000 AXPZ20 KNHC 152052 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2052 UTC Wed May 15 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08.5N83W to 1011 mb low pressure near 09N100W to 05N115W. The intertropical convergence zone from 05N115W to 06N140W. Scattered moderate to isolated strong convection is observed from 05N to 11N between 90W and 93W, and from 04N to 10N between 95W and 105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Several ship observations off the coast of Baja California south of Punta Eugenia indicate 10 to 15 kt NW winds. The ships and a concurrent altimeter pass show seas 4 to 6 ft in the same area. The NW winds are on the eastern edge of 1018 mb high pressure centered near 24N122W. The high will weaken through tonight ahead of a cold front advancing from the west. Farther south, satellite imagery shows areas of smoke off the Mexican coast between Manzanillo and the Gulf of Tehuantepec. For tonight, a mid to upper trough moving across southern California will allow a trough over the lower Colorado River Valley will deepen through the evening. This will allow fresh to strong winds into the northern Gulf of California overnight. The front will move across Baja California Norte Thu then stall across the central Gulf of California and Baja California Sur late Thu through Fri, followed by NW swell off Baja California Norte. Winds and seas diminish Sun as high pressure builds over the region. Looking ahead, another front will move through the region Sun night and Mon. Today is the first day of the Eastern North Pacific Hurricane Season. No tropical cyclone activity is expected for the next several days in the Mexican Offshore Waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern will maintain generally quiet wind conditions across the region through the forecast period, with generally onshore wind flow expected from the Papagayo region eastward through Fri night. Long period southwest swell will build seas to 8 ft west of Ecuador beginning on Fri night through early next week. Agricultural fires continue over northern Central America. However, the low-level southerly flow is generally keeping the associated smoke over land and no significant impact on visibility is occurring over the offshore waters at this time. REMAINDER OF THE AREA... A scatterometer pass from 18 UTC showed the position of a cold front reaching from 30N130W to beyond 26N140W. Scatterometer and altimeter satellite passes show moderate winds and seas less than 8 ft south of 30N near the front. The front is moving eastward across the waters north of 20N, disrupting the standard subtropical ridge over the area. This is maintaining fairly light trade winds farther south into the deep tropics. High pressure will build over the waters north of 25N through Fri, allowing trade winds farther south to increase to 15 to 20 kt west of 130W. Northerly swell in excess of 8 ft will also follow the front over waters north of 25N east of 120W Thu into Fri. The high pressure will drift east Sat and Sun ahead of another cold front entering the region from the northwest late Sat. This second front will move across the waters north of 20N through early next week, followed by long period NW swell of 8 to 9 ft. Looking ahead, high pressure will follow the second front Sun into Mon, supporting fresh trades farther south into the tropics. Seas will build to 8 ft from 10N to 20N west of 135W in mixed NW swell and shorter period NE wind waves. $$ Christensen