000 AXNT20 KNHC 231749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED NOV 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 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 10N15W TO 9N20W. THE ITCZ AXIS EXTENDS FROM 9N20W ALONG 5N30W TO 6N42W. A SURFACE TROUGH IS ANALYZED W OF THE ITCZ 13N44W TO 5N47W WITH ISOLATED WEAK CONVECTION WITHIN 30 NM EITHER SIDE OF THE TROUGH AXIS. SCATTERED MODERATE CONVECTION IS WITHIN 100-150 NM EITHER SIDE OF THE ITCZ. ANOTHER SURFACE TROUGH IS MOVING NEAR THE COASTAL WATERS OF GUYANA...ANALYZED FROM 12N55W TO 8N59W. ISOLATED MODERATE CONVECTION IS WELL REMOVED TO THE W OF THE AXIS AFFECTING THE ISLAND OF ADJACENT WATERS OF TRINIDAD AND TOBAGO. ...DISCUSSION... GULF OF MEXICO... MOSTLY DRY WESTERLY ZONAL FLOW ALOFT IS OBSERVED ACROSS THE GULF ON WATER VAPOR IMAGERY THIS AFTERNOON. HOWEVER...AN UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE ERN CONUS REACHING DOWN TO THE FAR NORTHERN GULF COAST WATERS SUPPORTING A COLD FRONT CURRENTLY ANALYZED FROM THE NRN FLORIDA PENINSULA TO THE MEXICO COAST S OF TAMPICO ALONG 30N83W 25N91W TO 20N97W. FROM SATELLITE VISIBLE IMAGERY...A THIN CLOUD LINE DENOTES THE FRONTAL BOUNDARY WITH VERY LIMITED CONVECTION S OF 27N. TO THE N OF 27N...DOPPLER RADAR IMAGERY INDICATED HEAVY SHOWERS AND THUNDERSTORMS AHEAD OF THE BOUNDARY WITHIN 100 NM HEADING INLAND INTO THE FLORINA PENINSULA. MARINE OBSERVATIONS ACROSS THE AREA SHOW SURFACE SSW FLOW UP TO 15 KT IS AHEAD OF THE FRONT...WHILE A NORTHERLY COMPONENT UP TO 20 KT BEHIND THE FRONT. COMPUTER MODELS SUGGEST THE FRONT WILL CONTINUE TO MOVE INTO THE WRN ATLC BASIN WHILE THE SRN EXTENSION OF THE BOUNDARY BECOMES STATIONARY WITH SOME WEAK TO MODERATE CONVECTION LINGERING OVER THE SRN AND SW GULF WITHIN THE NEXT 24 HOURS. CARIBBEAN SEA... WATER VAPOR IMAGERY DISPLAYS A VERY DRY UPPER ATMOSPHERE W OF A LINE EXTENDING FROM ERN HISPANIOLA NEAR 18N69W TO THE COAST OF NICARAGUA NEAR 12N83W. THIS UPPER AIRMASS IS SUPPRESSING CONVECTION IN THIS REGAIN. A BROAD SURFACE CYCLONIC WIND FIELD IS TO THE E OF THIS LINE WITH PLENTY OF LOW-MID LEVEL MOISTURE NOTICED ON TOTAL PRECIPITABLE WATER IMAGERY. THIS PATTERN IS GENERATING A BROAD AREA OF CLUSTERS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF A LINE FROM 12N64W ALONG 17N72W TO 12N83W. A SURFACE TROUGH IS EMBEDDED IN THIS BROAD CYCLONIC WIND FIELD...EXTENDING FROM NEAR 15N76W INTO THE MONSOONAL GYRE NEAR 11N78W. THE MONSOON TROUGH EXTENDS ACROSS CENTRAL AMERICA ALONG COSTA RICA INTO NRN COLOMBIA. EXPECT THE SURFACE TROUGH TO COMPLETELY BECOME EMBEDDED IN THE MONSOON GYRE WITHIN THE NEXT 24-36 HOURS. ATLANTIC OCEAN... A WEAKENING SURFACE RIDGE IS ACROSS THE WRN ATLC WATERS PROVIDING FAIR WEATHER CONDITIONS TO MOST OF THIS REGION...AS AN UPPER LEVEL SHORTWAVE/TROUGH MOVES OFF THE ERN CONUS SEABOARD THIS AFTERNOON. PRE-FRONTAL SHOWERS ARE ALREADY SHOWING UP ON DOPPLER RADAR IMAGERY MOVING ACROSS THE FLORIDA PENINSULA INTO THE ATLC WATERS N OF 27N. FAR AHEAD ACROSS THE CENTRAL ATLC...A BROAD UPPER TROUGH/OCCLUDED LOW MOVES ACROSS THIS REGION REFLECTING A 1008 MB LOW CENTERED NEAR 32N37W. THIS LOW PRESSURE SYSTEM IS MOVING NE OUT OF OUR DISCUSSION AREA. A COLD FRONT EXTENDS S FROM THE OCCLUSION POINT N OF THE LOW INTO OUR AREA ALONG 32N36W AND CONTINUES SW ALONG 25N38W TO 21N43W... BECOMING A SURFACE TROUGH TO NEAR 17N48W. SCATTERED SHOWERS ARE WITHIN 150 NM AHEAD OF THE FRONT N OF 20N. A RECENT ASCAT PASS OVER THIS SYSTEM REVEALED NEAR GALE FORCE WINDS WITHIN 270 NM SE AND 150 NM NW QUADRANT GENERATING SEAS 8 TO 13 FT. A SHARP UPPER RIDGE COVERS THE ERN N ATLC WITH SURFACE RIDGING AXIS EXTENDING INTO OUR REGION ALONG 32N21W TO 15N32W...KEEPING FAIR WEATHER CONDITIONS ELSEWHERE E OF 30W. EXPECT THE COLD FRONT CURRENTLY IN THE GULF OF MEXICO TO COMPLETELY MOVE INTO THE WRN ATLC WITH CONVECTION IN 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA