000 AXPZ20 KNHC 010916 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0915 UTC Mon Apr 1 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 0900 UTC. ...SPECIAL FEATURES... ...Gulf of Tehuantepec Gale Warning... Scatterometer data from 04 UTC showed near gale force winds over the Gulf of Tehuantepec with strong high pressure building southward over eastern Mexico behind a Gulf of Mexico cold front. Marginal gales are likely ongoing over the Gulf of Tehuantepec early this morning as northerly winds continue funneling through the Chivela Pass. Seas will quickly build to 8-11 ft before winds diminish to fresh to strong speeds later this morning. Please read 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 the coast of Panama near 08N78W to 06N89W. The ITCZ continues from 06N89W to 05N105W to beyond 02N140W. Scattered moderate and isolated strong convection is noted from 05N to 07N between 86W and 89W and within 60 nm of the ITCZ between 121W and 128W. Elsewhere, scattered moderate convection is occurring from 03N to 05N between 132W and 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad surface ridge extends from 30N130W to the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure over Mexico is producing moderate NW winds west of Baja California. Seas have generally subsided to less than 8 ft based on recent altimeter data. A weakening cold front will approach the waters off Baja California Norte Tue night, but light to moderate winds will prevail off Baja California through midweek. Looking ahead, fresh winds are expected Fri and Fri night as a stronger ridge builds west of the region. Gulf of California: Recent scatterometer data indicated moderate to fresh NW winds over the central Gulf of California with light to moderate winds elsewhere. Winds will diminish to 15 kt or less across the region later today as the pressure gradient weakens. Moderate to fresh S to SW gap winds are expected over the northern Gulf of California Tue and Tue night ahead of a weakening cold front that will approach Baja California Norte. Gulf of Tehuantepec: See the Special Features section above for more details on the gale warning currently in effect. Northerly gap winds will pulse to 25-30 kt through Wed morning, then diminish to gentle speeds Wed night through Fri night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong winds will pulse across the Papagayo region during the overnight and early morning hours through Thu. Then, fresh winds will prevail over the Gulf Thu night through Fri night. Gulf of Panama: Generally light to moderate winds will prevail over and downstream of the Gulf of Panama through Tue. High pressure will build north of the area beginning Tue night with moderate to fresh NE winds persisting over the Gulf through Thu. Elsewhere, light to gentle winds will prevail through the week with seas gradually subsiding as SW swell decays over the region. REMAINDER OF THE AREA... A cold front over the far NW portion will cross the northern waters through tonight, then weaken Tue and Tue night as it approaches the offshore waters off Baja California Norte. Expect 8-9 ft seas in NW swell over the far NW waters today as shown by recent altimeter data west of 138W. Elsewhere, moderate to fresh trade winds prevail south of 20N and west of 125W based on recent scatterometer data. Peak seas are likely still 10-11 ft in this region given that earlier altimeter retrievals were higher than available wave guidance. High pressure will weaken over the northern waters during the next couple days, resulting in weakening trades and subsiding seas over the high seas domain. Looking ahead, low pressure will develop just north of the area Wed and pull another cold front across the northern waters Wed night into Thu. A significant NW swell event will impact the northern waters by late week as stronger low pressure tracks well north of the region. Seas will build to 12-18 ft across the NW portion by Fri night. $$ Reinhart