000 AXPZ20 KNHC 100359 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN DEC 10 2006 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG...6N77W 5N100W 5N118W 7N133W 6N140W. SCATTERED MODERATE WITHIN 60-90 NM OF AXIS W OF 129W. ...DISCUSSION... A VERY PROGRESSIVE AND ACTIVE PATTERN DOMINATES THE REGION WITH A MID TO UPPER LEVEL TROUGH MOVING ACROSS MEXICO GENERALLY FROM THE RIO GRANDE VALLEY SWWD TO 17N105W...AND A SECOND MORE PRONOUNCED TROUGH MOVING INTO THE NORTHERN PORTION OF THE AREA EXTENDING FROM 30N126W TO 20N140W. THIS TROUGH IS IN THE PROCESS OF FRACTURING AS THE NORTHERN PORTION SWEEPS EWD AT 40 KT WHILE THE SRN PORTION LAGS BEHIND. IN BETWEEN THE TROUGHS A BROAD RIDGE COVERS THE AREA WITH A MEAN AXIS EXTENDING FROM A MID/UPPER LEVEL ANTICYCLONIC CIRCULATION NEAR 9N126W NORTHEASTWARD THROUGH 20N115W TO A CREST WELL NORTH OF THE REGION OVER THE FOUR CORNERS REGION OF THE CONUS. A SHEARED MID/UPPER LEVEL CYCLONIC CIRCULATION...LEFT BEHIND BY THE FIRST TROUGH IS BECOMING ILL DEFINED AND OBSCURED BY HIGHER LEVEL CLOUDS WITHIN 60 NM EITHER SIDE OF A LINE FROM 21N131W 17N141W. STRONG UPPER LEVEL SUBSIDENCE AND ASSOCIATED DRY AIR IN THE WAKE OF THE FIRST TROUGH COVERS THE AREA N OF 16N AND E OF 115W OVER MOST OF MEXICO. CONFLUENT FLOW INTO THE BASE OF THE SECOND TROUGH IS ALSO RESULTING IN A NARROW BAND OF MODERATE TO STRONG SUBSIDENCE WITHIN 120 NM EITHER SIDE OF A LINE THROUGH 27N127W 23N140W. LIMITED UPPER LEVEL MOISTURE IS SEEN OVER THE EASTERN PORTION OF THE AREA FROM 9N-15N BETWEEN 90W AND 108W. DIFLUENT MID TO UPPER LEVEL FLOW WEST OF THE ANTICYCLONIC CIRCULATION NEAR 9N127W IS SUPPORTING SOME ITCZ CONVECTION W OF 129W. AT THE SURFACE...THE SURFACE TROUGH ANALYZED EARLIER HAS DISSIPATED. A COLD FRONT EXTENDS FROM 32N122W 25N135W AND DISSIPATING TO 24N140W. NORTHWEST WINDS HAVE DECREASED TO 25 KT BEHIND THE FRONT. HOWEVER...THE MAIN ISSUE FACING THE REGION WITH RESPECT TO THE FRONT REMAINS THE VERY LARGE NW-N SWELLS THAT CONTINUE TO SPREAD SEWD THROUGHOUT MUCH OF THE WESTERN AND CENTRAL SECTIONS OF THE DISCUSSION AREA OVER THE NEXT FEW DAYS AS THE COLD FRONT THE COLD FRONT IS FORECAST TO QUICKLY MOVE EASTWARD AND WEAKEN OVER THE EASTERN PART OF THE REGION NEAR THE SOUTHERN CALIFORNIA AND NORTHERN BAJA COAST. WAVEWATCH MODEL FORECASTS SEAS TO REMAIN IN THE 15 TO 20 FT RANGE THROUGH 18-24 HOURS THEN SLOWLY SUBSIDE TO 12 TO 18 FT BY 48 HOURS. SEVERAL BUOY AND SHIP OBSERVATIONS JUST NORTH OF THE REGION INDICATE MAXIMUM SEAS TOPPING OUT IN THE 20 FT RANGE. OVER THE FAR EASTERN PART OF THE REGION A MID TO UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONE OVER NRN VENEZUELA WESTWARD ALONG 12N/13N TO 105W. THE RIDGE WAS BECOMING SUPPRESSED WITH TIME AS WESTERLIES IN ADVANCE OF THE TROUGH OVER MEXICO CONTINUE TO DROP SWD. THIS RIDGE IS EMBEDDED IN THE AREA OF MODERATE TO STRONG SUBSIDENCE DESCRIBED EARLIER IN THE DISCUSSION. GAP WINDS... SURFACE OBSERVATIONS FROM SALINA CRUZ INDICATE NLY WINDS HAVE DROPPED OFF TO 20 KT OVER THE PAST SEVERAL HOURS SUGGESTING A MODERATION OF THE GULF OF TEHUANTEPEC GALE. HOWEVER...A 0104 UTC QUIKSCAT PASS REVEALED A TENACIOUS GALE EVENT WITH 40-45 KT WINDS STILL NOTED IN THE GULF OF TEHUANTEPEC. NONETHELESS THE WINDS SHOULD DECREASE TO LESS THAN GALE FORCE WITHIN 24 HOURS. AS RETURN SLY FLOW SETS UP OVER THE WRN GULF OF MEXICO. NE WINDS OF 20 KT ACROSS THE GULF OF PAPAGAYO WEST TO 88W ARE EXPECTED TO CONTINUE THROUGH THE NEXT 48 HOURS THEN DIMINISH TO LESS THAN 20 KT. $$ COBB