000 AXNT20 KNHC 232344 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI DEC 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N12W TO 05N27W TO 06N39W TO 04N51W. SCATTERED MODERATE CONVECTION IS FROM 03N-07N BETWEEN 17W-27W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY UPPER LEVEL FLOW IS NOTED ACROSS THE ENTIRE GULF THIS EVENING ON THE NORTHWESTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 24N86W. THIS UPPER LEVEL HIGH IS A PORTION OF A BROADER RIDGE THAT EXTENDS FROM THE SW NORTH ATLC NEAR 25N66W TO THE SE GULF...THEN SW TO 18N98W OVER INTERIOR MEXICO. WHILE UPPER LEVEL SHORTWAVE ENERGY HAS PROGRESSED TO THE NE OF THE BASIN OVER THE PAST 24 HOURS...A STALLED FRONTAL BOUNDARY REMAINS ANALYZED FROM THE BIG BEND REGION OF FLORIDA NEAR 30N84W TO 26N90W WHERE IT BECOMES STATIONARY ALONG 23N95W TO 19N95W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT E OF 90W AND FROM 23N-27N BETWEEN 87W-90W. NORTH AND WEST OF THE FRONTAL BOUNDARY...N TO NE WINDS IN THE RANGE OF 15 TO 25 KT ARE NOTED ON RECENT SHIP...BUOY...AND OFFSHORE OIL PLATFORMS AS WELL AS A RECENT ASCAT PASS AROUND 23/1636 UTC. WATER VAPOR IMAGERY INDICATES A STRONG UPPER LEVEL LOW AND ASSOCIATED TROUGH ACROSS THE SW CONUS AND NW MEXICO WHICH IS EXPECTED TO REINFORCE THE NORTHERLY WINDS LATE SATURDAY THROUGH SUNDAY AND BEGIN TO PROGRESS THE FRONT EASTWARD ONCE AGAIN. CARIBBEAN SEA... AN UPPER LEVEL RIDGE EXTENDS ACROSS THE CARIBBEAN SEA WITH AXIS FROM THE SE CARIBBEAN NEAR 11N63W NW TO THE YUCATAN CHANNEL NEAR 21N85W. WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE IS PRESENT OVER MUCH OF THE BASIN THIS EVENING IN THE MIDDLE AND UPPER LEVELS. HOWEVER...AT THE SURFACE A STRONG PRESSURE GRADIENT REMAINS ACROSS THE CENTRAL CARIBBEAN AS A 1026 MB HIGH IS CENTERED IN THE SW NORTH ATLC NEAR 31N59W AND LOWER PRESSURE LOCATED OVER NORTHERN SOUTH AMERICA. AS A RESULT... EAST-NORTHEAST TRADES REMAIN STRONG IN THE RANGE OF 20 TO 30 KT AS DEPICTED BY AN EARLIER ASCAT PASS AROUND 23/1458 UTC. ELSEWHERE...MOST LOW-LEVEL MOISTURE IS LOCATED ALONG THE CENTRAL AMERICA COAST WITH CONVERGENCE OF THE TRADES GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WEST OF A LINE FROM 09N80W TO 18N84W TO 19N88W. THE SURFACE HIGH OVER THE SW NORTH ATLC IS FORECAST TO CONTINUE A GRADUAL WEAKENING TREND OVER THE NEXT 24-36 HOURS WITH FRESH TO STRONG E-NE TRADES EXPECTED TO PERSIST BETWEEN 65W-80W THROUGH TUESDAY. ATLANTIC OCEAN... SURFACE RIDGING AROUND A 1026 MB HIGH CENTERED NEAR 31N59W IS PROVIDING MOSTLY FAIR WEATHER ACROSS THE SW NORTH ATLC THIS EVENING. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 25N66W. AN APPROACHING COLD FRONT ANALYZED ALONG THE COAST FROM 34N79W TO 31N82W WILL CONTINUE TO PROVIDE ISOLATED SHOWERS NW OF A LINE FROM 30N81W TO 32N77W. FARTHER EAST...AN UPPER LEVEL LOW CENTERED NEAR 25N44W AND ASSOCIATED TROUGHING WITH AXIS ALONG 43W SUPPORTS A SURFACE TROUGH ANALYZED INTO THE DISCUSSION AREA NEAR 32N42W TO 27N44W TO 21N43W. LOW-LEVEL CONVERGENCE EAST OF THE SURFACE TROUGH AXIS AND MIDDLE TO UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL TROUGH AXIS IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE AREA N OF 20N BETWEEN 35W-43W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1039 MB HIGH CENTERED NE OF THE AZORES NEAR 44N19W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN