000 AXPZ20 KNHC 162036 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Oct 16 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 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure is building across the Gulf of Mexico as a cold front pushes across the basin. This is supporting strong near gale gap winds across the Gulf of Tehuantepec. These winds will increase to gale force early this evening and pulse through Mon morning. Seas are expected to build to 8 to 12 ft downwind of the gale force winds. Please see the latest High Seas Forecast at http://nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...TROPICAL WAVES... A tropical wave is along 84W through western Panama and eastern Costa Rica, moving W at 10 to 15 kt. Scattered moderate to isolated strong convection is observed north of 05N east of 85W. A tropical wave is along 96W and between 02N and 15N, moving W at 10 to 15 kt. Scattered moderate convection are noted from 09N to 12N between 94W and 98W. A tropical wave is along 112W from 03N to 15N, moving W at around 10 to 15 kt. Scattered moderate to isolated strong convection is noted from 07N to 13N between 107W and 116W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Nicaragua near 11N85W to 10N110W to 13N125W to beyond 12N140W. Aside from the convection associated with the tropical waves discussed in the section above, scattered moderate convection is noted north of 08N between 78W and 80W in the Gulf of Panama, and from 08N to 10N between 100W and 107W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section for more information on the gale warning in the Gulf of Tehuantepec. A scatterometer satellite pass from earlier today confirmed fresh to strong NW winds over the northern Gulf of California. This was due to fairly strong high pressure north of the area over the Great Basin tightening the pressure gradient over the region. The winds and seas have subsided since then as the high pressure north of the area weakens and shifts farther to the east. Elsewhere over Mexican offshore waters, a ridge extends from 1021 mb high pressure near 35N134W to south of Cabo San Lucas, supporting mostly gentle to moderate NW breezes north of 20N, with 4 to 6 ft seas in a mix of NW and SW swell. Light breezes persist south of 20N outside of the Gulf of Tehuantepec, with 3 to 5 ft seas in SW swell. For the forecast, winds and seas will continue to diminish across the northern Gulf of California this afternoon, as winds increase over the Gulf of Tehuantepec. Little change elsewhere into mid week. Looking ahead, seas will build off Baja California north of Cabo San Lazaro as NW swell moves into the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Light N winds prevail north of the monsoon trough with gentle to moderate SW winds ongoing to the south. Scattered moderate to isolated strong convection continues in the Gulf of Panama and off western Panama. Recent altimeter passes confirm seas are 5 to 7 ft, and this is mainly due to SW swell. For the forecast, seas off western Guatemala beyond 120 nm may be 6 to 8 ft into Mon in a mix of N swell from the Tehuantepec region and longer period SW swell. Elsewhere seas will average about 4 to 6 ft in SW swell. Fresh to locally strong winds are expected to pulse in the Gulf of Papagayo Mon night an Tue. Scattered thunderstorms are expected to continue across the region through early next week. REMAINDER OF THE AREA... Moderate to locally fresh NE winds prevail over areas north of the monsoon trough and west of 120W, with gentle to moderate winds south of the monsoon trough. Recent altimeter satellite data showed seas approaching 8 ft north of 29N between 125W and 130W. This is in mainly NW swell, and is subsiding below 8 ft currently. Another area of 8 to 9 ft swell from 04N to 07N between 110W and 115W will also subside through late today. Elsewhere, moderate winds and seas in the 5 to 7 ft range will prevail into early next week. NW swell to 8 ft will move into the waters north of 27N between 120W and 130W Tue into Wed then subside. Looking ahead, another more substantive area of NW swell will accompany a cold front move into the waters north of 28N and west of 130W Tue night, with seas in excess of 8 ft dominating the waters northwest of a line from Guadalupe Island to 17N140W by late Thu. $$ Christensen