000 AXPZ20 KNHC 071521 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1521 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from 09N83W to 09N90W to 08N92W to 07N102W. The ITCZ axis continues from 07N102W to 09N108W to 06N131W, then resumes from 06N134W to beyond 06N140W. Numerous moderate and scattered strong convection is observed from 03N to 07N east of 80W and within 120 nm of the trough between 83W and 91W. Scattered moderate and isolated strong convection is present within 240 nm south of the trough between 91W and 97W and within 180 nm of the ITCZ between 112W and 123W and between 126W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A building high pressure ridge extends SE from near 32N130W across the Baja California offshore waters to near Cabo Corrientes. 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 tonight into early Wed 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 speeds with gradually subsiding seas into the weekend. Seas in the southern Mexico offshore waters will build to 5-7 ft Fri through Sat as long period S to SW swell moves into the region. Ongoing agricultural burning in southeast Mexico may occasionally reduce visibilities in haze and smoke over the adjacent offshore waters. Gulf of California: SW to W gap winds over the northern Gulf have likely diminished below fresh speeds this morning. 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 winds will prevail over the central and southern Gulf during the next several days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Agricultural burning over Central America may occasionally reduce visibilities in haze and smoke 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 north 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 24N149W 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. Fresh to strong SE winds with seas to 8 ft will continue over the far western portion of high seas domain today 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. $$ Reinhart