788 AXPZ20 KNHC 072211 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue May 7 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... A trough axis extends from 10N75W TO 06.5N81W TO 08.5N90W TO 08N101W, where it transitions to ITCZ, continuing on to 08.5N118W to beyond 06N140W. Numerous moderate scattered strong convection is observed from 07N to 11N E of 93W and within 270 nm S of the trough between 93W and 98W. Scattered moderate to strong convection is present from 03.5N to 10N W of 113W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure continues to build SE into the region this afternoon, with a ridge extending from near 32N132W across the Baja California offshore waters to the waters S of Cabo Corrientes near 15N105W. Generally moderate to locally fresh NW winds persist off the coast of Baja California between the ridge and lower pressure over the Gulf of California. Fresh to strong NW winds will develop this evening through early Wed along the coast and just downstream of Cabo Corrientes as the ridge persists offshore and low pressure deepens over interior Mexico. Combined seas will build to 8 ft in mixed S swell and N wind waves. Elsewhere, moderate to occasionally fresh NW flow will prevail over the Baja California offshore waters through Thu with seas generally 5-7 ft. Looking ahead, low pressure will develop off the southern California coast Fri and weaken the ridge into the weekend. This will allow winds off Baja California to diminish to gentle with gradually subsiding seas into the weekend. Gentle manly westerly winds will prevail across the remaining Mexican waters east of Manzanillo for the next several days, where seas currently near 5 ft will build to 6-8 ft Fri through Sat as long period S to SW swell moves into the region. Ongoing agricultural burning in southeast Mexico continues to produce smoke across the region and may occasionally reduce visibilities over the adjacent offshore waters. Gulf of California: SW to W gap winds over the northern Gulf have diminished to around 15 kt or less this afternoon. A cold front will approach the northern Gulf on Thu night with strong to near gale force gap winds expected ahead of the front north of 29.5N. 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. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Agricultural burning over Central America continues to produce smoke across the region and may occasionally reduce visibilities off the coast of Guatemala and El Salvador. Gulf of Papagayo: Fresh to locally strong NE to E winds will pulse over the Gulf of Papagayo during the overnight and early morning hours through Wed. Winds will diminish to gentle speeds by late week as the local pressure gradient weakens with distant high pressure moving away from the area. Elsewhere, light to moderate winds will persist through Sat night. A significant Southern Hemisphere S to SW swell event will move into the Ecuador offshore waters on Thu and propagate northward across the region through Sat night. Seas will build to 7-10 ft near the Galapagos Islands by Thu night with a peak wave period 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. REMAINDER OF THE AREA... A building high pressure ridge extends SE across the northern waters. Moderate to occasionally fresh trades will prevail through Thu south of the ridge axis with seas generally 5-7 ft. As the ridge weakens Fri into the weekend, wind speeds will diminish slightly in response to the weakening pressure gradient. Low pressure centered NE of the Hawaiian Islands near 24N147W will slowly track NE and gradually weaken. Overnight scatterometer data showed an area of fresh to locally strong E to SE winds roughly from 20N to 24N west of 138W within the enhanced pressure gradient ahead of the associated frontal system, and has shrunken slightly in areal coverage this afternoon. Fresh to strong SE winds with seas to 8 ft will continue over the far western portion of high seas domain this evening before conditions subside tonight. Looking ahead, a significant S to SW swell event will move into the southern waters on Wed and propagate northward through the end of the week and into the weekend. Seas will build to 12 ft south of the Equator near 105W on Thu with 8 ft seas spreading as far north as 07N by Fri night. $$ Stripling