000 AXPZ20 KNHC 282143 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Oct 28 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 2030 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...Strong high pressure will build across the western Gulf of Mexico behind a cold front late tonight through Thursday, as Hurricane Zeta exits the basin to the north. This will induce strong northerly gap winds through the Chivela pass and across the Gulf of Tehuantepec late on Thu. Computer model guidance suggests a rapid wind increase to near gale force winds late Thu afternoon through around sunset, increasing to 40 kt overnight, with gales continuing into Sat morning. Strong gap winds will persist Saturday, with gales returning Sun morning. Peak seas during the high wind event are expected to build to around 16 ft Fri afternoon. ...TROPICAL WAVES... There are presently no identifiable tropical waves analyzed across the eastern Pacific Ocean. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N75W to 09N79W to 12N93W to 10.5N105W to low pres 1010 mb near 11N119W to 10N128W to 12N140W. Scattered moderate to strong convection is noted from 03.5N to 11.5N E of 88W, and from 08N to 12N between 115W and 132W. Scattered moderate isolated strong convection is noted from 09N to 15.5N between 92W and 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front has dissipated today from near Mazatlan, Mexico southwestward across the entrance to the Gulf of California. Early afternoon scatterometer data showed fresh northerly winds in the Gulf of California extending from the Tiburon Basin southward to beyond Las Tres Marias to 20N and the waters offshore of Cabo Corrientes. Seas between Las Tres Marias and Cabo San Lucas were around 8 ft through mid morning, and are still likely around 7 ft, while seas of 4-6 ft prevail across the southern Gulf. Elsewhere, moderate to locally fresh N to NE winds prevail west of Baja California where seas are 5 to 7 ft. Wind are expected in increase slightly to around 20 kt across central portions of the Gulf this evening before diminishing late tonight, while winds and seas diminish across the entire region Thu as high pressure to the NW drifts further NW. Winds will remain light to gentle over the SW Mexico offshore waters south of 19N, except for the offshore waters between Puerto Vallarta and Manzanillo, where moderate to fresh NW winds are expected through Thu evening. Gentle to moderate winds are expected area wide through the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate south to southwest winds will prevail south of the monsoon trough and 09N through Sun. Seas are presently in the 5-7 ft range and are expected to increase west of Guatemala and El Salvador Fri through the weekend due to gale force winds in the Gulf of Tehuantepec pushing northerly waves into the area. Moderate to fresh offshore gap winds are expected across the Papagayo region Sat night. Very active convection continues this afternoon across the waters north of 04N from the Papagayo region east and southeastward across Central America and into coastal Colombia. Ample moisture persists across this region between the exiting Zeta in the northern Gulf of Mexico and an approaching tropical wave in the central Caribbean Sea. Look for this active weather to continue through Thu night before shifting offshore. REMAINDER OF THE AREA... High pressure offshore of Northern California extends a broad ridge southward into the northern forecast waters generally west of 120W. The pressure gradient between the ridge and lower pressures associated with the monsoon trough will support moderate to fresh NE trade winds over an area roughly from 12N to 23N, west of 115W, for the next several days. Recent altimeter data indicated seas are mainly 6 to 8 ft across this region in a mix of swell and easterly wind waves. Little change is expected in these conditions before seas subside very slightly Thu through Fri. South of the monsoon trough, a moderate to locally fresh S to SW winds prevail between 100W and 130W. Winds south of the trough between 115W and 130W are expected to increase slightly this evening through Thu afternoon and will raise seas to around 8 ft there. $$ Stripling