000 AXPZ20 KNHC 180244 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI MAR 18 2016 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 0230 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 06N90W TO 06N97W TO 05N106W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... IN THE UPPER LEVELS...A RIDGE AXIS EXTENDS FROM 32N130W TO 24N136W TO 14N137W TO AN ANTICYCLONE AT 04N137W. BROAD HIGH PRES COVERS THE AREA S OF 25N W OF 100W. AN UPPER TROUGH IS OVER THE EASTERN PORTION OF THE DOMAIN N OF 11N BETWEEN 98W-111W. WATER VAPOR IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE COVERING JUST ABOUT THE ENTIRE DOMAIN EXCEPT OVER THE FAR EASTERN PORTION FROM 14N-19N AND E OF 109W WHERE SCATTERED TO BROKEN HIGH CLOUDS ARE SEEN STREAMING NEWD TOWARDS CENTRAL MEXICO...AND WELL INLAND MEXICO AND E FROM THERE COVER MUCH OF THE GULF OF MEXICO. AT THE SURFACE...A 1019 MB HIGH IS ANALYZED AT 27N132W WITH A RIDGE SE TO NEAR 19N118W. HIGH PRES COVERS THE AREA N OF 15N W OF 115W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ AXIS IS SUPPORTING MODERATE NE TRADE WINDS FROM 05N TO 15N W OF 124W WITH SEAS OF 6-8 FT. A COLD FRONT HAS MOVED INTO THE FAR NW CORNER OF THE AREA ALONG A POSITION FROM 32N136W TO 26N140W. THE LEADING EDGE OF THE FRONT IS CLEARLY DEFINED ON LAST FEW VIS IMAGERY BY A ROPE CLOUD FEATURE. SCATTERED SHOWERS ARE POSSIBLE WITHIN ALONG THE FRONT. AN ASCAT PASS FROM 1834 UTC THU DISPLAYED MODERATE TO FRESH S-SW WINDS WITHIN ABOUT 90 NM SE OF THE FRONT. THE SAME ASCAT PASS SHOWED GENTLE TO MODERATE NW-N WINDS BEHIND THE FRONT. THE FRONT IS FORECAST TO WEAKEN AS IT REACHES A POSITION FROM NEAR 32N132W TO 27N137W TO 26N140W BY LATE TONIGHT. THE MAIN ISSUE...AS STATED PREVIOUSLY...WILL BE LARGE LONG PERIOD NW SWELL PROPAGATING THROUGH THE NW WATERS WHERE MAX SEAS ARE EXPECT TO REACH UP 12 FT. THE FRONT WILL TRANSITION TO A WEAKENING STATIONARY FRONT AS IT REACHES FROM NEAR 32N132W TO 27N137W TO 26N140W EARLY FRI EVENING WITH THE LARGE NW SWELL IN ITS WAKE FURTHER INCREASING THE SEAS TO 13 FT. THE SWELL IS FORECAST TO OUT RUN THE WEAKENING FRONT AT THAT TIME REACHING TO A LINE FROM 32N131W TO 25N136W TO 20N140W WITH SEAS UP TO 12 FT. MOISTURE CONVERGENCE GUIDANCE FROM THE GFS MODEL SUGGESTS THAT BY EARLY ON SAT AFTERNOON THE FRONT WILL BE DISSIPATING STATIONARY AS IT MERGES WITH A PRE-FRONTAL TROUGH ALONG A POSITION FROM NEAR 32N134W TO 26N140W. THE NW SWELL WILL CONTINUE W OF THIS BOUNDARY AT THAT TIME INDUCING SEAS UP TO 12 FT. ALSO BY EARLY SAT AFTERNOON...SEAS IN THE RANGE OF 8-11 FT ARE FORECAST TO BE ELSEWHERE W OF A LINE FROM 32N121W TO 20N129W TO 07N140W AS A NEW COLD FRONT APPROACHES THE FAR NW CORNER. BY SAT EVENING... THE TROUGH WILL EXTEND FROM NEAR 32N133W TO 25N140W AS A NEW COLD FRONT MOVES INTO THE FAR NW CORNER OF THE AREA. SEAS OF 10- 12 FT ARE FORECAST TO BE W OF THE FRONT WHILE SEAS IN THE RANGE OF 8-12 FT ARE EXPECTED ELSEWHERE W OF A LINE FROM 32N120W TO 20N128W TO 06N140W. BEYOND 48 HOURS...A RELATIVELY STRONG COLD FRONT IS FORECAST TO MOVE SE ACROSS THE GULF OF MEXICO AND REACH THE CHIVELA PASS ON SUN. THE BUILDING HIGH PRES BEHIND THE FRONT WILL INDUCE A GULF OF TEHUANTEPEC GAP WIND EVENT. CURRENTLY...GALE CONDITIONS ARE FORECAST FROM SUN NIGHT THROUGH TUE MORNING...WITH PEAK SUSTAINED WINDS FORECAST TO REACH 40 KT WITH POSSIBLE HIGHER GUSTS DURING THIS EVENT. LATEST WAVEWATCH GUIDANCE INDICATES THAT WAVE HEIGHTS MAY REACH RATHER HIGH HEIGHTS WITH A RANGE FROM ABOUT 13-19 FT SUN NIGHT INTO MON AFTERNOON IN THE GULF. THE WAVEWATCH GUIDANCE ALSO DEPICTS LARGE SEAS...IN THE RANGE OF 9-14 FT...TO SPREAD SW FROM THE GULF OF TEHUANTEPEC REGION REACHING TO NEAR 09N100W ON MON. A GULF OF PAPAGAYO GAP WIND EVENT WITH NE 20-25 KT WINDS IS SUGGESTED BY MODEL GUIDANCE TO BRIEFLY TAKE PLACE EARLY ON MON. $$ AGUIRRE