000 AXPZ20 KNHC 100820 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 503 UTC Sun May 10 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... A Gale Warning has been issued for the Gulf of Tehuantepec. High pressure building across the eastern slopes of the Sierra Madre Mountains in Mexico will promote a late season Gulf of Tehuantepec event. Climatologically, the final gale-force event occurs in the Gulf in late March or early April. Only a couple of Tehunatepec events have been detected in May since the 1999-2000 season, one in 2003, and the second one in 2006. This Tehuantepec event will begin early this morning, reaching minimal gale force tonight. Expect fresh to strong northerly winds downwind of the Gulf to near 11N by Mon morning, with seas building to 12 or 13 ft. Winds will diminish below gale force by early afternoon on Mon, but the gap wind event will continue through Tue morning. Frequent gusts to gale force are possible Mon night. Please, see latest NWS High Seas Forecast issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1010 mb low pressure over northern Colombia to 09N84W to 07N101W. The ITCZ continues from 07N101W to 07N120W to beyond 08N140W. Scattered moderate to strong convection is noted from 04N to 09W between 100W and 111W. Isolated moderate to strong convection is seen from 04N to 10N between 92W and 100W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore forecast waters W of Baja California producing gentle to moderate NW-N winds, with seas of 5-7 ft in southerly swell. Little change in this weather pattern is expected over the next several days. Seas of 8 ft in SW swell are noted between the Revillagigedo and Clarion Islands per altimeter data. Seas will subside to less than 8 ft today. Gentle to moderate southerly winds will prevail across the Gulf of California. On Thu, building high pressure over the Pacific may strengthen NW winds west of Baja California. Long period SW swell will continue to impact the offshore waters of Mexico through Monday. Another long period SW swell event is forecast to reach the coast of Mexico between the Tehuantepec region and Cabo Corrientes on Thu. Haze and areas of smoke from agricultural fires in Mexico may reduce visibilities near the coast from the Tehuantepec region to near Cabo Corrientes. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong winds are expected in the Papagayo region by Mon night as high pressure builds N of area. Elsewhere, a weak pressure gradient will support light to gentle winds during the next several days. Large, long period SW swell will continue to impact the offshore waters of Central America, Colombia and Ecuador today before gradually fading. REMAINDER OF THE AREA... A weak 1019 mb high pressure located near 32N130W extends a ridge across the north waters to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is causing moderate trade winds W of 115W. Long period SW swell will continue to impact roughly the waters from 02N to 14N between 90W and 115W, and from 15N to 20N between 103W and 110W, including near cabo Corrientes. Peak seas are 8 to 10 ft in this area per altimeter data. A weak cold front currently located near 30N140W will move across the NW waters through late Mon while weakening. A set of long period NW swell will follow the front, building seas to 8-10 ft. These seas will propagate across the waters NW of a line from 30N130W to 25N140W by Mon night, subsiding to less than 8 ft on Tue. $$ GR