000 AXPZ20 KNHC 090934 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 619 UTC Thu May 9 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Deepening low pressure over the lower Colorado River valley will support gap winds to gale force over the northern Gulf of California early Fri. Strong winds will linger over the northern Gulf of California Fri and Fri night near 30N, then gradually decrease over the northern Gulf as the ridge west of Baja California breaks down. Otherwise, light to moderate N to NW winds will prevail over the central and southern Gulf during the next several days, with daytime heating leading to onshore seabreezes along much of the coastline of mainland Mexico. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from low pres 1009 mb near 09N75W to 08N81W to 09N88W to 06N100W to 06N106W. The ITCZ continues from 06N106W to 06N120W to beyond 04N140W. Scattered moderate and isolated strong convection is noted from 04N to 09N E of 88W, from 02N to 04N between 100W and 103W and from 03N to 09N W of 108W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad ridge extends into the region from a 1033 mb high pressure centered well north of the area near 48N137W to 32N139W, then SE to S of Cabo Corrientes near 15N106W. The ridge is supporting moderate to fresh NW winds over open waters mainly north of 20N, with generally light to moderate NW winds farther south. Recent altimeter data indicated seas are generally 4 to 6 ft in open waters off Mexico. Surface observations still indicate smoke and haze are persisting over southern Mexico. However, low level winds are transporting the smoke northward toward the Gulf of Mexico. Accordingly, smoke from the ongoing fires is not expected to significantly affect visibility over the forecast waters during the next several days. Looking ahead, a cold front will move through Baja California and the northern Gulf of California late Fri and Sat. As described in the Special Features section above, deepening low pressure over lower Colorado River valley will support gap winds to gale force over the northern Gulf of California by early Fri. The front and low pressure will dissipate through Sat, but a broader low pressure area will persist off Baja California Norte through Sun. This will displace ridging farther south to along 20N. Long period SW swell will move into open waters starting Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fires over Central America continue to produce smoke. However, low level winds are transporting the smoke northward toward the western Caribbean and Gulf of Mexico. Accordingly, smoke from the ongoing fires is not expected to significantly affect visibility over the forecast waters. Scattered showers and thunderstorms are active south of 10N in the vicinity of the resident seasonal trough. An altimeter satellite pass from around 03Z shows seas of 3 to 5 ft in this area. Weakening high pressure north of the area will allow moderate NE to E winds over the Gulf of Papagayo to diminish by Fri morning. A significant S to SW swell event will move N from the Ecuador offshore waters and spread across the region Thu night through Sat night. Expect seas of 7 to 10 ft with peak periods around 20 seconds. This swell will produce dangerous surf conditions along the coast of Central America and northern South America through the end of this week. The large swell could produce areas of significant beach erosion and minor coastal flooding. REMAINDER OF THE AREA... A broad ridge extends SE into the region from a 1034 mb high pressure centered well N of the area near 48N137W to 32N139W, then SE to S of Cabo Corrientes near 15N106W. The ridge will weaken and be displaced S to near 20N in response to a broader area of low pressure residing W of Baja California Norte through Sun. A round of large long period S to SW swell is entering the far southern waters. The swell will steadily propagate N through this weekend. Seas will build to 12 ft south of the Equator between 95W and 110W today with 8 ft seas spreading as far north as 08N by Fri night. Most of the waters S of 20N and E of 125W will have combined seas of 8 ft or greater by Sun. Seas in this region will subside Mon and Tue as the long period swell decay. $$ CAM