000 AXPZ20 KNHC 180846 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Dec 18 2020 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 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehunatepec Gale Warning: High pressure over the Gulf of Mexico behind a stationary front is producing gale-force winds over the Gulf of Tehuantepec this evening and through Friday afternoon. Ship 9HA3851 reported 40 kt winds as well as 17 ft seas while in the Gulf of Tehuantepec at 0600 UTC. Winds are expected to diminish in the Gulf of Tehuantepec below gale force by this afternoon. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W TO 07N94W. ITCZ begins 07N94W and extends to beyond 07N140W. Scattered moderate and isolated strong is located from 07N TO 12N, west of 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features for details about the Gulf of Tehuantepec Gale Warning. While the gale over the Gulf of Tehuantepec should end by tonight, the gap winds will continue with fresh to strong N winds through Sun. A new cold front to move across the Gulf of Mexico Sun and Mon may force additional N gales over the Gulf of Tehuantepec Mon afternoon through Tue morning. Peak seas anticipated with this second gale event may reach around 15 ft Mon evening and Tue. Large, long period NW swell west of Baja California will slowly subside through Sun. Gulf of California: A weakening cold front will push across the Baja peninsula into the Gulf of California today. NW winds will build up to strong breeze across the Gulf of California Sat and Sun. Seas should peak around 6-8 ft in the central Gulf of California on Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to occasionally strong NE to E winds will pulse across the Papagayo region during the next several days as high pressure remains in place over the W Caribbean. Seas offshore of Guatemala and El Salvador will increase to 6-8 ft through Fri night from swell generated by gale-force winds over the Gulf of Tehuantepec. Seas will again increase to 8-10 ft on Tue from a new Gulf of Tehuantepec gale event. REMAINDER OF THE AREA... A 1030 mb high is centered near 37N133W with surface ridging extending southeastward to 12N110W. The moderate pressure gradient between the high the the ITCZ is causing E to NE trades of up to fresh breeze. The high will strengthen some through Sat and increasing the trades to a large area of fresh to strong. Seas will peak around 8-10 ft on today and Sat due to combined wind waves and some NW swell. A cold front impinging on the high will allow the trades to weaken substantially Sun through at least Tue. No new large long-period swell is expected over forecast waters for the next several days. $$ Landsea