000 AXPZ20 KNHC 112205 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN DEC 11 2011 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 09N84W TO 06N92W WHERE LOW LEVEL WINDS SUGGEST THAT THE ITCZ BEGINS AND EXTENDS TO 06N100W TO 07N110W TO 07N121W TO 11N140W. SCATTERED MODERATE CONVECTION IS NOTED N OF 05N E OF 82W. ...DISCUSSION... AN UPPER LEVEL TROUGH EMBEDDED IN A VERY ACTIVE SRN STREAM BRANCH EXTENDS FROM 25N124W SW TO 17N125W TO NEAR 10N125W. THE TROUGH IS MOVING RAPIDLY EASTWARD. STRONG WLY UPPER WINDS ARE NOTED BOTH AHEAD AND BEHIND THE TROUGH. THESE WINDS ARE TRANSPORTING EXTENSIVE DEEP MID TO UPPER LEVEL MOISTURE IN THE FORM OF BROKEN HIGH CLOUDS EASTWARD ACROSS MOST OF THE NORTHERN PORTIONS OF THE AREA. THIS MOISTURE THEN ACHIEVES MORE OF AN EASTWARD TRAJECTORY OVER THE NE PORTION AS IT RIDES UP OVER THE NORTHERN PERIPHERY OF AN UPPER ANTICYLONE NEAR 14N113W AND TOWARDS BAJA CALIFORNIA...SRN CALIFORNIA AND TO ACROSS MUCH NORTHERN AND CENTRAL MEXICO AS WELL. THE TROUGH IS FORECAST TO QUICKLY DAMPEN OUT AS IT MOVES EASTWARD THROUGH MON...AND WHILE AT THE SAME TIME A RATHER VIGOROUS DEEP UPPER TROUGH JUST N OF THE AREA FROM THE PACIFIC NW SW TO 32N130W SWINGS SOUTHEASTWARD INTO THE NE PORTION OF THE AREA. THE ANTICYCLONE NEAR 14N113W DOMINATES THE REMAINDER OF THE NE PACIFIC ALLOWING FOR SUBSIDENCE AND DRY ENVIRONMENTAL CONDITIONS TO PREVAIL OVER THIS AREA. A SURFACE RIDGE EXTENDS FROM NEAR 32N138W SOUTHEASTWARD TO NEAR 24N130W TO 20N1190W. HIGH PRES COVERS THE AREA GENERALLY TO THE N OF 17N. THE COMBINATION OF THE RIDGE WITH ITCZ ASSOCIATED LOW PRESSURE IS SUSTAINING FRESH E-NE WINDS FROM 08N TO 21N W OF 128W WITH SEAS THERE IN THE 9 TO 11 FT RANGE. AS THE ABOVE UPPER TROUGH SHIFTS EASTWARD ACROSS SRN CALIFORNIA AND NRN BAJA MON...A 1031 MB HIGH WILL BECOME ESTABLISHED IN ITS WAKE NEAR 36N140W. THIS SET UP WILL BEGIN TO EXPAND THIS AREA OF NE TO E WINDS FROM ABOUT 08N TO 25N W OF 132W IN 24 HRS...AND FROM 09N TO 18N W OF 130W BY 48 HRS. SEAS SHOULD SUBSIDE SOME TO ABOUT 9 FT BY 48 HRS. GULF OF TEHUANTEPEC...N TO NE WINDS OF 20-30 KT WITH BRIEF GUSTS TO GALE FORCE CONTINUE TO SURGE SWD THROUGH THE GULF AS A STRONG PRES GRADIENT OVER SRN MEXICO AND JUST INLAND THE GULF KEEPS CONTROL OF THE WIND REGIME THERE. SEAS OF UP TO 14 FT ARE POSSIBLE IN THE GULF. CONDITIONS ARE EXPECTED TO REMAIN WITH LITTLE CHANGE THROUGH MON EVENING...THEN BEGIN TO DIMINISH GRADUALLY INTO TUE AS THE GRADIENT SLACKENS. THE DEEP UPPER TROUGH FORECAST TO SWING ESE TOWARDS CALIFORNIA ON MON...AS MENTIONED ABOVE...WILL DEEPEN INTO A CLOSED LOW OFFSHORE SRN CALIFORNIA LATE SUN AND THROUGH MON EVENING AS IT BREAKS OFF FROM NRN STREAM ENERGY. AN ASSOCIATED SURFACE WEAKENING COLD FRONT WILL EXTEND FROM THE LOW SW TO NEAR 22N123W BY MON EVENING. THE PRES GRADIENT BETWEEN THIS LOW AND THE 1029 MB HIGH NEAR 36N140W EARLY NEXT WEEK WILL INITIATE NW TO N WINDS OF 20 TO 25 KT N OF 25N BETWEEN 122W AND 132W WITH NW SWELLS LEADING TO 10 TO 15 FT BY MON AFTERNOON BY THE WAVEWATCH MODEL GUIDANCE. SCATTERED SHOWERS ARE EXPECTED WITH THE LOW AND ALONG THE FRONT. ELSEWHERE W OF FRONT WINDS ARE EXPECTED TO BE N TO NE AT 20 KT WITH SEAS 8 TO 10 FT IN A NW TO N SWELL. SW TO W WINDS OF 20 KT ARE FORECAST TO THE E OF THE FRONT AND S OF THE LOW ON MON WITH SEAS 8 TO 10 FT IN A NW SWELL. GULF OF PAPAGAYO...NE WINDS OF 20 KT ARE EXPECTED TO PULSATE ON AND OFF PRIMARILY DURING THE LATE NIGHT AND EARLY MORNING IN DRAINAGE FLOW OFF THE LAND. HOWEVER...THESE WINDS ARE NOT EXPECTED TO COVER A LARGE ENOUGH AREA FOR MENTION IN THE NE PACIFIC HIGH SEAS FORECAST. $$ AGUIRRE