000 AXPZ20 KNHC 190939 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Apr 19 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 0820 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N74W to 07N84W to 03N100W. The ITCZ extends from 03N103W to 05N123W, and then again from 04N127W to beyond 02N140W. Another ITCZ segment is farther south, extending from 00.5S102W to beyond 03.4S116W. Scattered moderate isolated strong convection is noted from 05N to 07.5N between 82W and 91W. Scattered moderate convection is noted from 01.5N to 06N between 94W and 110W. Scattered moderate to strong convection is seen S of 01S between 87W and 116W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... NW winds off the coast of Baja California Norte have increased tonight, as high pressure has built southeastward into the region behind a dissipating cold front. Recent satellite wind data showed strong NW winds offshore of southern California, and fresh to strong winds from Punta Eugenia northward. Moderate to fresh NW winds prevail elsewhere offshore of Baja Sur tonight. Recent buoy reports and altimeter data show seas offshore Baja Norte and along 30N have recently built to 9 ft, and are expected to build to 11-12 ft by morning. Seas are 5 to 8 ft elsewhere off Baja California south of 28N. Gentle to moderate breezes persist elsewhere over the Mexican offshore waters further southeast, with 4 to 6 ft combined seas in open waters with a mix of NW and SW swell. For the forecast, 1026 mb high pressure extends from 37N141W to near the Revillagigedo Islands, and will support fresh to occasionally strong NW winds off Baja California north of Cabo San Lazaro through early Thu. The high pressure will drift westward and slowly weaken late Thu through Sun leading to a dimishing trend in winds and seas across the regional waters. Looking ahead, a new round of large NW swell is expected to move into the waters off Baja California north of Punta Eugenia late Sat through Sun. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The base of an upper level trough across central America is supporting small clusters of showers and thunderstorms from just offshore of NW Panama to about 90 nm southwest of southeastern Costa Rica, extending well offshore to 90W. High pressure north of the area is supporting moderate to fresh gap winds across the Gulf of Papagayo, and moderate to locally fresh northerly winds over the Gulf of Panama just southeast of the Azuero Peninsula. Light to gentle breezes are noted elsewhere. Combined seas are 4 to 6 ft downstream of the Gulf of Papagayo, and mostly 3 to 4 ft elsewhere. For the forecast, the high pressure north of the area will support fresh to occasionally strong gap winds pulses through Thu across the Gulf of Papagayo and the coast of Nicaragua. Moderate winds in the Gulf of Panama will briefly pulse to fresh tonight and Wed night. Elsewhere, light to gentle variable winds and moderate seas in SW swell will prevail. A weak pressure pattern will develop across the western Caribbean Fri night through the weekend and lead to gentle winds across most of the local area. ...REMAINDER OF THE AREA... High pressure of 1026 mb is centered N of the area near 37N141W and extends a ridge southeastward to near the Revillagigedo Islands. A front sinking towards 30N earlier has dissipated. Recent scatterometer satellite data showed moderate to fresh NE trade winds from 06N to 24N west of 120W, between a trough in the deep tropics along 124W-125W and the subtropical ridge north of 20N. Recent altimeter satellite data showed seas in this area are 7 to 8 ft mixed NE and NNW swell. Thunderstorms near the surface trough are isolated between 06.5N and 09N. Gentle to moderate winds are noted elsewhere to the north, where seas are 7 to 10 ft in building NNW swell. For the forecast, winds and seas over the tropical Pacific west of 125W will gradually diminish through early Sat as high pressure weakens north of the area, and the surface trough weakens and shifts W of 140W. New NNW swell in excess of 8 ft moving into the waters north of 25N tonight will spread southward through Thu, with highest seas occurring this morning E of 130W. For late Fri through Sun, high pressure will shift westward and lead to a modest decrease in trade winds W of 125W, with seas gradually subsiding to 7-8 ft by late Sun. $$ Stripling