000 AXNT20 KNHC 262347 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON DEC 26 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 MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 06N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N14W TO 05N23W TO 02N33W TO 01N50W. ISOLATED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 22W-28W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING EASTWARD OVER NORTH TEXAS THIS EVENING WITH THE MID-LEVEL TROUGH AXIS EXTENDING FROM 32N98W TO 26N100W. THE TROUGH SUPPORTS A 1019 MB LOW CENTERED ALONG THE LOUISIANA COAST NEAR 29N91W AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW TO 23N93W WHERE IT BECOMES STATIONARY TO THE SOUTHERN MEXICO COAST NEAR 18N94W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. IN ADDITION...A STATIONARY FRONT MEANDERS EAST FROM THE LOW TO THE FLORIDA PENINSULA ALONG 29N AND IS PROVIDING A SURFACE FORCING MECHANISM TO GENERATE WIDELY SCATTERED SHOWERS N OF 27N TO THE GULF COAST...AND SCATTERED SHOWERS INLAND OVER PORTIONS OF THE GULF COASTAL PLAINS AND SOUTHERN MISSISSIPPI RIVER VALLEY THIS EVENING. WEST OF THE FRONT...STRONG N-NW WINDS IN THE RANGE OF 15 TO 25 KT ARE FORECAST TO CONTINUE THROUGH THE OVERNIGHT HOURS AS HIGH PRESSURE ANCHORED OVER NORTHERN MEXICO AND TEXAS BUILDS IN ACROSS THE WESTERN AND CENTRAL GULF THROUGH LATE TUESDAY INTO WEDNESDAY. CARIBBEAN SEA... AN UPPER LEVEL RIDGE EXTENDS ACROSS THE CARIBBEAN SEA WITH AXIS FROM NORTHERN VENEZUELA NEAR 08N66W NW TO EASTERN CUBA NEAR 21N78W. WATER VAPOR IMAGERY INDICATES DRY AIR AND SUBSIDENCE OVER MUCH OF THE BASIN WITH THE EXCEPTION OF SOME MIDDLE TO UPPER LEVEL MOISTURE OVER THE WESTERN CARIBBEAN IN THE VICINITY OF 17N80W. OTHERWISE...FRESH TO STRONG E-NE TRADES CONTINUE ACROSS MUCH OF THE BASIN THIS EVENING WITH GENERALLY FAIR SKIES. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH TUESDAY. ALSO...LOW-LEVEL CONVERGENCE OF THE TRADES ACROSS THE WESTERN CARIBBEAN IS GENERATING A FEW POSSIBLE ISOLATED SHOWERS FROM 13N-16N BETWEEN 77W-83W...AND FROM 13N-20N BETWEEN 83W-88W... WHICH INCLUDES PORTIONS OF NORTHERN NICARAGUA...AND HONDURAS. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY THIS EVENING LOCATED NORTH OF THE DISCUSSION AREA WITH AXIS FROM 38N63W TO 32N68W THAT SUPPORTS A COLD FRONT ANALYZED FROM BERMUDA NEAR 32N65W SW ALONG 30N69W TO 28N75W TO THE FLORIDA PENINSULA NEAR 28N80W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. EARLIER MORNING ASCAT PASSES DEPICTED STRONGER NORTHERLY WINDS NORTH OF THE FRONT EAST OF 72W. FARTHER EAST...A WEAKENING FRONTAL TROUGH EXTENDS INTO THE CENTRAL ATLC WITH A COLD FRONT ANALYZED FROM 32N45W TO 28N52W AND A DISSIPATING STATIONARY FRONT TO 26N61W. LOW-LEVEL MOISTURE REMAINS LIMITED AS THE ENTIRE FRONT CONTINUES TO LOSE MIDDLE TO UPPER LEVEL SUPPORT WITH AN UPPER LEVEL RIDGE AXIS ALONG 50W AND INFLUENCE LOCATED BETWEEN 42W AND 58W. A WEAK SURFACE TROUGH IS ANALYZED TO THE SE OF THE FRONT FROM 32N40W TO 30N43W TO 23N49W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF AN UPPER LEVEL LOW CENTERED NEAR 19N36W AND THE ASSOCIATED TROUGH AXIS EXTENDING FROM 26N33W TO 13N40W. A SIGNIFICANT AMOUNT OF MOISTURE AND POSSIBLE SCATTERED SHOWERS AND ISOLATED TSTMS SUPPORTED BY STRONG MIDDLE TO UPPER LEVEL DIFFLUENCE ARE LOCATED EAST OF THE TROUGH AXIS FROM 08N-24N BETWEEN 16W-32W. THE REMAINDER OF THE EASTERN ATLC N OF 24N IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM 37N18W TO 25N33W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN