000 AXPZ20 KNHC 231522 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1310 UTC Thu May 23 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across Central America to a 1009 located over Nicaragua near 12N86W to 11N100W to 08N120W. The ITCZ continues from 08N120W to beyond 06N140W. Scattered moderate to strong convection is noted from 09.5N to 13.5N between 85W and 90W, and from 07N to 11N between 92W and 98W. Numerous moderate and scattered strong convection is seen from 08N to 13N between 98W and 102W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a ridge across the offshore forecast waters of Baja California and lower pressure over the SW CONUS and northern Mexico is supporting moderate to fresh NW winds off the west coast of Baja California and N of Punta Eugenia. NW swell associated with stronger winds off the coast of California continues to support seas of 8 to 13 ft north of Cabo San Lazaro, with the highest seas covering the waters N of 27N between 116W and 125W. Winds are forecast to diminish to a gentle to moderate breeze later today while seas will gradually subside to near 8 ft across the offshore waters W of 110W on Fri. Gulf of California: Winds have diminished across the northern Gulf this morning. Looking ahead, winds will increase again to 20 to 25 by Sat night ahead of a cold front approaching the region. Then, moderate to fresh SW winds will persist through Mon. Gulf of Tehuantepec: Fresh to strong northerly winds will pulse across the Gulf region early Sat morning, and again early Sun morning with the assistance of the nocturnal drainage flow. Seas will build to 8 ft with these short-lived gap wind events. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Disorganized showers and thunderstorms along portions of the west coast of Central America and the far eastern North Pacific are associated with a broad area of low pressure. Earlier satellite wind data indicated that the large circulation has moved inland over Central America and the chance for development has decreased. Regardless of development, locally heavy rains are likely to continue over portions of Central America as this system remains nearly stationary during the next few days. These rains could cause flash flooding and mudslides in areas of mountainous terrain. The Weather Service in Nicaragua has reported locally heavy rain during the las 24 hours ending at 7am this morning. Otherwise, the monsoon trough will dominate the regional pattern into early next week. Expect generally light to gentle winds north of the monsoon trough and moderate to fresh S to SW winds south of the monsoon trough through the weekend. Early next week, the global models suggest increasing winds south of the monsoon trough likely associated with a very broad area of low pressure over Central America and the SW Caribbean Sea. The increasing winds will depend on how the low pressure system described above evolves in the coming days. Seas generally will run 8 ft or less into the weekend, then build into early next week in response to the strengthening monsoon flow. This weather pattern is common in this area for this time of the year. REMAINDER OF THE AREA... Northwest swell over the waters north of 20N between 110W and 135W is producing seas ranging from 8 to 13 ft across the region with the highest seas N of 27N between 116W and 125W. This swell event will gradually decay by Fri, with seas falling below 8 ft Fri night into Sat. A high pressure ridge extends from a 1033 mb high near 37N139W east-southeastward to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ is maintaining fresh to locally strong trades over the waters west of 135W with seas up to 10 ft based on altimeter data. Elsewhere, a small area of 8 ft seas in SW swell persists roughly from 05N to 09N between 103W and 111W. Additional pulses of cross- equatorial SW swell will result in 8 ft seas developing over the waters S of 08N between 96W and 115W on Fri. Another and stronger SW swell event is expected early on Sun through early next week, reaching the coast of Mexico and Central America Mon night into Tue. $$ GR