000 AXPZ20 KNHC 240228 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0228 UTC Fri May 24 2019 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 0000 UTC surface analysis and satellite imagery through 0210 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1009 mb low pressure near 11N86W to 10N100W to 07N115W to 07N120W. The ITCZ continues from 07N120W to 08N125W to beyond 06N140W. Scattered moderate and isolated strong convection is noted within 180 nm of the monsoon trough east of 88W, within 180 nm of the monsoon trough between 95W and 105W, and within 60 nm of the ITCZ west of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh NW winds likely persist near the west coast of Baja California between a high pressure ridge across the Baja California offshore waters and lower pressure over northern Mexico. Winds are expected to diminish later tonight into Fri as the pressure gradient relaxes over the region. While earlier altimeter data supported seas to 12 ft near the outer waters west of Guadalupe Island, max wave heights are likely closer to 10 ft this evening as the NW swell is slowly decaying. Seas will subside to 8 ft or less by Fri night. Looking ahead, seas will build to 8-9 ft off Baja California early next week in mixed SW and NW swell. Gulf of California: Gentle to moderate breezes will prevail across the Gulf of California through Sat. By Sat night, SW gap winds will strengthen across the northern Gulf ahead of a cold front approaching the region. Expect strong to near gale force gap winds north of 29.5N Sat night into Sun with strong winds persisting through Sun night. Wind speeds will diminish by early next week. Gulf of Tehuantepec: Fresh to strong northerly winds will pulse across the Gulf of Tehuantepec region during the overnight and early morning hours this weekend with the assistance of the nocturnal drainage flow. Seas will build to 8-9 ft with these short-lived gap wind events. Fresh northerly winds early Mon will diminish through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A broad area of low pressure centered near the west coast of Nicaragua is producing disorganized showers and thunderstorms over portions of Central America and the adjacent waters of the eastern North Pacific. Any development of this system during the next few days should be slow to occur while the large circulation interacts with land. Regardless of development, locally heavy rains are likely to continue over portions of Central America as this system remains nearly stationary through the weekend. These rains could cause flash flooding and mudslides in areas of mountainous terrain. The monsoon trough will dominate the regional pattern through early next week. Winds south of the monsoon trough will likely strengthen Mon through Tue, although wind speeds will be highly dependent on how the broad low pressure system over Central America evolves over the next few days. Seas will generally remain 8 ft or less through the weekend, then build to 8-10 ft early next week as SW swell mixes with locally generated wind waves due to strengthening monsoon flow. REMAINDER OF THE AREA... The northwest swell impacting the waters north of 20N between Baja California and 133W is beginning to decay this evening. Recent altimeter data indicates seas are running 8-11 ft with the highest waves near 30N. This swell will continue decaying through Fri with seas falling below 8 ft late Fri night. A high pressure ridge extends from a 1033 mb high near 36N141W southeastward toward the Revillagigedo Islands. The pressure gradient between this ridge and lower pressure near the ITCZ is maintaining fresh to strong NE trades over the waters west of 135W. Seas of 8-10 ft in this region will gradually subside through Sat as wind speeds diminish in response to the ridge weakening. Elsewhere, a small area of 8 ft combined seas in SW swell and local wind waves likely exists south of the monsoon trough between 93W and 97W. Seas in this region will subside overnight. South of the Equator, SW swell is producing 8 ft seas over the waters roughly west of 105W. This swell will continue spreading northward through at least Fri night. A stronger SW swell event will begin over the southern forecast waters Sun and propagate northward through early next week. This will result in a large area of 8 ft or greater seas south of 10N between 95W and 125W Mon and Tue as SW swell mixes with wind waves generated by the monsoon circulation. $$ Reinhart