000 AXNT20 KNHC 081138 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST THU DEC 07 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA... CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA... NORTHEASTERN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 4N10W 3N20W 4N30W 4N40W 3N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS SEEN WITHIN 30 NM ON EITHER SIDE OF THE AXIS BETWEEN 38W-43W AND BETWEEN 46W-48W. ...DISCUSSION... THE GULF OF MEXICO... WLY UPPER LEVEL FLOW IS CARRYING ABUNDANT MOISTURE AND HIGH CLOUDS E ACROSS MUCH OF THE GULF EARLY THIS MORNING. SATELLITE DERIVED WINDS INDICATED CORE SPEEDS OF 60-80 KT OVER THE AREA. A DEEP LAYER TROUGH IS AMPLIFYING ACROSS THE EASTERN U.S. AND THE NORTHERN GULF WATERS. AS OF 0900 UTC...THE ATTENDANT COLD FRONT EXTENDS ACROSS WESTERN CUBA AND THE YUCATAN PENINSULA INTO THE BAY OF CAMPECHE. A LINE OF SHOWERS WITH EMBEDDED TSTMS IS JUST SE OF THE FLORIDA KEYS AND SE FLORIDA ASSOCIATED WITH THE FRONT. THIS FRONTAL BOUNDARY IS GENERALLY AT THE LEADING EDGE OF A STRONG 1042 MB SFC HIGH BUILDING INTO THE NRN GULF FROM KANSAS. STRONG N-NE WINDS ARE BLOWING BEHIND THE FRONT. EARLIER QUIKSCAT PASS INDICATED WIND SPEEDS OF 25 TO 35 KT. A GALE WARNING IS IN EFFECT FOR THE WRN GULF FROM 22N TO 25N W OF 94W AND FROM 25N TO 28N W OF 90W...WITH RAPIDLY INCREASING NE WINDS AND WIND WAVES. THESE CONDITIONS WILL GRADUALLY SUBSIDE THROUGH THE WEEKEND AS THE HIGH WEAKENS AND SHIFTS E. BASED ON SFC DATA AND THE QUIKSCAT PASS...THE SFC TROUGH THAT WAS PREVIOUSLY ALONG THE WESTERN GULF WAS REMOVED FROM THE 06Z SFC CHART. THE BROWNSVILLE DOPPLER RADAR IS STILL SHOWING PATCHES OF LIGHT RAIN IN THE AREA...AFFECTING THE DEEP SOUTH AND NE MEXICO...INCLUDING THE CITIES OF MONTERREY...SALTILLO AND MONCLOVA. NIGHT CHANNEL VIS IMAGES SHOW COLD STRATOCUMULUS CLOUDS OVER THE GULF. THE GFS MODEL SUGGESTS THAT MOST OF THE PRECIP WILL BE CONFINED TO THE WRN GULF/COASTAL MEXICO INCLUDING THE BAY OF CAMPECHE FRI THROUGH SATURDAY. CARIBBEAN SEA... DRY MID TO UPPER AIR CONTINUES TO DOMINATE MUCH OF THE CARIBBEAN SEA EARLY THIS MORNING. A SHORT WAVE TROUGH REMAINS ALONG 79W/80W. A SFC TROUGH HAS DEVELOPED OVER THE SAME AREA GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS. COMPUTER MODEL SUGGESTS THAT THIS SHOWER ACTIVITY WILL MOVE WWD TOWARD NICARAGUA AND HONDURAS DURING THE NEXT 12-24 HOURS. AN UPPER RIDGE EXTENDS FROM THE SW PORTION OF THE BASIN THROUGH HISPANIOLA INTO THE W-CENTRAL ATLC. A WEAKENING UPPER TROUGH ENTERS THE EASTERN CARIBBEAN NEAR GUADELOUPE FROM THE TROPICAL NORTH ATLC. THE TRADE WINDS ARE CARRYING PATCHES OF LOW LEVEL MOISTURE WITH LIGHT SHOWERS ACROSS THE BASIN. ONE OF THEM IS APPROACHING THE ABC ISLANDS. A DIFFLUENT PATTERN ALOFT IS SUPPORTING THE DEVELOPMENT OF SMALL AREA OF SHOWERS/ISOLATED TSTMS OVER THE GULF OF HONDURAS AND IS ALSO ENHANCING THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE SFC TROUGH. THE QUIKSCAT PASS SHOWED THE TRADES IN THE 15 TO 25 KT RANGE...WITH THE STRONGEST WINDS OFF THE COLOMBIAN COAST. THE STRONG COLD FRONT MENTIONED ABOVE IS ENTERING THE NW CARIBBEAN. NE FLOW ARE EXPECTED TO INCREASE OVER THE NW PORTION OF THE CARIBBEAN FRI EVENING INTO SAT AS STRONGER HIGH PRESSURE BUILDS N OF THE AREA. THE ATLANTIC OCEAN... A COLD FRONT IS MOVING ACROSS THE SW NORTH ATLC AND THE NORTHERN BAHAMAS. STRONG HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE FRONT FRIDAY AND SATURDAY...ALLOWING NE WINDS AND WIND WAVES TO INCREASE. A GALE WARNING IS ALREADY IN EFFECT BEHIND THE FRONT W OF 75W. A PRE-FRONTAL TROUGH RUNS FROM 31N70W TO 23N73W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS AHEAD OF THE TROUGH FROM 25N-31N BETWEEN 64W-68W. DIFFLUENCE BETWEEN THE DEEP LAYERED TROUGH OVER THE ERN U.S. AND THE UPPER RIDGE EXTENDING NE THROUGH HISPANIOLA INTO THE W-CENTRAL ATLC IS ENHANCING THIS CONVECTIVE ACTIVITY. A PRONOUNCED UPPER LOW IS SEEN SPINNING NEAR 19N36W. ABUNDANT UPPER LEVEL MOISTURE IS ON THE SE SEMICIRCLE OF THIS FEATURE...WITH SCATTERED SHOWERS POSSIBLE FROM 13N-22N EAST OF 30W. A STRONG 1038 MB SFC HIGH PRES LOCATED NORTH OF THE AREA DOMINATES THE E AND CENTRAL ATLC. PATCHES OF LOW LEVEL MOISTURE ARE SEEN UNDER THE INFLUENCE OF THIS SYSTEM OVER THE OCEAN. WLY JET OVER THE DEEP TROPICS CONTINUES TO SHEAR THE CONVECTION OVER THE ITCZ TO THE E. $$ GR