000 AXPZ20 KNHC 161557 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure will build across the Gulf of Mexico as a cold front pushes across the basin. This will bring fresh to strong northerly winds beginning early this morning across the Gulf of Tehuantepec. Winds will increase to gale force early this evening and pulse through Mon morning. Seas are expected to build to 8 to 11 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 83W through western Panama and eastern Costa Rica, moving W at 10 to 15 kt. Scattered moderate convection is observed north of 05N between 81W and 85W. A tropical wave is along 94W and N of 02N, moving W at 10 to 15 kt. Scattered showers and thunderstorms are noted from 09N to 12N between 94W and 97W. Another tropical wave extends its axis along 111W from 03N to 16N, moving W at around 10 to 15 kt. Scattered moderate convection is noted from 06N to 13N between 108W and 114W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Nicaragua near 12N86W to 13N95W to 10N108W 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. Fairly strong high pressure north of the area over the Great Basin has been supporting fresh to strong NW winds across mainly the northern Gulf of California since last night. An earlier scatterometer satellite pass from showed this. And an altimeter satellite pass from 0900Z showed seas to 6 ft over the northern Gulf of California as well. The winds and seas are probably subsiding currently 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 today, as winds increase over the Gulf of Tehuantepec. Little change elsewhere through mid week. 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 thunderstorms are moving along the coasts of Nicaragua southward to Panama. Meanwhile, scattered moderate to isolated strong convection is noted 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, fresh to locally strong winds are expected to pulse in the Gulf of Papagayo Mon night. Scattered thunderstorms are expected to continue across the region through Sun night. 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 will subside below 8 ft later today. Another area of 8 to 9 ft swell from 04N to 07N between 109W and 116W will also subside through late today. Elsewhere, moderate winds and seas in the 5 to 7 ft range will prevail. $$ Christensen