000 AXPZ20 KNHC 110952 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Apr 11 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 0830 UTC. ...SPECIAL FEATURES... Gulf of California Gale Warning: Fresh to strong NW winds WILL prevail over the central and southern Gulf of California this morning through evening as strong high pressure builds into the region from the NW. Winds will then briefly diminish across the Gulf this evening. SW to W gap winds are expected to strengthen to gale force tonight over the northern Gulf from 29.5N to 30.5N due to funneling through passages of the mountainous terrain of Baja California Norte. Seas will quickly build to 8 ft downstream of these westerly winds. Winds will quickly subside below gale force after sunrise Fri morning. 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 10N73W TO 06.5N85W TO 07.5N96W. The ITCZ extends from 07.5N97W TO 08N112W TO 04.5N132W to beyond 04N140W. Scattered moderate to strong convection is noted from 02.5N to 07.5N between 80W and 90W, within 150 nm N of the ITCZ between 108W and 115W, within 240 nm N of the ITCZ between 109W and 128W, and from 05N to 12.5N between 132W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong 1042 mb high pressure NW of the region maintains a broad ridge extending SE along the outer Baja California offshore waters to SE of the Revillagigedo Islands near 13N104W. Overnight scatterometer data suggested fresh to locally strong northerly winds north of Cabo San Lazaro over the offshore waters, with 9-14 ft seas per recent altimeter data. The high will remain in place today and allow another northerly surge across the offshore waters of southern California to spread across the Baja California Norte waters tonight through midday Friday. This will result in strong NW winds north of Punta Eugenia and fresh winds southward to Cabo San Lazaro through Fri night. These strong winds to around 30 kt north of Punta Eugenia will build seas to 10-17 ft. Wind will diminish this weekend as high pressure weakens and moves westward. Elsewhere, long period NW swell across much of the region west of 100W will gradually decay through late week. 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. Winds and seas will diminish of the weekend, becoming generally W to NW at 15 kt or less. Gulf of Tehuantepec: Gentle to moderate onshore winds will prevail across the Gulf of Tehuantepec region through Sun. Looking ahead, the next Gulf of Tehuantepec northerly gap wind event is expected late Sun night into Mon as strong to near gale force N winds develop over the Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Light to moderate, generally onshore winds will prevail across the Gulf of Papagayo region and adjacent offshore waters through Thu night before shifting offshore Fri through Sun night but extending only outward to 88W. Seas in the 4-6 ft range will gradually subside to 3-5 ft over the weekend. Fresh to strong NE to E winds are expected across the Gulf Mon and Mon night as high pressure builds north of the area. Gulf of Panama: Light to gentle breezes will prevail across the Gulf of Panama region through Mon. 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 in long period SW swell. Further offshore, seas will peak around 8 ft tonight through Fri night over the waters SW of the Galapagos Islands. REMAINDER OF THE AREA... A strong high pressure ridge extends across the northern waters from 1042 mb high pressure centered NW of the region near 38N138W. Overnight scatterometer data showed a broad area of strong NE winds from generally north of 16N and west of 128W. Peak winds across this area were to 30 kt, while seas of 10-16 ft prevailed in mixed NE wind waves and NW swell. Elsewhere, fresh trade winds prevail south of the ridge to near the ITCZ and to the west of 115W. This tight pressure gradient south and southeast of the ridge will persist the as strong high pressure persists, before the ridge begins to weaken slightly and drift west into the weekend. Seas will remain 12 ft or greater west of 130W today as NE wind waves mix with S and NW swell. A northerly surge Thu night into Fri will reinforce strong NW winds off Baja California Norte with seas building as high as 17 ft. Long period NW swell maintains a band of 8-10 ft seas across much of the high seas from roughly 06N to 15N west of 105W. East of 120W, wave heights will gradually subside through late week as this swell decays over the region. Elsewhere, overnight altimeter data showed a region of 8-9 ft seas south of the Equator and west of 110W in merging SW and NW swell. Seas of 8-9 ft will likely persist over the far southern waters through the weekend in mixed SW and NW swell. $$ Stripling