000 AXNT20 KNHC 130551 CCA TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT DEC 13 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 IS CENTERED ALONG 8N13W 4N30W 4N54W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 56W S OF 14W. CYCLONIC CURVATURE IS EVIDENT IN THE LOW CLOUDS ALONG THE TROUGH AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-6N BETWEEN 3W-8W. SIMILAR CONVECTION IS FROM 3N-9N BETWEEN 27W-36W. ...DISCUSSION... GULF OF MEXICO... A COOLER AND DRIER AIRMASS IS ACROSS THE GULF REGION IN THE WAKE OF A SURFACE COLD FRONT THAT EXTENDS FROM THE W ATLC ACROSS WRN CUBA TO THE NE TIP OF THE YUCATAN PENINSULA NEAR 22N88W. THE INCREASED SURFACE PRESSURE GRADIENT IN THE VICINITY OF THIS COLD FRONT IS SUPPORTING NORTHERLY SURFACE WINDS OF 20 TO 25 KT ACROSS PORTIONS OF THE E GULF. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS COVER THE SRN HALF OF THE GULF S OF 25N...INCLUDING THE ERN BAY OF CAMPECHE AND THE YUCATAN PENINSULA DUE TO THE COLD AIR ADVECTION OVER RELATIVELY WARM WATERS. MODERATE TO STRONG SUBSIDENCE IN STRONG W-NW FLOW ALOFT IS INHIBITING ANY DEEP CONVECTION ACROSS THE GULF REGION. A SURFACE RIDGE EXTENDS ACROSS THE WRN GULF...ANCHORED BY A 1028 MB SURFACE HIGH THAT DOMINATES MOST THE GULF. LOOKING AHEAD...EXPECT RETURN SOUTHERLY FLOW TO INCREASE ACROSS THE WRN GULF SAT THROUGH LATE SUN AS LOW PRESSURE DEVELOPS AND MOVES THROUGH THE CENTRAL U.S. PLAINS. CARIBBEAN SEA... A COLD FRONT OVER THE W ATLC ENTERS THE CARIBBEAN SEA THROUGH ERN CUBA THEN CONTINUES SOUTH AS A STATIONARY FRONT THROUGH 18N80W TO COSTA RICA NEAR 10N83W. SCATTERED SHOWERS ARE ALONG AND WITHIN 90 NM ON EITHER SIDE OF THIS FRONT. BEHIND THE FRONT...A COOLER AND DRIER AIRMASS IS ACROSS THE NW CARIBBEAN... WRN AND CENTRAL CUBA AND NRN CENTRAL AMERICA WHERE BROKEN TO OVERCAST CLOUDINESS WITH EMBEDDED LIGHT SHOWERS ARE OBSERVED. THE REMAINDER OF THE CARIBBEAN SEA REMAINS UNDER THE INFLUENCE OF A STRONG 1040 MB HIGH PRESSURE SYSTEM CENTERED W OF THE AZORES. PATCHES OF LOW LEVEL MOISTURE USHERED IN ON MODERATE TO FRESH TRADE WINDS CONTINUE TO MOVE WWD ON THE SW PERIPHERY OF THE SURFACE HIGH. SATELLITE IMAGERY REVEALS LARGEST AREA OF LOW TOPPED SHOWERS S OF JAMAICA FROM 13N-16N BETWEEN 71W-80W MOVING W-SW E OF THE STATIONARY FRONT. ALOFT...A RIDGE EXTENDS FROM N COLOMBIA ACROSS CENTRAL AMERICA TO SE MEXICO. ATLANTIC OCEAN... A DEEP LAYERED TROUGH OVER THE ERN CONUS SUPPORTS A PAIR OF COLD FRONTS OVER THE W ATLC. THE MAIN FRONT ENTERS THE FORECAST AREA NEAR 32N70W AND CONTINUES SW OVER THE CENTRAL BAHAMAS TO ERN CUBA NEAR 21N77W. THE SECONDARY FRONT EXTENDS FROM 31N75W ACROSS THE NW BAHAMAS AND INTO THE STRAITS OF FLORIDA AND SE GULF OF MEXICO. A PRE-FRONTAL TROUGH WITH A BAND OF SCATTERED SHOWERS AND ISOLATED TSTMS IS WITHIN 150 NM E OF THE MAIN BOUNDARY N OF 26N. THE REMAINDER OF THE ATLC IS UNDER THE INFLUENCE OF A STRONG 1039 MB SURFACE HIGH CENTERED E OF THE AZORES NEAR 37N38W. SUBSIDENCE AROUND THIS HIGH IS GENERALLY SUPPORTING FAIR WEATHER CONDITIONS ACROSS MUCH OF THE ERN ATLC. HOWEVER...AN UPPER-LEVEL TROUGH WITH AXIS ALONG 32N56W TO 17N48W IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 22N-27N BETWEEN 45W-53W. THIS SURFACE HIGH IS ALSO GENERATING A WIDE SWATH OF MODERATE TO STRONG ELY WINDS ACROSS THE BASIN PARTICULARLY FROM 21N-29N E OF 50W. BY EARLY NEXT WEEK...COMPUTER MODELS ARE ANTICIPATING THE DEVELOPMENT OF A LOW PRESSURE SYSTEM OVER THE TROPICAL CENTRAL ATLC AS THE UPPER LEVEL DEEP LAYERED TROUGH CURRENTLY OVER THE ERN CONUS MOVES EWD. $$ HUFFMAN