476 AXPZ20 KNHC 091553 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Apr 9 2024 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... ...GULF OF Tehuantepec GALE WARNING... The next gap wind event across the Tehunatepec region is expected by Thu morning as a ridge builds across the eastern slopes of the Sierra Madre Mountains in Mexico, behind a cold front moving across the Gulf of Mexico. Wind are forecast to increase to minimal gale force by Thu morning. Then, winds will further increase to 35 to 40 kt Thu night into Fri, with seas building to 14 or 16 ft. Large seas generated from this strong gap wind event will spread well away from the Tehuantepec area, with seas 8 ft or greater reaching as far west as 104W on Fri night. Marine interests transiting across or in the Gulf of Tehuantepec Fri night into Sat should be aware of this upcoming gap wind event, and take the necessary action to avoid this hazardous marine conditions over the affected waters. Winds are forecast to diminish below gale force by Sat night. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more information on this event. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from northern Colombia, westward to 08N90W to 04N110W. The ITCZ continues to 04N110W to 04N125W to beyond 03N140W. Scattered moderate to isolated strong convection can be found from 04N to 10N between 79W and 110W, and within about 150 nm N of the ITCZ between 120W and 130W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A Gale Warning has been issue for the Gulf of Tehuantepec. Please, see the Special Features section for more details. High pressure is the main feature controlling the wind regime across the offshore forecast waters of Baja California. Moderate to fresh NW to N winds are over most of the offshore waters of Baja California with fresh NW winds near Cabo San Lucas. Seas with these winds are 8 to 9 ft based on altimeter data. In the Gulf of California, gentle to moderate NW winds are S of 27N while moderate to fresh NW winds are seen N of 30N. Light to gentle winds are elsewhere. Seas are 3 to 4 ft with the strongest winds and 1 to 3 ft elsewhere. Light to gentle west to northwest winds dominate the remainder of the Mexican offshore waters with seas of 4 to 6 ft due to a mixture of long- period southwest and northwest swell. Seas are 5 to 7 ft over the waters surrounding the Revillagigedo Islands due to a prolonged long- period northwest swell moving through those waters. For the forecast, high pressure will remain in control of the weather pattern across the offshore forecast waters of Baja California for the next few days. Winds offshore Baja California will diminish to mostly moderate speeds today. The northwest swell producing seas of 8 to 9 ft north of 25N will slowly subside today into this evening. In the Gulf of California, winds will generally become light and variable on Thu throughout. On Fri, winds over the northern part of the Gulf are forecast to become fresh in speeds, south to southwest in direction, then increase to fresh to strong speeds Fri night prior to the approach of a cold front. Gentle to locally moderate winds will prevail elsewhere with slight to moderate seas. The next gale force gap wind event in the Gulf of Tehuantepec is forecast to begin Thu morning. It will likely persist through Sat. Seas are expected to peak to around 16 ft with this upcoming event. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR Fresh to strong east winds in the Gulf of Papagayo region and west from there to near 90W. Seas are 4 to 6 ft with these winds. Gentle to moderate north winds are south of the Gulf of Panama west of 79W while light variable winds are east of 79W. Generally light to gentle southwest to west winds are elsewhere. Seas are 4 to 6 ft due to a long-period south to southwest swell, except for slightly higher seas of 5 to 7 ft over the waters between the Galapagos Islands and Ecuador. Scattered showers and thunderstorms are over the offshore waters of Costa Rica, Panama and Colombia. Winds and seas may be higher in and near this activity as it is expected to stay active today through late on Wed. Hazy conditions observed along and just offshore northern Central America, northward of northern Nicaragua are due to mostly smoke produced by agricultural fires. For the forecast, the fresh to strong east winds in the Gulf of Papagayo region will diminish to moderate speeds early this afternoon and to gentle to moderate speeds through Thu. Light to gentle winds and slight to moderate seas due to a long-period south to southwest swell are expected elsewhere through Thu. Looking ahead, expect increasing winds to fresh to strong speeds, with seas building to 8 to 10 ft in the Papagayo region early on Fri. These winds may reach near gale-force late Fri night into early Sat while at the same time fresh northerly winds start in the Gulf of Panama with seas likely building up to 7 ft. Abundant moisture drawn in by a very moist and unstable southerly wind flow is expected to persist across the offshore waters of Costa Rica, Panama and Colombia supporting the development of scattered to numerous showers and thunderstorms over those waters. ...REMAINDER OF THE AREA... High pressure of 1030 mb that is analyzed well to the northeast of the Hawaiian Islands is the main feature influencing the weather pattern over the waters north of the ITCZ and west of about 110W. The pressure gradient between the high pressure and relatively lower pressure found in the vicinity of the ITCZ is sustaining a rather large area of fresh to strong trade winds mainly from about from 08N to 18N west of about 130W. Seas are 8 to 12 ft with these winds based on altimeter satellite data passes and on a couple of ship observations. Mostly fresh northeast winds along with moderate seas are present elsewhere. For the forecast, the aforementioned high pressure will shift eastward through Thu as it weakens with the approach of a cold front that is expected to push south into the far northwest part of the area. This upcoming process will mean that the area of fresh to strong trade winds confined to mainly the western waters will diminish in areal coverage. Seas produced by these winds will subside going into the end of the week. $$ GR