000 AXPZ20 KNHC 302202 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN DEC 30 2012 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 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 07N78W TO 08N102W. ITCZ CONTINUES FROM 08N102W TO 10N120W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 120 NM S OF MONSOON TROUGH AXIS E OF 90W...AND FROM 11N TO 15N BETWEEN 105W AND 120W. ...DISCUSSION... E OF 110W... GULF OF TEHUANTEPEC...STRONG GALES CONTINUE THROUGH THE GULF OF TEHUANTEPEC THIS AFTERNOON...WITH A LONG PLUME OF 20 TO 25 KT WINDS AND SEAS IN EXCESS OF 8 FT EXTENDING AS FAR AS 600 NM TO THE SW OF THE GULF AREA. THE COMBINATION OF 1029 MB HIGH PRES CENTERED OVER E CENTRAL MEXICO AND FRESH TO STRONG NORTHERLY WINDS DELIVERING DENSE COOL AND DRY AIR THROUGH THE TEHUANTEPEC ISTHMUS IS ALLOWING THE GALES TO PERSIST. THE WINDS WILL GRADUALLY DIMINISH THROUGH EARLY MON AS THE AIRMASS OVER THE GULF OF MEXICO MODIFIES AND SHIFTS EAST. ACCORDINGLY SEAS WILL SUBSIDE FROM AN ESTIMATED 16 FT CURRENTLY TO BELOW 8 FT BY LATE MON. GULF OF PAPAGAYO...HIGH PRES N OF THE CARIBBEAN IS ENHANCING NE TO E TRADE WIND FLOW ACROSS THE SW CARIBBEAN...WHICH IN TURN IS PENETRATING INTO THE PACIFIC THROUGH THE GULF OF PAPAGAYO...FROM WHICH A PLUME OF 20 TO 25 KT NE TO E WINDS AND SEAS OF 8 TO 10 FT WILL REACH AS FAR AS 700 NM INTO THE PACIFIC THROUGH EARLY MON...WHEN THE EVENT IS AT ITS MAXIMUM INTENSITY. CLUSTERS OF CONVECTION PERSIST MAINLY S OF THE MONSOON TROUGH E OF 90W...DUE IN PART TO MODERATE TO FRESH SW BREEZES CONVERGING INTO THE MONSOON TROUGH...AND DIVERGENT SE WINDS ALOFT BETWEEN AN UPPER EQUATORIAL CIRCULATION NEAR THE GALAPAGOS AND A BROAD UPPER ANTICYCLONE CENTERED OVER THE N CENTRAL CARIBBEAN. W OF 110W... A SHARP LONG WAVE UPPER TROUGH EXTENDS FROM OVER THE UPPER ROCKIES ACROSS SOUTHERN CALIFORNIA TO 06N132W. THE MAIN ENERGY ALONG THIS FRONT IS LIFTING NE ACROSS NORTHERN BAJA...AWAY FROM AN ASSOCIATED COLD FRONT FROM THE NORTHERN GULF OF CALIFORNIA THROUGH CENTRAL BAJA TO 22N125W. THE FRONT WILL GRADUALLY DISSIPATE AS IT DRIFTS WEST THROUGH MON. SCATTEROMETER DATA INDICATED RESIDUAL 20 TO 25 KT NW WINDS N OF 29N BETWEEN 120W AND 122W...ON THE EDGE OF 1029 MB HIGH PRES SETTLING BEHIND THE FRONT NEAR 30N135W. UPPER DIVERGENCE ON THE SE SIDE OF THE UPPER TROUGH CONTINUES TO SUPPORT CLUSTERS OF SHOWERS AND THUNDERSTORMS OVER A LARGE AREA N OF THE ITCZ AXIS FROM 11N TO 15N BETWEEN 105W AND 120W...AS WELL AS SUPPORTING THE FORMATION OF A SURFACE TROUGH ALONG THE ITCZ NEAR 120W. THIS TROUGH IS EXPECTED TO DIMINISH THROUGH TONIGHT AS HIGH PRES BUILDS IN...BUT GLOBAL MODELS SUGGEST THE FORMATION OF ANOTHER SURFACE TROUGH NEAR 110W BY MON AS THE UPPER TROUGH MIGRATES EASTWARD. THE PRESENCE OF THESE TROUGHS ALONG WITH THE HIGH PRES ALONG 30N135W IS MAINTAINING A LARGE WEDGE SHAPED AREA OF 20 TO 25 KT TRADE WINDS BETWEEN 10N AND 20N W OF 115W. MEANWHILE...NW SWELL OF 8 TO 12 FT WITH PERIODS TO 16 SECONDS WILL GRADUALLY DECAY AS IT CONTINUES TO PUSH ACROSS THE AREA...AND WILL COVER MOST OF THE WATERS W OF 110W BY LATE MON. THIS WILL BE FOLLOWED BY ANOTHER ROUND OF SIMILAR NW SWELL WILL ENTER THE NW CORNER OF THE DISCUSSION AREA LATE TONIGHT...AND REACH FROM 30N130W TO 20N140W BY LATE MON. $$ CHRISTENSEN