000 AXNT20 KNHC 231136 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE COVERS THE SW CARIBBEAN WITH A 1008 MB LOW ANALYZED NEAR 14N81W AT 23/0900 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 13N-18N BETWEEN 81W-84W 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 13N16W CONTINUING ALONG 10N24W 7N32W TO 6N38W. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN 60 NM N OF THE MONSOON TROUGH BETWEEN 32W-36W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 90/120 NM OF LINE FROM 15N20W TO 8N27W AND WITHIN 120/150 NM OF LINE FROM 8N27W TO 5N36W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-10N BETWEEN 34W-45W. A SURFACE TROUGH IS ANALYZED FROM 16N39W TO 13N47W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 12N-15N BETWEEN 39W-43W AND CLUSTERS OF SIMILAR CONVECTION FROM 9N-12N BETWEEN 42-49W. A 1008 MB LOW IS OFF THE COAST OF SOUTH AMERICA NEAR 11N55W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 9N-12N BETWEEN 52W-57W. ...DISCUSSION... GULF OF MEXICO... NEAR ZONAL WESTERLY FLOW ALOFT CONTINUES TO DOMINATE THE GULF WITH STRONG SUBSIDENCE AND DRY STABLE AIR. A SURFACE TROUGH ALONG 84W BETWEEN 28N AND THE COAST OF CUBA IS EMBEDDED WITHIN SOME LINGERING BROKEN/OVERCAST COLD AIR STRATOCUMULUS CLOUDS THAT COVER THE SE GULF LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES AGAIN THIS MORNING. A SURFACE RIDGE COVERS THE GULF AND THE E CONUS. SURFACE RIDGE WILL REMAIN ACROSS THE W GULF THROUGH WED NIGHT. A 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 WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM E OF THE FRONT S OF 21N. AN UPPER RIDGE IS ANCHORED OVER THE W CARIBBEAN NEAR 17N81W COVERING THE AREA FROM 13N-22N BETWEEN 76W-87W 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 14N76W PROVIDING DIFFLUENCE TO ENHANCE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM 14N74W TO 16N80W LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS MORNING. THE FRONTAL BOUNDARY OVER THE NW CARIBBEAN WILL GRADUALLY DISSIPATE THROUGH TODAY. THE 1008 MB LOW IN THE W TROPICAL ATLC WILL BECOME A SURFACE TROUGH LATER TODAY AND WILL MOVE INTO THE E CARIBBEAN LATE TONIGHT REACHING THE S CENTRAL CARIBBEAN WED THEN MERGING INTO THE MONSOON TROUGH IN THE SW CARIBBEAN THU. ATLANTIC OCEAN... A NEAR STATIONARY FRONTAL BOUNDARY REMAINS OVER THE W ATLC EXTENDING THROUGH 32N70W ALONG 27N76W ACROSS THE BAHAMA ISLANDS TO OVER CUBA NEAR 22N79W AND A SURFACE TROUGH TO THE E EXTENDING FROM 29N69W TO 21N68W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 45 NM EITHER SIDE OF THE FRONT BETWEEN 25N-27N WITH ISOLATED SHOWERS POSSIBLE WITHIN 60 NM EITHER SIDE OF THE REMAINDER OF THE FRONT. A UPPER TROUGH COVERS THE W/CENTRAL ATLC EXTENDING THROUGH 32N65W TO 22N64W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 22N64W TO BEYOND 32N59W. A STRONG UPPER TROUGH EXTENDS S OVER THE E ATLC INTO THE TROPICS TO 15N E OF 47W 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 12N31W ACROSS THE CANARY ISLANDS TO 18N18W. A BROAD SURFACE RIDGE DOMINATES THE ATLC N OF 23N E OF 65W ANCHORED BY A 1024 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