000 AXPZ20 KNHC 152205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Apr 15 2023 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure north of the area building in behind a cold front that will move across the Gulf of Mexico starting tonight and through late Mon night will create a tight enough gradient that is expected to support northerly gale-force winds through the Gulf of Tehuantepec Mon morning. This will be a short-lived event as the high pressure will weaken as it shifts eastward allowing for the winds to diminish to strong speeds on Mon afternoon. Seas are expected to peak to about 11 ft with this event before subsiding to 8 ft during Mon afternoon and to below 8 ft Mon night. Please refer to latest High Seas Forecast issued by National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from low pressure of 1008 mb over NW Colombia near 09N75W southwestward to 07N90W to 07N103W and to 08N115W, where it transitions to the ITCZ and continues to 06N127W and to beyond 05N140W. Scattered moderate to strong convection is noted from 01N to 06N between 84W-90W. Scattered moderate convection is from 02N to 05N between 79W-84W, also from 01N to 04N between 92W-95W and within 60 nm north of the ITCZ between 127W-135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on an upcoming Gulf of Tehuantepec gap wind gale-force event. A broad surface ridge extends from high pressure NW of the area to SW of Cabo Corrientes along 108W. The associated pressure gradient is producing moderate to locally fresh northerly winds across the full length of Baja California waters extending southward to offshore Cabo Corrientes and adjacent area. Localized areas of strong NW winds are near and along the coast from Cabo Corrientes to Lazaro Cardenas. Seas offshore Baja California have subsided to 4-6 ft in NW swell north of Punta Eugenia and to 5-7 ft south of Punta Eugenia. Elsewhere from the Tehuantepec region to near Acapulco, gentle to moderate west to northwest winds prevail along with seas of 3-5 ft. For the forecast, the NW swell across the Baja offshore waters will continue to subside through tonight. Gentle S to SW winds over the northern Gulf of California will briefly become fresh S to SW winds Mon night. NW to N winds are expected to increase to fresh to strong N of Punta Eugenia starting Mon night, becoming fresh to strong Wed and Wed night as the high pressure shifts eastward. These winds will be at mostly fresh speeds Thu and Thu night, with localized strong winds near Punta Eugenia. The next gap wind event in the Tehuantepec region is expected to begin Sun night, with brief gale-force winds expected Mon morning. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR The earlier fresh to locally strong winds northeast to east winds that were over the Gulf of Papagayo region have diminished to moderate to fresh as was suggested by a recent partial ASCAT data pass. Seas with these winds are 4-6 ft. Gentle to moderate N to NE winds are over the Gulf of Panama. Fresh NE winds are downstream of the Gulf from 04N to 06N between 79W-81W. Seas with both of these areas of winds are 4-5 ft. Elsewhere, light to gentle variable winds and slight seas prevail. For the forecast, weak high pressure is expected to persist across the region to the N through Sun night. This pattern will produce fresh easterly winds in the Gulf of Papagayo pulsing to strong at night and into the early morning hours through Wed night. However, seas are expected to remain below 8 ft. The gentle to moderate winds in the Gulf of Panama will briefly pulse to fresh late tonight and again at night Tue, Wed and on Thu. Elsewhere, light to gentle variable winds and moderate seas in SW swell will prevail. ...REMAINDER OF THE AREA... A 1025 mb high pressure well N of the area near 33N129W extends a ridge southeastward to offshore of Cabo Corrientes, Mexico. The ridge dominates most of the forecast waters north of 10N and west of about 110W. Recent ASCAT data passes over this area showed gentle to moderate NE to E winds. Seas with these winds are in the 5-7 ft range. The earlier noted seas of 7-9 ft due to NW swell that were over the NE part of the area have subsided considerably to 5-7 ft as indicated by an altimeter data pass that sampled a swath of this area. Light to gentle winds are present south of the ITCZ. For the forecast, high pressure will dominate the northern forecast waters over the next several days. The associated pressure gradient will support moderate to fresh trade winds over the west-central waters. An elongated zone of seas 8 to 9 ft in mixed N and E swell is expected to develop W of 114W from 08N to 16N starting late tonight through Sun night, where trade winds will freshen, then increasing to 8-10 ft Mon and subsiding on Tue. A weakening cold front will push southward across the far northern waters Tue and Tue night. A set of NW swell will follow the front reaching south of 30N and to near 26N by late Tue night. Seas of 8-9 ft are expected with this NW swell. $$ Aguirre