000 AXPZ20 KNHC 130929 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Dec 13 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0850 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong surface high pressure resides across eastern Mexico tonight, in the wake of a stalled frontal boundary across the western Gulf of Mexico. This pattern is supporting gale force gap winds across the Tehuantepec region. Strong to gale force N-NE winds continue across the Gulf of Tehuantepec and extend downwind to near 13N97W, with seas of 8 to 11 ft. Gale force winds are expected to continue through sunrise this morning, with seas building to 12 ft. Winds will then diminish slightly with strong to near gale force N-NE winds continuing across the Tehuantepec region and downstream waters Mon afternoon through Wed morning, then diminish to fresh to strong through Fri. Please refer to the latest High Seas Forecast product issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W to 09.5N86W to 06.5N94W. The ITCZ extends from 06.5N94W to 07N106W to 06N111W to 08N126W to beyond 07N140W. Scattered moderate convection is from 05.5N to 11N E of 89W, from 10N to 12.5N between 96W and 102W, and from 07.5N to 13N between 122W and 140W. Scattered moderate to strong convection is from 15N to 21N between 120W and 125W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO See the Special Features section above for details on the current gale force gap wind event in the Tehuantepec region. Weak 1020 mb high pressure is centered just W of the Baja California offshore waters near 25N121W. This is promoting light to gentle northerly winds tonight across the Baja California offshores, the Gulf of California through the entrance of the Gulf. Seas are 2-4 ft through the Gulf of California and 4-6 ft in NW swell across the offshore waters of Baja. In Tehuantepec, strong to gale force winds are ongoing with 8-11 ft seas. Looking ahead, a strong cold front will move into the northern waters Tue. Fresh to strong SW winds are expected ahead of the front across the offshore waters N of 27N Tue afternoon before the front arrives Tue evening. NW swell will move into the northern offshore waters early Tue and raise seas 8 to 13 ft by Tue afternoon, and peak at 10-15 ft across the waters of Baja Norte Wed morning. Meanwhile, similar strong SW to W gap winds will develop inside the N Gulf of California Tue and reach around 30 kt Tue evening, when seas will build to 9 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh to strong NE to E continue across the Papagayo region with seas to 7 ft. These gap winds are forecast to continue through Wed, and then diminish to moderate to fresh through Fri. Peak seas are forecast to be 6-7 ft. Gentle to moderate northerly winds and seas to 4 ft in the Gulf of Panama are forecast through Wed. Moderate S to SW winds are south of the monsoon trough with seas to 6 ft in SW swell. Light to gentle variable winds are elsewhere. These conditions are forecast to remain for the next several days. REMAINDER OF THE AREA... A weakening high pressure ridge prevails across the forecast waters N of 15N between 108W and 135W, centered on a 1020 mb high near 25N121W. A pair of troughs are to the south of the ridge, with the resultant pressure gradient producing a zone of fresh E winds from 16-24N between 120W and 134W. A strong cold front is moving across the far NW waters, extending from 30N133W to 27N140W. This front is forecast to continue moving E-SE through early next week, accompanied by very large NW swell. Seas are currently 8-13 ft behind the front. Elsewhere mainly gentle to moderate NE to E winds are N of 24N with seas to 6 ft in NW swell. Moderate to fresh SE winds are S of the ITCZ W of 118W with seas 6 to 7 ft. Large NW swell will continue to build across the NW waters tonight and move east of 120W Tue afternoon. Seas are expected to peak at 18-19 ft across the far NW waters Tue morning, with seas remaining 12 ft and greater N of 17N and W of 120W through late Wed. $$ Stripling