000 AXPZ20 KNHC 091559 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED DEC 09 2015 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A TROUGH EXTENDS FROM 06N77W TO 04N81W TO 05N96W TO 06N101W. THE ITCZ REACHES FROM 05N100W TO 07N110W TO 04N125W TO 03N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM N OF ITCZ BETWEEN 120W AND 125W. ...DISCUSSION... N OF 15N W OF 120W...THE PRESSURE GRADIENT REMAINS RELATIVELY RELAXED ACROSS THE REGION FOR NOW WITH WEAK TROUGHING ALONG THE GULF OF CALIFORNIA AND BAJA CALIFORNIA PENINSULA...AND 1024 MB HIGH PRES CENTERED WEST OF THE AREA. A PAIR OF SHIP OBSERVATIONS INDICATED MODERATE TO FRESH NW WINDS IN THE SOUTHERN PORTIONS OF THE GULF OF CALIFORNIA EARLIER...BUT THIS HAS DIMINISHED SLIGHTLY THIS MORNING. THE MAIN ISSUE CONTINUES TO BE LONG PERIOD NW SWELL OF 8 TO 10 FT PROPAGATING INTO THE REGION...REACHING THE ENTIRE WEST COAST OF BAJA CALIFORNIA...MOST OF THE AREA BETWEEN LOS CABOS AND CABO CORRIENTES...AND THE WATERS WEST OF 105W FARTHER SOUTH. THE SWELL WILL SUBSIDE SLIGHTLY THROUGH THU...BUT BE FOLLOWED BY ANOTHER ROUND OF NW SWELL THU NIGHT ASSOCIATED WITH AN APPROACHING COLD FRONT. THE FRONT WILL MOVE SOUTHEASTWARD ACROSS BAJA CALIFORNIA NORTE AND THE NORTHERN GULF OF CALIFORNIA THROUGH FRI. STRONG NW WINDS WILL FOLLOW THE FRONT BETWEEN THE COAST OF BAJA CALIFORNIA NORTE AND GUADALUPE ISLAND FRI MORNING WITH SEAS 12 TO 15 FT. THE STRONG WINDS WILL ALSO BRIEFLY IMPACT THE NORTHERN GULF OF CALIFORNIA FRI. LOOKING AHEAD...THE FRONT WILL MOVE SOUTH AND STALL FROM THE SOUTHERN GULF OF CALIFORNIA TO NEAR SOCORRO ISLAND SAT THEN BECOME DIFFUSE THROUGH SUN. THE STRONG NW WINDS OFF BAJA CALIFORNIA NORTE WILL DIMINISH BUT LINGERING NW SWELL OF 8 TO 10 FT WILL PERSIST INTO EARLY NEXT WEEK. GULF OF TEHUANTEPEC...WINDS HAVE DIMINISHED BELOW GALE FORCE EARLIER THIS MORNING...BUT EXPECT N TO NE 20 TO 30 KNOT WINDS THROUGH TONIGHT THEN DIMINISH TO 20 KT OR LESS BY THU AFTERNOON. AN ALTIMETER PASS FROM 1220 UTC INDICATED THE PLUME OF WAVE HEIGHTS IN EXCESS OF 8 FT GENERATED BY THE EARLIER GALES HAS SUBSIDED CONSIDERABLY. THIS IS NOT WELL INITIALIZED BY CURRENT WAVE GUIDANCE AND SHORT TERM ADJUSTMENTS TO THE FORECAST WILL HAVE TO BE MADE ACCORDINGLY. SHORTER PERIOD NE SWELL IS STILL LIKELY MIXING WITH MORE PREDOMINANT NW SWELL DOWNSTREAM OF TEHUANTEPEC...BUT WILL DAMPEN OUT QUICKLY. LOOKING AHEAD...LIGHT TO MODERATE GAP WINDS WILL PERSIST IN TEHUANTEPEC THROUGH SUNDAY...WITH A RETURN OF STRONG GAP WINDS EXPECTED EARLY NEXT WEEK. S OF 15N E OF 110W...AN EARLIER SCATTEROMETER PASS INDICATED FRESH TO STRONG GAP WINDS THROUGH THE GULF OF PAPAGAYO THIS MORNING. HIGH PRES N OF THE AREA IS EXPECTED TO WEAKEN...ALLOWING THESE WINDS TO GRADUALLY DIMINISH THROUGH THU. ANOTHER PULSE IS EXPECTED TONIGHT...BUT LIKELY NOT AS STRONG. ELSEWHERE AND AREA OF MIXED NW...NE AND SW SWELL PERSISTS WEST OF 90W...ALTHOUGH THE SHORTER PERIOD NE COMPONENT WILL LESSEN...THE OVERALL EXTENT OF SEAS 8 FT OR GREATER WILL SHRINK THROUGH THE END OF THE WEEK. LOOKING AHEAD...ANOTHER ROUND OF NW SWELL WILL MOVE INTO THE AREA WEST OF 100W BY LATE SAT. ELSEWHERE...FRESH TO OCCASIONALLY STRONG TRADE WINDS PERSIST FROM 09N TO 15N W OF 125W THIS MORNING BETWEEN 1024 MB HIGH PRES CENTERED NEAR 29N132W AND A WEAK TROUGH S OF 15N ALONG 125W. TRADE WIND CONVERGENCE ALONG WITH UPPER SUPPORT ON THE SOUTH SIDE OF A SHARP TROUGH IS SUPPORTING SCATTERED CONVECTION NORTH OF THE ITCZ...MAINLY BETWEEN 120W AND 125W. NW SWELL WITH WAVE HEIGHTS 8 TO 14 FT COVERS THE ENTIRE AREA W OF 120W. THE RIDGE WILL WEAKEN AHEAD OF A COLD FRONT MOVING ACROSS THE NE PACIFIC...ALLOWING THE TRADE WINDS TO DIMINISH. THE ONGOING SWELL WILL DECAY...BUT ANOTHER ROUND OF NW SWELL WILL ENTER THE WATERS N OF 25N W OF 130W BY LATE THU...WITH HEIGHTS 12 TO 17 FT. LOOKING AHEAD...TRADE WINDS WILL INCREASE AGAIN FROM 10N TO 15N W OF 130W BY FRI NIGHT AS HIGH PRES BUILDS N OF THE AREA AGAIN BEHIND THE FRONTAL BOUNDARY. $$ CHRISTENSEN