000 AXPZ20 KNHC 100939 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0800 UTC. ...SPECIAL FEATURES... Gulf of California Gale Warning: Strong high pressure building into the region from the NW, behind a dry cold front entering the far northern Gulf tonight is producing strong to gale force winds surging over the extreme northern Gulf waters north of about 31N. These northwesterly winds will spread southward across the Gulf this morning and gradually diminish below gale force by mid morning. Seas will quickly build to 6-9 ft during this period. As the strong high pressure continues to build southeastward across the region today, and a large low pressure systems deepens across the Southern Plains states of the U.S., the strong NW winds will spread the full length of the Gulf through this evening. Winds and seas will begin to diminish north of the Tiburon Basin this afternoon, while seas build to 5- 8 ft across the remainder of the Gulf. Wind and seas will then gradually diminish across the basin Wed night through Thu. 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 08N74W TO 11N86W TO 06N100W. The ITCZ extends from 05N103W TO 06N122W to beyond 04N140W. Scattered moderate isolated strong convection is noted from 03N to 09N between 80W and 95W, and within 270 nm north of the ITCZ west of 112W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong high pressure of 1042 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. Overnight 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. As this very strong ridge continues to build across the offshore waters today, expect strong NW winds top spread southward to Cabo San Lazaro by late morning, with fresh winds elsewhere N of 20N. Seas of 9-14 ft will generally prevail by this afternoon. Winds will remain fresh north 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 tonight. Gulf of Tehuantepec: A narrow plume of fresh northerly gap winds continues across the Gulf of Tehuantepec tonight, but will diminish to gentle to moderate today. Winds will then switch 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 through tonight, before shifting offshore Fri through early next week. Winds may briefly become fresh Mon night and Tue. 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 Wed night 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 39N138W. Overnight scatterometer data revealed fresh to strong winds were expanding in coverage across the high seas roughly north of 10N and west of 120W. Earlier altimeter data in this region showed seas ranging from 9- 14 ft. South 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. Near gale force N winds will develop just beyond the Baja California Norte offshore waters tonight with seas in this area building to 12-16 ft. 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 105W. This swell will gradually decay through late week. Elsewhere, cross equatorial SW swell across the far southern waters will mix with NW swell tonight through Wed night to produce 8-9 ft seas generally S of 07N between 100W and 120W. $$ Stripling