000 AXPZ20 KNHC 180353 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Oct 18 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 0000 UTC surface analysis and satellite imagery through 0350 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure continues to build across the Gulf of Mexico behind a cold front that extends from Naples, Florida to the eastern Bay of Campeche. Fresh to gale force winds in the Bay of Campeche continue to funnel across the Chivela Pass tonight, thus supporting northerly winds of the same magnitude in the Tehuantepec region. Seas with these winds range between 8 to 12 ft. The front will move east of the Gulf of Mexico by Mon morning. This will result in a weaker pressure gradient and winds diminishing below gale force in Tehuantepec. Please see the latest High Seas Forecast at http://nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...TROPICAL WAVES... A tropical wave extends north of 01N to western Honduras with axis near 88W, moving westward at 10-15 kt. There is no significant convection associated with this wave. A tropical wave extends from 03N to 16N with axis near 102W, moving westward at 10-15 kt. Scattered moderate convection is from 06N to 17N between 94W and 100W. A tropical wave extends from 03N to 16N with axis near 119W, moving westward at 15 kt. Scattered moderate convection is from 07N to 10N between 110W and 118W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N79W to 10N102W to a 1011 mb low near 10N121W to 11N140W. Aside from the convection associated with the tropical waves discussed in the section above, scattered moderate convection is from 06N to 12N between 120W and 127W, and from 07N to 16N west of 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section above for more information on the ongoing Gale Warning for the Gulf of Tehuantepec. A weak pressure gradient across the region is maintaining gentle to locally moderate NW winds over the Baja California peninsula offshore waters and light to gentle variable winds across the southern half of the Gulf of California and the SW Mexico offshore waters outside of the Tehuantepec area. Seas are 3 to 5 ft due to mixed NW and SW swell. Over the northern Gulf of California, a surface trough is supporting fresh to strong SW winds with seas to 4 ft. Otherwise, showers and tstms are across the offshore waters of Oaxaca and Chiapas associated with the passage of a tropical wave. For the forecast, gentle to moderate winds will persist into mid week and the swell will subisde by Tue. By Tue night, NW long period swell will start to move into the waters off Baja California Norte, building seas of 5 to 7 ft through Thu and to 9 ft Fri and Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Light to gentle north winds prevail north of the monsoon trough, while gentle to moderate southwest winds are to its south. Seas across the region are in the 4-5 ft range. Otherwise, scattered showers and isolated thunderstorms are noted in the offshore waters of Costa Rica and Nicaragua. For the forecast, seas off western Guatemala beyond 120 nm may peak to 8 ft into Mon in a mix of N swell from the Tehuantepec region and longer-period SW swell. A broad area of low pressure is expected to form around the middle of the week a couple of hundred miles south of the coast of southern Mexico. Some slow development of this system is possible thereafter as it moves west-northwestward off the coast of Mexico. REMAINDER OF THE AREA... Moderate to locally fresh northeast winds continue over the waters north of the monsoon trough and west of 120W, with gentle to moderate winds south of the monsoon trough. Gentle to moderate north to northeast winds and seas in the 5-7 ft range will change little into the early part of the upcoming week. A NW swell expected to raise seas to 8 ft will move into the waters north of 27N between 120W- 130W Tue into Wed, then subside. Looking ahead, another round of NW swell will accompany a cold front that will move into the waters N of 28N and W of 130W Tue night, with seas in excess of 8 ft dominating the waters NW of a line from Guadalupe Island to 14N140W by late Thu. $$ Ramos