000 AXPZ20 KNHC 011602 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Sep 1 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 1200 UTC surface analysis and satellite imagery through 1540 UTC. ...TROPICAL WAVES... A tropical wave is along 85W, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 03N-10N between 83W-91W. This area of disturbed weather could become a tropical depression by the middle to latter part of next week as it moves west-northwestward, and it has a medium chance of tropical cyclone formation within the next 7 days as it moves WNW at about 10 kt. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from Costa Rica near 10N86W to 14N109W to 06N131W. The ITCZ continues from 06N131W to 07N140W. Scattered moderate to isolated strong convection is noted from 02N to 09N between 77W and 98W and from 05N to 12N between 106W and 118W. Scattered moderate convection is noted from 04N to 22N between 98W and 115W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface trough extends from 16N118W to 24N114W. East of this trough and in a zone of upper-level diffluence, scattered moderate convection is noted across portions of the Gulf of California and offshore Jalisco. Moderate N winds and 7 ft seas in long-period S swell are in the Gulf of Tehuantepec. Light to gentle winds dominate the waters, except in the northern Gulf of California where fresh to locally strong S winds prevail. Seas are generally 5 to 7 ft, except 2 to 5 ft in the Gulf of California. Long period S to SW swell dominates, except north of Cabo San Lazaro offshore Baja California, where NW swell is the dominant swell. For the forecast, pulsing fresh to locally strong S winds will continue in the northern Gulf of California through tonight. Fresh to strong northerly winds will pulse in the Gulf of Tehuantepec tonight through Sat night. Winds will be moderate or weaker elsewhere through Sat night. Winds will increase to fresh nearshore Baja California Sun evening through Mon night as the pressure gradient tightens along the peninsula. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds prevail across the offshore waters N of 04N, except for moderate NE to E winds in the Papagayo region. Seas north of 04N are 5 to 8 ft in long-period south to southwest swell. To the south of 04N, including the waters offshore Colombia and in between Ecuador and the Galapagos Islands, moderate S winds with seas of 6 to 9 ft are present due to long-period S to SW swell. Scattered moderate isolated strong convection is noted offshore Costa Rica in association with the tropical wave mentioned in the tropical waves section above. For the forecast, moderate to locally fresh south to southwest winds will continue between the coast of Ecuador and the Galapagos Islands through the weekend. Long period S to SW swell will move through these waters today into Sat, increasing seas to 8-9 ft through early Sun. Swell of 6-8 ft will reach the waters offshore Panama and Costa Rica this weekend. Elsewhere, light to gentle variable winds will prevail, except locally moderate to fresh near the Gulfs of Papagayo and Fonseca. ...REMAINDER OF THE AREA... The post-tropical remnant low of former Tropical Cyclone Irwin is centered near 18.5N139.5W with an estimated central pressure of 1010 mb. It is moving westward at 5 kt. A tight pressure gradient between the low and strong high pressure to its north is keeping fresh to strong winds in the northwest semicircle from the low to 23N and W of 137W. Seas are 10-12 ft in this area. Elsewhere north of 18N and west of 135W, moderate to fresh NE winds and 7 to 10 ft seas prevail. Winds are mainly moderate or weaker across the remainder of the open waters north of 05N, with seas of 6 to 8 ft. South of 05N and east of 120W, moderate S winds and seas of 7-10 ft in long period S swell prevail. For the forecast, the post-tropical remnant low of Irwin will move west of 140W later today. Fresh to strong winds and elevated seas will continue to accompany the low. Elsewhere, northerly swell well W of Baja California will subside this afternoon. Long period S swell will push northward across the Equator today with seas of 8-10 ft south of 06N and east of 120W into Sat before subsiding late in the weekend. The broad north- south oriented surface trough near 20N is expected to move from along 117W to 120W by the weekend, resulting in shifting winds. $$ Hagen