000 AXNT20 KNHC 082343 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI DEC 08 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2330 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 4N30W 4N50W. SCATTERED MODERATE CONVECTION IS FROM 2N-6N BETWEEN 35W-42W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION SEEN FROM 1N-7N BETWEEN 45W-60W...WHICH INCLUDES THE NE SOUTH AMERICA. ...DISCUSSION... THE GULF OF MEXICO... STRONG HIGH PRESSURE HAS TAKEN OVER THE GULF SFC PATTERN...FROM A 1042 MB CENTER OVER ERN ARKANSAS. THIS IS PRODUCING WIDESPREAD 20 TO 25 KT NE FLOW ACROSS THE GULF...WITH WINDS TO GALE FORCE IN THE SW PORTION S OF 25N AND W OF 94W. A SFC TROUGH IS IN THE FAR W/SW GULF AS THE SYNOPTIC NE FLOW COLLIDES WITH THE MORE N TO NW FLOW SLIDING DOWN THE SLOPES OF THE SIERRA MADRES. THE TROUGH AT 2100 UTC WAS ANALYZED ALONG 26N97W 20N93W. NUMEROUS LIGHT TO MODERATE RAIN SHOWERS ANTICIPATED WITHIN 100 NM OF THIS FEATURE. EXTENSIVE MID TO UPPER MOISTURE IS ALSO SPREADING ACROSS MUCH OF THE GULF THIS EVENING...CARRIED BY ZONAL UPPER FLOW IN ADVANCE OF THE UPPER LOW SPINNING OVER NRN MEXICO. WINDS AND SEAS WILL SUBSIDE STEADILY AS WE MOVE THROUGH THE WEEKEND...ASIDE FROM THE FLORIDA STRAITS...WITH HIGH PRESSURE SLOWLY WEAKENING AND MOVING E TO NE. A MODERATE E SWELL WILL ALSO LINGER ACROSS TEXAS AND NE MEXICO BEACHES INTO EARLY NEXT WEEK FROM THE FETCH S OF THE HIGH. CARIBBEAN SEA... THE ONLY SIGNIFICANT WEATHER IN THE CARIBBEAN THIS EVENING IS ACROSS THE WRN PORTION...WHERE CLUSTERS OF SCATTERED MODERATE CONVECTION DOT THE AREA FROM 9N-19N BETWEEN 79W-84W. THIS SEEMS MOSTLY ASSOCIATED WITH SPEED CONVERGENCE DOWNSTREAM FROM THE SWATH OF 15 TO 25 KT TRADES IN THE CENTRAL CARIBBEAN...THOUGH WEAK SFC TROUGHING IN THE VICINITY IN ADDITION TO THE APPROACHING FRONT MAY ALSO BE PROVIDING SOME TRIGGER. THE CLOUD TOPS OVER THE CONVECTION ARE GETTING SHEARED TO THE E WITH UPPER WLY FLOW OVER THE AREA. AS OF 2100 UTC...THE COLD FRONT EXTENDS THROUGH THE NW CARIBBEAN FROM CENTRAL CUBA TO 16N85W IN THE GULF OF HONDURAS. NE FLOW EXPECTED TO INCREASE IN THE NW CARIB BEHIND THE FRONT TONIGHT AND SAT...AS STRONG HIGH PRESSURE BUILDS FROM THE N. 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. THE ATLANTIC OCEAN... STRONG SFC HIGH PRESSURE IS BUILDING INTO THE SW NORTH ATLC OFF THE FLORIDA COAST THIS EVENING...FROM A 1042 MB CENTER OVER ERN ARKANSAS. THIS IS PRODUCING FRESH TO STRONG NE WINDS OVER MUCH OF THE AREA N OF 24N AND W OF 65W...WHICH IS THE AREA BEHIND THE COLD FRONT ALONG 32N63W TO 23N79W NEAR THE COAST OF CENTRAL CUBA. WINDS TO GALE FORCE EXPECTED N OF 25N AND W OF 75W...OFF OF NE FLORIDA...BUT THIS IS EXPECTED TO RELAX BY TOMORROW AFTERNOON. LARGE NE WIND WAVES AND SWELL TO SPREAD THROUGH THE SOUTH FLORIDA WATERS INTO SAT...SUBSIDING SLOWLY THROUGH EARLY NEXT WEEK. SEE DETAILS IN COASTAL WATERS FORECASTS FROM LOCAL WEATHER SERVICE OFFICES. 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 SCATTERED MODERATE CONVECTION SEEN N OF 23N BETWEEN 60W-68W. THIS IS ALSO GETTING LIFT FROM A PREFRONTAL TROUGH ALONG 30N64W 23N71W...WHICH SEEMS TO BE GETTING TAKEN OVER BY THE MAIN COLD FRONT. AN UPPER TROUGH EXTENDS FROM THE E ATLC NEAR 32N30W SW TO NEAR 13N52W. AN UPPER RIDGE EXTENDS UP THE COAST OF W AFRICA...WHICH HAS ABUNDANT MID TO UPPER MOISTURE SPREADING AROUND ITSELF. THE SFC PATTERN OVER THE E AND CENTRAL ATLC REMAINS DOMINATED BY E FLOW ON THE SRN PERIPHERY OF A 1039 MB HIGH OVER THE AZORES. $$ WILLIS