000 AXPZ20 KNHC 082143 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Fri Jan 8 2021 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure has built across the eastern slopes of Mexico in the wake of a cold front in the Gulf of Mexico. The pressure gradient between this area of high pressure and the eastern north Pacific monsoon trough is supporting northerly gale force gap winds across the Gulf of Tehuantepec downstream to near 15N95W. Early afternoon ASCAT data showed minimal northerly gales across the Gulf. The gale force winds will continue through late Sat morning. Seas downwind of the Gulf of Tehuantepec will build to 10-13 ft through Sat. Winds and seas will diminish Sat night and Sun as high pressure north of the area weakens and the pressure gradient loosens. Looking ahead, another gale-force event is expected to start Mon and continue through early Fri. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N70W to 08.5N79W to 10N86W to 06.5N99W. The ITCZ continues from 06.5N100W to 05N119W to 07N127W to 05N140W. Scattered moderate convection is noted from 01.5N to 08N east of 83W, from 04.5N to 09N between 101W and 108W. Scattered moderate isolated strong convection is noted from 13.5N to 16N between 104W and 111W, and from 04.5N to 10N between 116W and 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features for details on the Gale Warning in the Gulf of Tehuantepec, as well as Gale Conditions Possible next week. Elsewhere, moderate to fresh NW to N winds are expected across the offshore waters of Baja California and north of Cabo San Lazaro over the next several days as a ridge remains in place just NW of the area. Large NW swell, with seas in the 8-11 ft range, dominates the waters west of Baja California, and will build to 8-13 ft by Sat morning. Additional pulses of large NW swell will continue to propagate across this region through next week. Gulf of California: Gentle to moderate NW to N winds are expected across the Gulf of California through Sat. Winds are forecast to increase Sat night into early Sun as high pressure builds over the Great Basin region of the United States. Winds in the northern and central Gulf are expected to become fresh to strong early Sun, then diminish to moderate to fresh through early next week. Peak seas are expected to build to around 6 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to fresh NE to E winds across the Gulf of Papagayo region will increase late tonight through early next week, pulsing to strong each night through the weekend. Elsewhere, light to gentle winds will prevail north of the monsoon trough. Gentle to moderate S to SW winds are expected south of the monsoon trough through Mon, except for moderate to briefly fresh northerly winds across the Gulf of Panama. Large seas generated by gale-force winds in the Tehuantepec region will reach the outer offshore waters of Guatemala and El Salvador today and Sat, and then again early next week. REMAINDER OF THE AREA... High pressure of 1030 mb is centered near 29N129W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh trade winds north of the ITCZ to 26N and west of 122W. Seas in this area are in the 8-13 ft range in a mix of NW swell and E-NE wind waves. These marine conditions will persist during the next few days. Long period NW swell continues to propagate across most of the forecast waters, with sea heights of 8-12 ft covering much of the waters west of 100W. New large NW swell propagated into the NW waters overnight, and is currently producing seas 12 ft and greater NW of a line from 30N125W to 15N140W, with seas in the 12 to 16 ft range. Another pulse of NW swell will move into the NW waters Sat, with seas peaking near 20 ft there Sat night. Yet another pulse of NW swell will enter the NW waters next Tuesday. $$ Stripling