000 AXPZ20 KNHC 180928 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Apr 18 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 0600 UTC surface analysis and satellite imagery through 0800 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N75W to 05N84W to 06N89W to 03.5N104W. ITCZ continues from 03.5N105W to 05N119W. A second ITCZ is located S of the equator from 00.5S100W to 01.5S110W to beyond 02S120W. Scattered moderate to strong convection is noted from 02.5N to 08N between 83W and 96W. Scattered moderate isolated strong convection is noted S of 00N between 88W and 98W and from 02.5N to 09.5N between 101W and 121W. Scattered strong convection is noted S of 01S W of 116W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Winds continue to diminish in strength and areal coverage across the Tehuantepec tonight, as high pressure north of the area weakens and shifts eastward. Northerly winds are assumed to have diminished to 20-25 kt in recent hours, with seas still 7-8 ft and extending downstream to near 14.5N95W. Winds and seas will gradually diminish further overnight, and fall below 20 kt around sunrise Tue. Farther north, a broad surface ridge extends from 1028 mb high pressure centered near 40N150W southeastward to near the Revillagigedo Islands. Recent scatterometer satellite data and ship observations indicate moderate to locally fresh NW winds winds off Baja California, between the ridge and lower pressure over north-central Mexico. Seas have built to 5 to 8 ft in fresh NW swell across this area, except 8 to 9 ft across the NW waters well offshore of Baja Norte. Gentle to moderate winds persist elsewhere off Mexico to Puerto Angel. Combined seas are 4 to 6 ft elsewhere in open waters. Inside the Gulf of California, winds have shifted to SW to W and are producing areas of fresh gap winds across several sections of the Gulf. Seas are 2 to 3 ft except to 4 ft downstream of the gap winds. For the forecast, the high pressure over the eastern Pacific will support fresh to occasionally strong NW winds off Baja California north of Cabo San Lazaro through late Thu, with combined seas reaching to 12 ft in NW swell offshore Baja Norte Wed morning. The high pressure NW of the region will weaken and drift northwestward Fri through Sat leading to a dimishing trend in winds and seas across the area waters. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Recent scatterometer wind data showed moderate to fresh gap winds across the Papagayo region extending offshore to 87W. Seas are 4 to5 ft there. Moderate to locally fresh N winds are across the Gulf of Panama, and extend southward to 06.5N, where seas are 3 to 4 ft. Elsewhere, light to gentle variable winds and seas 4-6 ft prevail. Fuego Volcano in Guatemala has been emitting ash overnight, which has moved due southward to near the coast. This small ash plume is expected to disperse before reaching to the local coastal waters, but may be seen along the coast early this morning. For the forecast, high pressure north of the area will support fresh to occasionally strong gap winds pulses through mid week across the Gulf of Papagayo and waters of southern Nicaragua. Moderate northerly winds in the Gulf of Panama will briefly pulse to fresh Tue and Wed nights. Elsewhere, light to gentle variable winds and moderate seas in SW swell will prevail. ...REMAINDER OF THE AREA... Recent scatterometer satellite data showed fresh to strong NE trade winds from 05N to 16N west of 120W, between a trough in the deep tropics along 122W and the subtropical ridge north of 20N. Recent altimeter satellite data confirmed combined seas in this area are 7 to 9 ft mixed NE and NW swell. Scattered thunderstorms near the surface trough have diminished significantly in recent hours. Gentle to moderate winds are noted elsewhere to the N, where seas of 5-7 ft prevail. For the forecast, winds and seas over the tropical Pacific west of 125W will gradually diminish through mid week as high pressure weakens north of the area. New longer period NW swell in excess of 8 ft will move into the waters north of 20N through Wed, with highest seas reaching 12 ft along 30N120W. For Thu through Sat, combined seas of 8 to 9 ft will persist north of 25N and east of 125W to near the Baja California coast. Seas associated with fresh trade winds in NW swell will persist from 05N to 20N west of 125W. $$ Stripling