGED BOUNDARY WILL EXTEND FROM BERMUDA TO THE SE BAHAMAS EARLY TUE MOVING INTO THE CENTRAL ATLC WED. A SURFACE RIDGE WILL EXTEND E TO W ALONG 32N ON THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW