000 AXPZ20 KNHC 302117 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE DEC 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2030 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF COLOMBIA NEAR 6N77W TO 6N87W WHERE IT TRANSITIONS TO THE ITCZ AND CONTINUES ALONG 4N115W TO 7N140W. NO SIGNIFICANT CONVECTION. ...DISCUSSION... A NEGATIVELY TILTED MID TO UPPER LEVEL TROUGH PERSISTS FROM THE N CENTRAL PACIFIC N OF HAWAII SOUTHEASTWARD TOWARD A CLOSED UPPER LOW NEAR 24N135W. AN ASSOCIATED 1014 MB SURFACE LOW IS CENTERED NEAR 26N138W WITH A WEAKENING COLD FRONT EXTENDING ALONG 20N134W THEN W TO 15N140W. AN 1800 UTC ASCAT SCATTEROMETER PASS CONTINUES TO INDICATED FRESH TO STRONG SE FLOW NE OF THE LOW...BETWEEN THE LOW PRES CENTER AND AN ELONGATED SURFACE RIDGE AXIS WHICH IS PARALLELING THE U.S. WEST COAST AND THE COAST OF BAJA CALIFORNIA. INSTABILITY ASSOCIATED WITH THE UPPER TROUGH IS SUSTAINING AREAS OF SHOWERS WITHIN 350 NM NE AND E OF THE FRONT. THE UPPER TROUGH WILL WEAKEN AS IT SHIFTS EASTWARD OVER THE NEXT COUPLE OF DAYS TOWARD THE BAJA CALIFORNIA PENINSULA...EVENTUALLY COMING INTO PHASE WITH ANOTHER MID/UPPER IMPULSE MOVING SOUTHWARD DOWN THE WESTERN UNITED STATES. THE LOW PRES WILL OPEN INTO A TROUGH AND THE FRONT WILL BECOME DIFFUSE LATER TONIGHT/EARLY WED...WITH WINDS AHEAD OF THE FRONT DIMINISHING AS WELL. GULF OF CALIFORNIA...A COLD FRONT ASSOCIATED WITH THE MID/UPPER TROUGH MOVING SOUTHWARD ACROSS THE WESTERN UNITED STATES WILL MOVE INTO BAJA CALIFORNIA NORTE AND THE NORTHERN GULF OF CALIFORNIA TONIGHT/EARLY WED...THEN BECOME DIFFUSE AS IT SHIFTS FURTHER SOUTHWARD DOWN THE PENINSULA. THERE MAY BE A BRIEF PERIOD OF FRESH TO STRONG SW WINDS OVER THE NORTHERN GULF OF CALIFORNIA TONIGHT...CONNECTED TO WEAK AND TRANSIENT LOW MOVING INLAND OVER S CALIFORNIA THIS EVENING. LOOKING AHEAD...HIGH PRES BUILDING OVER THE GREAT BASIN WILL SUPPORT DEVELOPMENT OF FRESH NW FLOW DOWN THE LENGTH OF THE GULF OF CALIFORNIA BY LATE THU/EARLY FRI. SHORTER PERIOD NORTHERLY SWELL GENERATED BY STRONG NORTHERLY WINDS OFF THE COAST OF CALIFORNIA WITH COMBINED SEAS TO 8 FT WILL PROPAGATE SOUTH OF 30N WED...IMPACTING THE AREA N OF 29N BETWEEN 118W AND 126W BEFORE SUBSIDING BELOW 8 FT BY EARLY THU. GAP WINDS...STRONG HIGH PRES OVER THE NORTHERN PLAINS WILL MOVE SOUTHWARD ALONG THE FRONT RANGE OF THE ROCKIES INTO THE SOUTHERN PLAINS THROUGH LATE WED. ALTHOUGH WELL REMOVED FROM THE EASTERN PACIFIC...THE STRENGTH OF THE HIGH PRES WILL INITIATE CONDITIONS FAVORABLE FOR STRONG GAP WINDS THROUGH THE GULFS OF TEHUANTEPEC AND PAPAGAYO STARTING TONIGHT. FOR THE GULF OF TEHUANTEPEC...WINDS WILL REACH AT LEAST 30 KT TONIGHT WITH SEAS BUILDING AS HIGH AS 10 FT BY WED AFTERNOON. THE HIGH PRES SHIFTS FARTHER SOUTH THROUGH LATE WED...ALLOWING GAP WINDS TO GALE FORCE THROUGH EARLY THU AND SEAS TO 12 FT. WINDS WEAK TO BELOW GALE FORCE AND SEAS DIMINISH 10 FT THU AS THE HIGH PRES WEAKENS AND SHIFTS EAST. GULF OF PAPAGAYO...GAP WINDS WILL PULSE TO 30 KT OVER THE NEXT COUPLE OF NIGHTS WITH SEAS BUILDING AS HIGH AS 9 TO 11 FT...WITH FURTHER EVENTS TO 25 KT INTO THE WEEKEND. $$ PAW