000 AXPZ20 KNHC 011540 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE JAN 1 2013 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 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 07N78W TO 06N104W TO 09N111W. THE ITCZ EXTENDS FROM 10N115W TO 07N121W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS N OF THE CONVERGENCE ZONE FROM 14N TO 18N BETWEEN 104W AND 112W. ...DISCUSSION... SUBTROPICAL RIDGE CENTERED NEAR 1027 MB HIGH AT 30N131W REMAINS PRIMARY SYNOPTIC FEATURE OVER NORTHERN PART OF DISCUSSION AREA. A SLOW-MOVING COLD FRONT EXTENDS OVER LARGE SWATH OF THE CENTRAL PACIFIC FROM 45N142W TO THE HAWAIIAN ISLANDS. THE FRONT WILL SHIFT EASTWARD AND WEAKEN THROUGH WED WHILE THE SUBTROPICAL HIGH REMAINS FIRMLY ENTRENCHED...BUT WEAKER...CENTERED NEAR 28N131W. THE FRONT WILL EXTEND ACROSS THE NW PORTION WED...FROM 40N133W TO 32N135W TO 25N145W. WINDS ASSOCIATED WITH THE FRONT WILL BE LESS THAN 25 KT...BUT LARGE LONG PERIOD NW SWELL GENERATED IN THE CENTRAL PACIFIC WILL PUSH INTO NW CORNER OF THE DISCUSSION AREA WED WITH SEAS BUILDING TO 13-14 FT BEHIND THE FRONT. THE WEAKENED SUBTROPICAL HIGH WILL CAUSE AN AREA OF FRESH TO STRONG NE TO E TRADE WINDS S OF THE RIDGE...ROUGHLY W OF A LINE FROM 22N112W TO 10N120W TO 06N140W...TO SHRINK AND SHIFT WESTWARD TO 135W-140W THROUGH THU. AS A RESULT...BY THURSDAY WINDS 20 KT OR LESS WILL PREVAIL ACROSS NEARLY ALL OF THE FORECAST AREA EXCEPT FOR SMALL AREAS OF GAP WINDS IN THE NORTHERN GULF OF CALIFORNIA AND THE GULF OF TEHUANTEPEC. SEA HEIGHTS WILL GRADUALLY SUBSIDE ACROSS THE TRADE WIND BELT THROUGH FRI NIGHT AS THE PRESSURE GRADIENT WEAKENS ACROSS THE REGION. GAP WINDS... GULF OF TEHUANTEPEC...GLOBAL MODELS SUGGEST THE NEXT HIGH WIND EVENT FOR THE GULF OF TEHUANTEPEC WILL COMMENCE THU MORNING AND PERSIST THROUGH SAT AS HIGH PRES BUILDS SOUTHWARD ALONG THE EAST COAST OF MEXICO. GFS AND ECWMF GLOBAL MODELS SHOW WINDS REACHING GALE FORCE EARLY FRI MORNING WITH ANOTHER PEAK OF 35 KT WINDS EARLY SAT MORNING. GULF OF PAPAGAYO...ASCAT SHOWS WINDS HAVE DIMINISHED BELOW 25 KT DOWNWIND FROM THE GULF OF PAPAGAYO. A FEW PULSES TO 20-25 KT CAN BE EXPECTED THROUGH FRI MORNING...BUT SEAS GENERATED BY THE HIGH WINDS HAVE PROPAGATED WELL AWAY FROM THE SOURCE REGION...BETWEEN 94W AND 112W...AND WILL CONTINUE TO SUBSIDE THROUGH FRI. GULF OF CALIFORNIA...HIGH PRESSURE BUILDING OVER THE GREAT BASIN ALONG WITH LOW PRESSURE OVER NORTH-CENTRAL MEXICO WILL ALLOW NW WINDS TO INCREASE TO 20-25 KT IN THE NORTHERN GULF OF CALIFORNIA TONIGHT...THEN PERSIST WITH LITTLE CHANGE THROUGH THU. $$ MUNDELL