000 AXNT20 KNHC 241747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU NOV 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1735 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WRN AFRICA THROUGH GUINEA ENTERING THE ATLC WATERS ALONG 10N14W TO 8N17W. THE ITCZ AXIS EXTENDS FROM 8N17W ALONG 5N30W TO 4N45W. A SURFACE TROUGH IS ANALYZED W OF THE ITCZ FROM 15N48W TO 4N52W WITH SCATTERED MODERATE CONVECTION WITHIN 30-60 NM EITHER SIDE OF THE TROUGH AXIS. SIMILAR CONVECTION IS WITHIN 100-150 NM EITHER SIDE OF THE ITCZ. ...DISCUSSION... GULF OF MEXICO... A COOL/DRY AIRMASS MADE ITS WAY ACROSS MOST OF THE GULF DURING THE OVERNIGHT HOURS AND THROUGHOUT THIS MORNING...IN THE WAKE OF A COLD FRONT EXTENDING ACROSS THE ERN AND SRN GULF THROUGH THE FLORIDA STRAITS ALONG 24N81W TO 24N89W...BECOMING STATIONARY FROM THIS POINT TO COASTAL COATZACOALCOS MEXICO ALONG 21N93W TO 18N94W. VISIBLE SATELLITE IMAGERY SHOWS VERY LIMITED CONVECTION ALONG THE ENTIRE BOUNDARY...WITH ONLY A FEW ISOLATED SHOWERS WITHIN 20 NM ON EITHER SIDE OF IT. LOW LEVEL STRATOCUMULUS CLOUDS COVER THE GULF N OF THE BOUNDARY. AS THE CONVECTION IN THE VICINITY OF THE BOUNDARY IS EXPECTED TO LINGER OVER THE NEXT 24 HOURS...COMPUTER MODELS SUGGEST THIS BOUNDARY WILL TRANSITION TO A SHEAR LINE AXIS DURING THE FORECAST PERIOD...WITH ENE WINDS UP TO 25 KT N OF THE AXIS E OF 87W. IN THE UPPER LEVELS...MOSTLY DRY WESTERLY ZONAL FLOW ALOFT IS OBSERVED ACROSS THE ENTIRE GULF ON WATER VAPOR IMAGERY. CARIBBEAN SEA... WATER VAPOR IMAGERY DISPLAYS A VERY DRY UPPER ATMOSPHERE ACROSS THE NW BASIN W OF A LINE EXTENDING FROM 18N74W TO 15N84W... PROVIDED BY AN UPPER ANTICYCLONIC CIRCULATION CENTERED OVER THE YUCATAN PENINSULA...SUPPRESSING CONVECTION IN THIS REGION. ANOTHER ANTICYCLONIC CIRCULATION CENTERED OVER THE FAR ERN TROPICAL ATLC IS PROVIDING MOIST S-SW FLOW ALOFT ELSEWHERE ACROSS THE DISCUSSION AREA. THIS CONDITION ALONG WITH A BROAD LOW LEVEL MOIST CYCLONIC WIND FIELD IS GENERATING CLUSTERS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS E OF A LINE EXTENDING FROM 8N74W TO 15N84W. A SURFACE TROUGH IS JUST E OF THE LESSER ANTILLES ANALYZED FROM 15N59W TO 9N61W ENHANCING THE CONVECTION OVER THE FAR ERN BASIN S OF 16N E OF 64W. ANOTHER REGION OF ENHANCED CONVECTION IS THE FAR SW BASIN...IN THE VICINITY OF THE MONSOON TROUGH EXTENDING ACROSS CENTRAL AMERICA ALONG COSTA RICA INTO NRN COLOMBIA. CONDITIONS ARE EXPECTED TO REMAIN CONSTANT DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH MOVES ACROSS THE WRN ATLC THIS AFTERNOON ...SUPPORTING A COLD FRONT THAT ENTERS OUR REGION ALONG 32N66W AND CONTINUES SW ALONG 28N70W ACROSS THE NRN BAHAMAS OVER NASSAU AND INTO THE FLORIDA STRAITS ALONG 24N81W. VISIBLE SATELLITE IMAGERY INDICATED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 30 NM EITHER SIDE OF THE FRONT. A BROAD AND FAIRLY STRONG SURFACE RIDGE ANCHORED IN THE SE CONUS MOVES INTO THE WRN ATLC AS THE COLD FRONT CONTINUES TO TRACK EASTWARD. A FEW CLUSTERS OF SCATTERED WEAK SHOWERS ARE FARTHER E OF THE FRONT N OF 23N BETWEEN 58W-67W...MOVING SOUTH-SOUTHWESTERLY ALONG THE SW CORNER OF A BROAD/ELONGATED SURFACE RIDGE ANCHORED N OF THE AREA... KEEPING FAIR WEATHER ACROSS THE CENTRAL ATLC. AN UPPER LEVEL TROUGH/OCCLUDED LOW IS OVER THE ERN ATLC REFLECTING A 1001 MB LOW CENTERED NEAR 34N32W. SATELLITE IMAGERY OVER THE PAST FEW HOURS INDICATES THE SYSTEM HAS TAKEN A WESTWARD MOTION. A COLD FRONT EXTENDS S FROM THE OCCLUSION POINT N OF THE LOW INTO OUR AREA ALONG 32N28W AND CONTINUES SW ALONG 26N33W TO 24N36W... DISSIPATING TO NEAR 23N43W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE N OF 24N BETWEEN THE FRONT AND 23W. THIS SYSTEM IS PRODUCING STORM-LIKE WINDS ON THE NE QUADRANT N OF THE DISCUSSION AREA. FAIR WEATHER CONDITIONS ARE ELSEWHERE E OF 24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA