000 AXPZ20 KNHC 310349 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON DEC 31 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 07N77W TO 09N85W TO LOW PRES NEAR 05N90W 1010 MB TO 06N97W. THE ITCZ CONTINUES FROM 07N97W TO 10N110W TO 05N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM S OF MONSOON TROUGH AXIS E OF 90W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED FROM 11N TO 16N BETWEEN 105W AND 115W. ...DISCUSSION... E OF 110W... GULF OF TEHUANTEPEC...WINDS TO GALE FORCE CONTINUE THROUGH THE GULF OF TEHUANTEPEC THIS EVENING...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 HIGH PRES OVER THE GULF OF MEXICO AND FRESH NORTHERLY BREEZES WINDS DELIVERING DENSE COOL AND DRY AIR THROUGH THE TEHUANTEPEC ISTHMUS IS ALLOWING THE GALES TO PERSIST THROUGH TONIGHT. 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 MODERATE CONVECTION 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 28N BETWEEN 118W AND 124W...ON THE EDGE OF 1027 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