000 AXNT20 KNHC 270011 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED DEC 26 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC ...THE ITCZ... ITCZ AXIS RUNS ALONG 6N11W 2N24W 1N40W EQUATOR AT 44W... INTO NE BRAZIL. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM NORTH OF THE AXIS BETWEEN 11-25W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NMI NORTH OF THE AXIS BETWEEN 25-46W. ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT WITH A LINE OF VIGOROUS THUNDERSTORMS EXTENDS FROM THE LOUISIANA COAST SOUTHWESTWARD INTO THE GULF. THE STRONGEST CONVECTION IS NORTH OF 25N. THE FRONT CONNECTS TO A 1006 MB SURFACE LOW OVER THE TEXAS-LOUISIANA BORDER. SOUTH TO SOUTHEASTERLY FLOW OF UP TO 30 KT IS SEEN AHEAD OF THE FRONT WITH NORTH TO NORTHWESTERLIES UP TO 20 KT IN THE EXTREME NORTHWESTERN GULF. A SURFACE HIGH OF 1019 MB IS OBSERVED OVER THE FLORIDA PANHANDLE. IN THE UPPER TROPOSPHERE WINDS PEAK NEAR 120 KT IN THE WEST-SOUTHWESTERLY FLOW OF THE JET...WHICH IS CENTERED NEAR LOUISIANA. DESPITE THE CURRENT APPEARANCE OF THE FRONT AND ASSOCIATED CONVECTION...THE COLD AIR ADVECTION BEHIND THE FRONT SHOULD SLACKEN OVER THE NEXT 24 HOURS AND BE REPLACED BY SOUTHERLY RETURN FLOW AHEAD OF THE NEXT STORM SYSTEM. THE CARIBBEAN SEA... THE CARIBBEAN REMAINS TYPICALLY TRANQUIL FOR THIS TIME OF YEAR WITH NO AREAS OF ORGANIZED CONVECTION PRESENT. A MODERATELY ENHANCED PRESSURE GRADIENT BETWEEN THE 1008 MB LOW IN THE EXTREME SW CARIBBEAN AND HIGH PRESSURE CENTERED EAST OF BERMUDA IS PRODUCING EASTERLY TRADEWINDS OF UP TO 25 KT...BUT GENERALLY WEAKER. IN THE UPPER LEVELS...HIGH PRESSURE IS CENTERED SOUTH OF HISPANIOLA AND IS CAUSING THE STRONG SUBSIDENCE SEEN THROUGHOUT THE CARIBBEAN. THE ATLANTIC OCEAN... AN OCCLUDING LOW IS AT 28N41W WITH AN ASSOCIATED FRONTAL BOUNDARY EXTENDING EAST AND SOUTH OF ITS CENTER. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 90 NMI OF THE FRONTAL BOUNDARY...WHICH EXTENDS TO ABOUT 20N. THIS LOW SHOULD CONTINUE MEANDERING NEAR 30N40W DURING THE NEXT FEW DAYS. ADDITIONAL WIDESPREAD MODERATE CONVECTION IS OBSERVED BETWEEN 13N TO 20N AND 25W TO 36W...MAINLY BEING FORCED BY A STRONG JET ALOFT. HIGH PRESSURE DOMINATES MOST OF THE SUBTROPICAL NORTH ATLANTIC WITH A 1025 MB HIGH CENTERED AT 31N56W. FARTHER TO THE WEST...A FRONTAL BOUNDARY EXTENDS FROM NEAR SOUTH FLORIDA UP TO 31N75W CONNECTING TO A DEVELOPING CYCLONE NEAR CAPE HATTERAS. A WEAK SURFACE TROUGH ALSO WAS ANALYZED JUST EAST OF SOUTHERNMOST FLORIDA...THOUGH THE FEATURE IS MERGING WITH THE FRONTAL BOUNDARY. THE FRONTAL BOUNDARY SHOULD LIKELY WEAKEN OVER THE NEXT DAY AS IS MOVES SLOWLY EASTWARD. $$ CWL