000 AXPZ20 KNHC 101543 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Apr 10 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. ...SPECIAL FEATURES... Gulf of California Gale Warning: Strong high pres building into the region from the NW behind a dry cold front across the far northern Gulf has been supporting gale force winds behind the front, which are in the process of diminishing to fresh to near gale force. The fresh to near gale force winds will spread southward to the central Gulf as the front does as well through the rest of the morning and afternoon. Seas of 7-10 ft N of 30N will subside later today as the winds diminish slightly, while seas build to 5-8 ft across the remainder of the Gulf. Wind and seas will then gradually diminish across the remainder of the basin through Thu. Looking ahead, winds may increase back to gale force from 29.5N to 30.5N on Thu night due to funneling through Baja California Norte ahead of an approaching trough or front. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N83W to 06N95W. The ITCZ extends from 06N95W to 08N110W to 05N125W to 04N140W. Scattered moderate isolated strong convection is noted from 04N to 09N between 80W and 88W, from 03N to 07N between 105W and 109W, from 08N to 12N between 111W and 117W, from 05N to 10N between 126W and 134W, and also from 04N to 07N W of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong high pressure of 1041 mb is centered NW of the region and extends a broad ridge SE across the outer Baja California offshore waters to just SE of the Revillagigedo Islands. Earlier scatterometer data showed gale force NW winds offshore of southern California extending to just N of the offshore waters of Baja California Norte, where strong northerly winds then spread southward over the offshore waters to near Punta Eugenia along 26N. Seas across this area have built to 10-16 ft per recent altimeter passes. This very strong ridge is allowing for strong NW winds to spread southward to Cabo San Lazaro, with fresh winds elsewhere N of 20N. Seas of 9-14 ft will generally prevail by this afternoon. Winds will remain fresh N of Cabo San Lazaro through Fri night before diminishing this weekend as the pressure gradient relaxes over the area. Large, long period NW swell has moved beyond the Revillagigedo Islands to as far east as 100W. Expect dangerous surf conditions to persist along the coast of Baja California through Wed night. Gulf of California: Please see the Special Features section above for information about the gale warning in effect for the northern Gulf of California. Gulf of Tehuantepec: An earlier plume of fresh northerly gap winds and attendant seas to 8 ft has diminished to gentle to moderate during the past several hours. Winds will transition to onshore tonight through Sun morning. Looking ahead, the next Gulf of Tehuantepec northerly gap wind event could begin Sun night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Light to moderate mostly onshore winds will prevail across the Gulf of Papagayo region and adjacent offshore area, before shifting offshore Fri through early next week. Seas in the 4-5 ft range will gradually subside to 3-5 ft over the weekend. Gulf of Panama: Light to gentle breezes will prevail across the Gulf of Panama region through the weekend. Seas will generally remain in the 4-6 ft range through Fri night in SW swell, then subside to 3-5 ft this weekend. Elsewhere, light to gentle winds will persist through the week. Wave heights between Ecuador and the Galapagos Islands will generally remain 5-7 ft through Fri as cross equatorial, long period SW swell moves across the region. Further offshore, seas will peak around 8 ft tonight into Thu over the waters SW of the Galapagos Islands. REMAINDER OF THE AREA... A broad and strong ridge extends across the northern waters, centered on a 1042 mb high near 38N139W. Earlier scatterometer data revealed fresh to near gale force winds were expanding in coverage across the high seas roughly N of 10N and W of 120W. Earlier altimeter data in this region showed seas ranging from 9- 15 ft. S of the ridge, fresh trade winds prevail between 15N and the ITCZ west of 120W. This strong high pressure will persist north of the region through Thu night, maintaining a tight pressure gradient across most of the waters N of 15N. A large area of fresh to strong N to NE winds will persist across the northern waters through Fri before diminishing Fri night through the weekend. Seas will remain 12 ft or greater west of 130W through Thu as S swell mixes with shorter period NE wind waves. Long period NW swell continues to propagate SE across the Pacific high seas area. This swell now covers most of the waters W of 100W with a band of 8-10 ft seas extending from 04N to 15N west of 101W. This swell will gradually decay through late week. Elsewhere, cross equatorial SW swell across the far southern waters will continue to mix with NW swell through tonight to produce 8-9 ft seas generally S of 05N between 98W and 112W. $$ Lewitsky