000 AXNT20 KNHC 222346 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON DEC 22 2008 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... ITCZ IS CENTERED ALONG 6N10W 3N20W 2N40W 2N51W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 37W FROM 5N-13N. ISOLATED SHOWERS ARE ASSOCIATED WITH THE TROUGH BETWEEN 34W-40W. ISOLATED MODERATE CONVECTION IS FROM 1N-6N BETWEEN 17W-22W. ELSEWHERE... SCATTERED MODERATE CONVECTION IS WITHIN 150 NM OF THE SOUTH AMERICAN COAST BETWEEN 48W-61W. ...DISCUSSION... GULF OF MEXICO... AS OF 2100 UTC...A COLD FRONT EXTENDS FROM THE W ATLC THROUGH THE STRAITS OF FLORIDA TO 22N87W THEN CONTINUING STATIONARY INTO A 1019 MB SURFACE LOW LOCATED NEAR 24N96W. WITH A SURFACE RIDGE OF HIGH PRESSURE EXTENDING FROM SRN TEXAS SWD ALONG THE ERN COAST OF MEXICO...A STATIONARY FRONTAL BOUNDARY CONTINUES SWD FROM THE LOW INTO THE WRN BAY OF CAMPECHE AND INLAND ACROSS ERN MEXICO NEAR VERACRUZ. BROKEN/OVERCAST STRATOCUMULUS LOW CLOUDS WITH ISOLATED SHOWERS ARE N OF THE FRONT AND W OF 86W. A SURFACE TROUGH ALSO EXTENDS N-NW FROM THE SURFACE LOW ALONG THE TEXAS GULF COAST FROM BROWNSVILLE TO GALVESTON. SE OF THE FRONT... OVERCAST LOW TO MIDDLE LEVEL CLOUDINESS WITH EMBEDDED SHOWERS COVER THE BAY OF CAMPECHE S OF 21N. A DEEP LAYERED TROUGH OVER THE ERN CONUS AND N/CENTRAL GULF SUPPORTS THE AFOREMENTIONED FRONTAL BOUNDARY. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR ARE NOTED ACROSS SRN FLORIDA AND THE SRN GULF WATERS... MAINLY S OF THE SURFACE FRONTAL BOUNDARY. CARIBBEAN SEA... THE CARIBBEAN SEA REMAINS UNDER THE INFLUENCE OF A BROAD UPPER HIGH CENTERED NEAR 14N69W AND ENCOMPASSES THE ENTIRE CARIBBEAN BASIN WITH STRONG SUBSIDENCE IN DRY AIR. THIS UPPER-LEVEL FEATURE ALSO ENVELOPS CENTRAL AMERICA AND THE NW PORTION OF SOUTH AMERICA. HOWEVER...AREAS OF SHALLOW LOW-LEVEL MOISTURE STREAM ACROSS THE BASIN USHERED IN ON NE-E TRADE WIND FLOW. ISOLATED TO SCATTERED SHOWERS ARE NOTED MOVING ACROSS THE NRN LEEWARD ISLANDS N OF 15N...ALSO FROM 16N-19N BETWEEN 69W-76W IN THE N/CENTRAL CARIBBEAN...AND S OF 18N W OF 80W IN THE WRN CARIBBEAN. LOOKING AHEAD...STRONG HIGH PRESSURE IS FORECAST TO BUILD N OF AREA WITH INCREASING TRADE WINDS EXPECTED OVER THE TROPICAL N ATLC AND MUCH OF THE CARIBBEAN SEA WED THROUGH FRI. ATLANTIC OCEAN... A COLD FRONT ENTERS THE W ATLC NEAR 32N67W AND EXTENDS ACROSS THE NW BAHAMAS AND STRAITS OF FLORIDA INTO THE GULF OF MEXICO. BROKEN/OVERCAST STRATOCUMULUS LOW CLOUDS WITH ISOLATED SHOWERS ARE BEHIND THE FRONT. A BROAD UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN SEA WITH AXIS FROM THE MONA PASSAGE NE TO BEYOND 32N48W. MOSTLY FAIR WEATHER CONDITIONS ARE OBSERVED E OF THE COLD FRONT TO 50W. A SURFACE TROUGH IS IN THE CENTRAL ATLC AND EXTENDS FROM 28N42W TO 19N42W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 150 NM W OF THE TROUGH WHICH IS SUPPORTED BY UPPER LEVEL TROUGHING OVER THE E/CENTRAL ATLC. THE AXIS ENTERS THE AREA NEAR 32N21W THEN CONTINUES SW INTO THE TROPICS TO NEAR 15N40W AND THEN WWD TO NEAR 15N55W. UPPER DIFFLUENCE E OF THIS UPPER TROUGH ALONG WITH AN UPPER RIDGE AMPLIFIED ALONG THE W AFRICAN COAST IS ENHANCING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 200 NM ON EITHER SIDE OF A LINE FROM 28N10W TO 14N33W. NE TO E WINDS ARE EXPECTED TO INCREASE ACROSS THE TROPICS LATE MONDAY TO AT LEAST MIDWEEK AS STRONG HIGH PRESSURE BUILDS N OF AREA. $$ HUFFMAN