000 AXNT20 KNHC 022358 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE DEC 02 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... THE ITCZ AXIS IS ANALYZED ALONG 8N12W 6N25W 8N40W INTO THE GUYANAS NEAR 3N54W. SCATTERED MODERATE CONVECTION IS FROM 7N-10N BETWEEN 29W-37W. SIMILAR CONVECTION IS NEAR 8N21W AND NEAR 6N45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER THE GUYANAS PARTICULARLY OVER THE NORTHERN PART. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYERED TROUGH EXTENDS ACROSS THE SE CONUS AND THE FLORIDA PANHANDLE TOWARD THE SW GULF OF MEXICO. THIS TROUGH SUPPORTS A SECONDARY/REINFORCING COLD FRONT THAT IS CURRENTLY SE OF THE AREA OVER WESTERN CUBA AND THE YUCATAN PENINSULA. MIDDLE TO UPPER LEVEL DRY AIR AND STRONG SUBSIDENCE IS OVER THE ENTIRE GULF REGION. BEHIND THE FRONT...A 1026 MB HIGH LOCATED NEAR 28N87W DOMINATES THE SE CONUS AND MOST OF THE AREA. SCATTERED COLD AIR STRATOCUMULUS CLOUDS ARE EVIDENT ON SATELLITE IMAGERY MAINLY OVER THE EASTERN HALF OF THE GULF AND THE SW PORTION. SOUTHERLY RETURN FLOW HAS BEEN ESTABLISHED OVER THE NW QUADRANT OF THE GULF IN ADVANCE OF THE NEXT COLD FRONT FORECAST TO MOVE OFFSHORE THE TEXAS COAST ON WED NIGHT. THE COMBINATION OF COLD AIR ADVECTION AND RESULTANT CLEAR SKIES WILL ALLOW TEMPERATURES TO DROP INTO THE LOWER/MID 50S IN SOUTH FLORIDA TONIGHT...WITH WIND CHILL VALUES LIKELY FALLING INTO THE 45-50F RANGE. CARIBBEAN SEA... A STATIONARY FRONT EXTENDS ACROSS EASTERN CUBA AND THE CARIBBEAN SEA CROSSING BETWEEN THE CAYMAN ISLANDS AND JAMAICA TO NEAR 12N83W. A BAND OF MAINLY LOW/MID CLOUDS WITHIN 90 NM EITHER SIDE OF THE FRONT CONTAINS EMBEDDED SHOWERS AND POSSIBLE WEAK ISOLATED TSTMS. BEHIND THE COLD FRONT...NLY WINDS IN THE 20-25 KT RANGE ARE TRANSPORTING ABUNDANT LOW LEVEL MOISTURE WITH MAINLY LIGHT SHOWERS ACROSS BELIZE...GUATEMALA AND HONDURAS. A SECONDARY FRONT IS MOVING ACROSS WESTERN CUBA AND THE YUCATAN PENINSULA REINFORCING THE PRESENT RATHER DRY AND COLD WEATHER CONDITIONS FOR THIS TIME OF THE YEAR ACROSS THE AREA PARTICULARLY THE MAJORITY OF THE ISLAND OF CUBA. A SURFACE TROUGH IS LOCATED IN THE ERN CARIBBEAN ALONG 68W/69W SOUTH OF 17N. THIS TROUGH SHOWS SOME TROPICAL-WAVE LIKE CHARACTERISTICS AND WILL CONTINUE TO MOVE WWD ACROSS THE CENTRAL CARIBBEAN ON WED REACHING THE ATLANTIC COAST OF NICARAGUA PROBABLY LATE THU. THE TROUGH IS CURRENTLY GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE ABC ISLANDS. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL RIDGE ANCHORED ON A HIGH N OF PUERTO RICO. THE RIDGE AXIS EXTENDS INTO THE E-CENTRAL CARIBBEAN THROUGH THE MONA PASSAGE. TYPICAL PATCHES OF LOW LEVEL MOISTURE ARE NOTED ACROSS THE LEEWARD ISLANDS AND PUERTO RICO USHERED IN ON E-NE 15-20 KT TRADES. IN THE UPPER LEVELS...STRONG SWLY WINDS AHEAD OF THE DEEP LAYERED TROUGH OVER THE GULF OF MEXICO ARE SEEN OVER NORTH CENTRAL AMERICA...THE NW CARIBBEAN AND CUBA. ATLANTIC OCEAN... TWO FRONTAL BOUNDARIES ARE ACROSS THE W ATLC WEST OF 70W. THE FIRST ONE IS A STATIONARY FRONT THAT ENTERS THE AREA NEAR 31N70W THEN CONTINUES SW ACROSS THE CENTRAL BAHAMAS AND EASTERN CUBA INTO THE CARIBBEAN SEA. THE SECOND ONE IS A REINFORCING COLD FRONT WHICH EXTENDS FROM A WEAK 1016 MB SFC LOW LOCATED NEAR 33N74W TO WESTERN CUBA AND THE YUCATAN PENINSULA. THE AFOREMENTIONED DEEP LAYERED TROUGH SUPPORTS THESE FRONTS. UPPER LEVEL SWLY WIND FLOW BETWEEN THIS UPPER-LEVEL TROUGH AND AN UPPER-LEVEL RIDGE CENTERED NEAR 25N62W IS HELPING TO INDUCE SCATTERED SHOWERS AND ISOLATED TSTMS ALONG THE FRONTS. TO THE E...A 1028 MB SURFACE HIGH LOCATED N OF THE AREA EXTENDS A RIDGE OVER THE CENTRAL AND W ATLC ROUGHLY BETWEEN 50W-70W. ACROSS THE E-CENTRAL ATLC...A 1011 MB SURFACE LOW IS CENTERED NEAR 28N41W. A SURFACE TROUGH ENTERS THE AREA NEAR 31N31W THEN CONTINUES SW ALONG 20N34W TO 11N46W. THIS SURFACE FEATURE IS SUPPORTED BY SHARP UPPER LEVEL TROUGHING THAT RUNS FROM AN UPPER LOW SITUATED NEAR 28N38W ACROSS THE DEEP TROPICS TO NEAR TRINIDAD AND TOBAGO ISLANDS. THE REMAINDER OF THE ATLANTIC OCEAN IS UNDER THE INFLUENCE OF A BROAD RIDGE CENTERED OVER SIERRA LEONE. UPPER DIFFLUENCE BETWEEN THESE TWO UPPER-LEVEL FEATURES IS SUPPORTING SCATTERED SHOWERS ALONG AND AHEAD OF THE ABOVE MENTIONED SFC TROUGH. $$ GR