000 AXPZ20 KNHC 091636 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT DEC 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1615 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG...5N78W 6N90W 7N100W 6N110W 6N120W 6N130W 6N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90-120 NM N OF AXIS BETWEEN 125W AND 138W. ...DISCUSSION... A VERY PROGRESSIVE AND ACTIVE PATTERN DOMINATES THE REGION WITH A MID TO UPPER LEVEL TROUGH NOW HAVING MOVED INLAND TO OVER EASTERN MEXICO...AND A SECOND MORE PRONOUNCED TROUGH HAVING JUST ENTERED THE NORTHWEST PORTION OF THE AREA FROM 30N135W TO 25N140W. IN BETWEEN THE TROUGHS A BROAD RIDGE COVERS THE AREA WITH A MEAN AXIS EXTENDING FROM A MID/UPPER LEVEL ANTICYCLONIC CIRCULATION NEAR 9N128W NORTHEASTWARD THROUGH 17N124W THROUGH 24N120W TO A CREST WELL NORTH OF THE REGION OVER SOUTHERN CALIFORNIA. AN ELONGATED MID/UPPER LEVEL CYCLONIC CIRCULATION...LEFT OVER FROM THE FIRST TROUGH EXTENDS WITHIN 60 NM EITHER SIDE OF A LINE FROM 24N129W SOUTHWEST TO 18N140W. STRONG UPPER LEVEL SUBSIDENCE AND ASSOCIATED DRY AIR IN THE WAKE OF THE FIRST TROUGH COVERS THE AREA NORTH OF 14N AND EAST OF 120W. CONFLUENT FLOW INTO THE BASE OF THE SECOND TROUGH IS ALSO RESULTING IN MODERATE TO STRONG OVER THE NORTHWEST PART OF THE AREA NORTH OF 23N WEST OF 130W. LIMITED UPPER LEVEL MOISTURE IS SEEN OVER THE EASTERN PORTION OF THE AREA FROM 9N-14N BETWEEN 97W-107W...HOWEVER IT HAS DECREASED IN COVERAGE OVER THE PAST 24 HOURS AS THE SUBSIDENCE AREA DESCRIBED CONTINUES TO PRESS EASTWARD DRYING THE ATMOSPHERE OVER THIS AREA. MID/UPPER LEVEL RIDGING EXTENDING EAST TO WEST ALONG 10N WEST OF 117W IN ASSOCIATION WITH THE MID/UPPER ANTICYCLONIC CIRCULATION NEAR 9N128W IS SUPPORTING ITCZ CONVECTION WEST OF 124W. AT THE SURFACE...A DISSIPATING FRONT EXTENDS FROM 32N120W TO 23N130W. A COLD FRONT EXTENDS FROM 30N132W TO 25N140W. NORTHWEST WINDS HAVE DECREASED TO 20-25 KT BEHIND THE FRONT. HOWEVER... THE MAIN PROBLEM AFFECTING THE REGION WITH RESPECT TO THE FRONTS ARE THE VERY LARGE NW-N SWELLS THAT CONTINUE TO SPREAD THROUGHOUT MUCH OF THE WESTERN AND CENTRAL SECTIONS OF THE DISCUSSION AREA OVER THE NEXT FEW DAYS AS THE FRONT WEAKENS AND DISSIPATES. WAVEWATCH MODEL INDICATES MAXIMUM WAVE HEIGHTS TO BE LESS THAN THE 24 FT IT HAD PREVIOUSLY FORECASTED...HOWEVER NUMEROUS BUOY AND SHIP OBSERVATIONS JUST NORTH OF THE REGION INDICATE MAXIMUM SEAS TOPPING OUT IN THE 20-28 FT RANGE. EXPECT VERY LARGE SWELLS...POSSIBLY IN THE 17-20 FT RANGE TO SPREAD INTO THE NORTHWEST PORTION THROUGH THE NEXT 24 HOURS THEN SUBSIDE TO 17 FT IN ABOUT 24 HOURS AND SLOWLY CONTINUE TO SUBSIDE THEREAFTER. 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. SWELLS BEHIND THIS FRONT ARE NOT EXPECTED TO EXCEED 18 FT BASED ON LATEST AVAILABLE WAVEWATCH MODEL GUIDE. OVER THE FAR EASTERN PART OF THE REGION A MID TO UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN WEST-SOUTHWEST ALONG 12N TO 97W. THIS RIDGE IS EMBEDDED IN THE AREA OF MODERATE TO STRONG SUBSIDENCE DESCRIBED EARLIER IN THE DISCUSSION. GAP WINDS... A SHIP WITH CALL SIGN DEHY LOCATED NEAR 14.5N94W OR ROUGHLY ABOUT 160 NM FROM THE ENTRANCE TO THE GULF OF TEHUANTEPEC REPORTED 30 KT WINDS AT 1200 UTC. ALTHOUGH JUST BELOW GALE FORCE...A QUIKSCAT PASS FROM NEAR 1230 UTC THIS MORNING REVEALED 30-40 KT NORTH WINDS ACROSS THE GULF OF TEHUANTEPEC NORTH OF 14N BETWEEN 94W-96W. THIS JUSTIFIES CURRENT GULF OF TEHUANTEPEC GALE EVENT. THIS EVENT SHOULD DIMINISH IN ABOUT 24 HOURS. 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. $$ AGUIRRE