000 AXNT20 KNHC 090550 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT DEC 09 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 5N30W 4N40W 4N54W. SCATTERED MODERATE/ISOLATED CONVECTION IS FROM 3N-6N BETWEEN 37W-47W. CLUSTERS OF SIMILAR CONVECTION ARE SEEN FROM 2N-7N BETWEEN 50W-55W. ...DISCUSSION... THE GULF OF MEXICO... A SHORT WAVE TROUGH IS OVER NE MEXICO. NEARLY ZONAL UPPER LEVEL FLOW DOMINATES THE GULF. THESE WINDS ARE CARRYING ABUNDANT MOISTURE AND HIGH CLOUDS E ACROSS MUCH OF THE GULF AND SOUTHERN FLORIDA. AT THE SURFACE...STRONG HIGH PRESSURE COVERS THE SE U.S. AND THE GULF...INCLUDING ALSO THE FLORIDA PENINSULA. THIS IS PRODUCING WIDESPREAD 20 TO 25 KT NE FLOW ACROSS THE GULF... WITH WINDS NEAR GALE FORCE IN THE SW PORTION. A SFC TROUGH IS OVER THE FAR W GULF ALONG 25N96W 18N93W. THE BROWNSVILLE DOPPLER RADAR SHOWS THAT NUMEROUS SHOWERS AND ISOLATED TSTMS ARE ASSOCIATED WITH THE NORTHERN END OF THIS TROUGH. HIGH PRES WILL SHIFT E TODAY WITH DIMINISHING WINDS AND SEAS OVER THE W GULF. STRONG NE TO E WINDS WILL REMAIN OVER THE SE GULF AND THE STRAITS OF FLORIDA DURING THE WEEKEND. CARIBBEAN SEA... WLY UPPER LEVEL FLOW ALSO DOMINATES THE NW QUADRANT OF THE CARIBBEAN SEA AND CUBA. A RIDGE EXTENDS FROM NORTHERN COLOMBIA THROUGH THE ABC ISLANDS/E CARIBBEAN TO THE LEEWARD ISLANDS INTO THE CENTRAL ATLC. DRY AIR ALOFT/SUBSIDENCE COVERS THE E CARIBBEAN WITH ONLY PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADE WINDS. THE TAIL END OF A FRONTAL BOUNDARY CROSSES EASTERN CUBA AND THE NW CARIBBEAN TO NEAR 16N86W IN THE GULF OF HONDURAS. SCATTERED SHOWERS ARE RELATED TO THE FRONT. EARLIER QUIKSCAT PASS INDICATED NE WINDS IN THE 20-25 KT RANGE BEHIND THE FRONT OVER THE YUCATAN CHANNEL AND THE NW CARIBBEAN. A SFC TROUGH REMAINS ALONG 80W/81W FROM 10N-17N. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS BETWEEN THE TROUGH AND THE COASTLINE OF NICARAGUA. THIS FEATURE WILL MOVE EWD INTO CENTRAL AMERICA GENERATING ISOLATED TO SCATTERED CONVECTION OVER THE AREA. MODEL GUIDANCE SUGGESTS THE WRN CARIBBEAN WILL CONTINUE TO SEE SCATTERED SHOWERS/TSTMS THROUGH THE WEEKEND...WITH SPEED CONVERGENCE AND THE OLD FRONTAL BOUNDARY MEANDERING. HIGH PRES N OF THE AREA WILL MAINTAIN MODERATE TO FRESH ELY WINDS THROUGH THE WEEKEND. THE ATLANTIC OCEAN... STRONG SFC HIGH PRESSURE IS BUILDING INTO THE SW NORTH ATLC OFF THE FLORIDA COAST TONIGHT...FROM A 1037 MB CENTER OVER ERN TENNESSEE. THIS IS PRODUCING FRESH TO STRONG NE WINDS OVER MUCH OF THE AREA N OF 24N AND W OF 65W...JUST BEHIND A COLD FRONT THAT ENTERS THE AREA NEAR 32N61W THEN CONTINUES SW ACROSS EASTERN CUBA AND THE NW CARIBBEAN. LARGE NE WIND WAVES AND SWELL TO SPREAD THROUGH THE SOUTH FLORIDA WATERS INTO SAT...SUBSIDING SLOWLY THROUGH EARLY NEXT WEEK. UPPER FLOW OVER THE SW NORTH ATLC IS MOSTLY SW AHEAD OF THE UPPER TROUGH OVER THE ERN SEABOARD. DIFFLUENCE BETWEEN THIS FEATURE AND AN UPPER RIDGE EXTENDING NE THROUGH THE LEEWARD ISLANDS INTO THE CENTRAL ATLC IS HELPING TO SUPPORT THE CONVECTIVE ACTIVITY ASSOCIATED WITH A PRE-FRONTAL TROUGH THAT LIES ALONG 30N60W 25N66W TO THE SOUTHERN BAHAMAS. AN UPPER TROUGH EXTENDS FROM THE E ATLC NEAR 32N30W SW TO NEAR 13N50W. AN UPPER RIDGE EXTENDS UP THE COAST OF W AFRICA...WHICH HAS ABUNDANT MID TO UPPER MOISTURE SPREADING AROUND ITSELF. WLY FLOW DOMINATES THE DEEP TROPICS SOUTH OF THE AFOREMENTIONED UPPER TROUGH. A 1041 MB SFC HIGH PRES OVER THE AZORES REMAINS IN CONTROL OF THE WEATHER PATTERN OVER THE E-CENTRAL ATLC PRODUCING MODERATE TO FRESH ELY WINDS. PATCHES OF LOW LEVEL MOISTURE WITH EMBEDDED SHOWERS ARE OBSERVED UNDER THE INFLUENCE OF THIS SYSTEM. $$ GR