000 AXPZ20 KNHC 071935 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Dec 7 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 1800 UTC surface analysis and satellite imagery through 1930 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure has built along the eastern slopes of the Sierra Madre in eastern Mexico in the wake of a cold front moving across the Gulf of Mexico. The pressure gradient between this area of high pressure and the eastern north Pacific monsoon trough is supporting gale force winds in the Gulf of Tehuantepec. Winds are forecast to increase, and reach in excess of 40 kt tonight. Winds are forecast to remain in the 40 kt range through early Wed before diminishing below gale force Wed night. Seas are forecast to peak near 16-18 ft during the period of strongest winds tonight. Swell from these gales will spread well away from the Tehuantepec region, with seas 8 ft or greater reaching as far west as 110W by Wed. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.html for more details. Of note: Based on the last 20 years, 329 gale and 106 storm- force gap wind events have been observed in the Tehuantepec region, an average of 16 gale and 5 storm events per cold season. The average starting date for Tehuantepec gale events is around October 25th, and the average date of the last event is around April 9th. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N80W to low pressure near 08N99W to 12N116W to 08N125W. The ITCZ continues from 08N125W to beyond 07N140W. Scattered moderate convection is noted from 05N to 10N between 81W and 100W, from 11N to 16N between 106W and 121W, and from 05N to 10N W of 127W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more on the Gulf of Tehuantepec gale force gap wind. Elsewhere, gentle to moderate winds prevail, with seas in the 5-7 ft range over the open waters, and 2-4 ft over the Gulf of California. NW swell has entered the waters west of Baja California today, and seas will peak near 14 or 15 ft N of Punta Eugenia Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh NE to E winds will increase to fresh to strong tonight through Fri as high pressure builds over the western Caribbean. Winds may reach near gale- force Wed. Seas will build to near 10-11 ft Thu, with seas greater than 8 ft extending well downwind of the Papagayo region by the end of the week. Elsewhwere, gentle to moderate S to SW winds will prevail south of the monsoon trough through the next several days. Swell generated in the Tehuantepec region will propagate over the waters off Guatemala and El Salvador tonight, building seas of up to 10 ft through the middle of the week. Seas in the 4-6 ft range will prevail elsewhere. REMAINDER OF THE AREA... The pressure gradient between high pressure north of the area and lower pressure in the vicinity of the ITCZ, and within the monsoon trough, is supporting an area of moderate to fresh trade winds roughly from 10N to 20N west of 120W. Seas are 7 to 9 ft in subsiding NW swell and NE wind waves across this area. A ridge will persist across the northern forecast waters over the next several days, keeping a large area of moderate to fresh trade winds. Low pressure will develop well W of Baja California Tue, and this may bring a period of strong N winds Tue and Wed N of 25N between 120W and 130W. Subsiding NW swell prevails across most of the waters N of the equator and W of 110W, with seas of 6-9 ft. Another set of long period NW swell propagating over the NW corner of the forecast region will spread SE across the forecast waters. This swell will bring seas greater than 12 ft over much of the waters north of 20N Tue, and peak near 15-17 ft before starting to subside. Seas greater than 8 ft with this swell will cover much of the waters west of 105W by Wed night. $$ KONARIK