000 AXPZ20 KNHC 181517 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Mar 18 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong high pressure building south through the western Gulf of Mexico will funnel winds across Mexico and into the Gulf of Tehuantepec today. This evening, these gap winds will increase to gale force, with gales persisting through Sun morning. Seas may reach 13-16 ft, especially Sat. Please read the latest NWS High Seas Forecast from the National Hurricane Center at the website: www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from 1010 mb low pressure over northern Colombia near 09N76W to 05N87W. The ITCZ continues from 05N87W to 02N108W to 03N120W to 04N140W. Scattered moderate and isolated strong convection is from 04N to 09N between 77W and 84W, from 00N to 05N between 100W and 109W, from 04N to 06N between 114W and 121W, and from 02N to 04N between 128W and 134W. Scattered moderate convection is noted from 00N to 02N between 79W and 83W, and from 06N to 08N between 122W and 129W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section above for details on a Gale Warning for the Gulf of Tehuantepec. Moderate NW to N winds over the waters north of 20N including the Gulf of California will prevail through the week along with seas of 5-7 ft. Mainly gentle winds are occurring off the west coast of mainland Mexico south of 20N, along with seas of 3-6 ft. A weakening cold front with increasing winds and a set of large NW swell will likely impact the waters west of Baja California this weekend into early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh NE to E winds are noted within and downstream of the Papagayo region. Light to gentle winds prevail elsewhere. Sea heights range from 3-6 ft. Fresh to strong NE to E winds will pulse across the Papagayo region through early next week. Seas associated with these winds will be 6-8 ft. Moderate to fresh winds will pulse over the Gulf of Panama this weekend into early next week. Light to gentle winds will continue to prevail elsewhere. Large seas from upcoming Gulf of Tehuantepec gap winds this weekend may spread into the offshore waters of Guatemala and El Salvador. REMAINDER OF THE AREA... Trade winds are moderate to fresh north of the ITCZ to 15N due to the pressure gradient between the ITCZ and the subtropical ridge. Seas are mainly 5-8 ft north of the ITCZ in old mixed swell and 5-7 ft south of the ITCZ. A cold front stretches from 30N130W to 24N140W. Deep convection near this boundary has diminished with scattered showers possible on either side of the front. Fresh S to SW winds are occurring north of 27N and ahead of the front, but these winds should diminish later today. The front will continue east across waters N of 20N through the end of the week, while slowly weakening. Moderate to fresh winds are expected behind the front. NW swell of 8-13 ft associated with the front will continue propagating south and east through the weekend. Winds will likely increase to fresh to strong during the weekend as strong high pressure north of the area settles south. $$ Lewitsky