000 AXPZ20 KNHC 240903 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED DEC 24 2014 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...A COLD FRONT IS MOVING SOUTHWARD ACROSS THE GULF OF MEXICO THIS MORNING. COOL...DENSE AIR ASSOCIATED WITH THE HIGH PRES BEHIND THE FRONT WILL FUNNEL THROUGH THE TEHUANTEPEC ISTHMUS INTO THE GULF OF TEHUANTEPEC THIS AFTERNOON. GAP WINDS TO GALE FORCE CAN BE EXPECTED BY THIS EVENING WITH SEAS BUILDING AS HIGH AS 17 FT BY EARLY THU. THE HIGH PRES OVER THE GULF OF MEXICO WILL WEAKEN AND SHIFT EAST THROUGH THU...ALLOWING THE GAP WINDS IN THE GULF OF TEHUANTEPEC TO DIMINISH BELOW GALE FORCE THU...AND BELOW 20 KT BY EARLY FRI. NE SWELLS IN EXCESS OF 8 FT WILL PROPAGATE SW AWAY FROM THE GULF AFTER THE ONSET OF THE GALE EVENT...AND REACH TO NEAR 102W FROM 09N TO 14N BETWEEN 94W AND 102W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N87W TO 07N100W...WHERE IT TRANSITIONS TO AN ITCZ THAT EXTENDS TO 06N105W THEN TO BEYOND 07N140W. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 45 NM OF MONSOON TROUGH BETWEEN 92W AND 93W. ...DISCUSSION... DEEP LAYER HIGH PRES CENTERED N OF THE AREA NEAR 38N130W IS SUPPORTING MODERATE TO FRESH TRADE WINDS OVER THE TROPICAL WATERS FROM THE ITCZ TO ROUGHLY 15N W OF 125W. THE MAIN INFLUENCE ON THE REGIONAL WEATHER IS INCREASINGLY BECOMING A SHARP UPPER TROUGH/CUTOFF UPPER LOW N OF HAWAII. THE PATTERN BETWEEN 110W AND 140W IS TRANSITIONING FROM A MORE TYPICAL TRADE WIND PATTERN TO A PATTERN EMPHASIZING A TIGHTENING PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE N OF AREA AND DEEPENING LOW PRES W OF THE AREA. THIS WILL RESULT IN INCREASING SE WINDS N OF 25N W OF 135W BY LATE FRI...WITH GENERALLY MODERATE TRADE WINDS FARTHER SOUTH. MEANWHILE SHORT WAVE ENERGY IN THE NW FLOW ALOFT WILL MOVE ACROSS THE U.S. WEST COAST...TO THE EAST OF A DEEP LAYER RIDGE ALONG 140W. THIS WILL SUPPORT PASSAGE OF A WEAK COLD FRONT OVER BAJA CALIFORNIA NORTE AND ADJACENT PACIFIC WATERS E OF 125W FRI AND SAT. SHORT PERIOD NW TO N SWELL GENERATED BY PERSISTENT STRONG WINDS BETWEEN THE HIGH PRES AND THE COAST OF CALIFORNIA WILL DELIVER 12 TO 13 FT SEAS N OF 28N BETWEEN 115W AND 125W BY LATE THU...DECAYING TO BELOW 10 FT BY LATE FRI. SEAS 8 TO 10 FT IN MIXED NW AND N SWELL WILL PERSIST N OF 23N BETWEEN 115W AND 130W THROUGH LATE FRI. GULF OF CALIFORNIA...STRONG HIGH PRES N OF THE AREA CENTERED OVER THE GREAT BASIN IS SUPPORTING NW WINDS TO NEAR GALE FORCE ACROSS THE GULF OF CALIFORNIA THIS MORNING WITH SEAS TO 8 FT. THE HIGH PRES WILL WEAKEN AND SHIFT EAST TODAY ALLOWING THE WINDS TO SUBSIDE BELOW 20 KT THROUGH LATE TODAY. EXPECT FRESH NORTHERLY FLOW OVER THE NORTHERN GULF OF CALIFORNIA BY SAT NIGHT BEHIND THE PASSAGE OF THE WEAK COLD FRONT. AN UPPER LOW CENTERED NEAR 12.5N110W HAS BECOME TEMPORARILY CUT OFF FROM THE MAIN TROUGH OVER MEXICO. UPPER DIVERGENCE CONTINUES TO SUPPORT AREAS OF SHOWERS AND THUNDERSTORMS EAST OF THE UPPER LOW...FROM 11N TO 17N BETWEEN 102W AND 107W. THIS CONVECTION WILL LIKELY DIMINISH THROUGH TONIGHT AS THE SUPPORTING UPPER LOW WEAKENS AND LIFTS NE. GULF OF PAPAGAYO...MODEL GUIDANCE INDICATES THAT THE NEXT NE 20-25 KT SURGE THROUGH THE GULF WILL BEGIN LATE ON THU INTO EARLY FRI. $$ CHRISTENSEN