000 AXPZ20 KNHC 261606 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Sep 26 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 1510 UTC. ...TROPICAL WAVES... A tropical wave is entering the eastern Pacific, passing through western Panama north of 05N, along 82W. Scattered moderate to strong convection is evident N of 02N and E of 85W. A tropical wave is analyzed along 122W from 04N to 17N, moving W at 10 to 15 kt. Scattered moderate to strong convection is active from 10.5N to 14N between 118W and 126.5W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N74.5W to 12N91W to 09N108W to 08N121W. The ITCZ extends from 12N136W to beyond 10N140W. Scattered moderate isolated strong convection is noted from 05.5N to 10N between 86W and 113W. Scattered moderate convection dots the waters from 07N to 09N between 130W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends from 1021 mb high pressure centered near 29N126W to the Revillagigedo Islands. Overnight ship observations showed fresh NW winds off Baja California, and are assumed to have increased slightly this morning to the north of Punta Eugenia. Seas there are likely 6 to 8 ft. The pattern is also supporting moderate NW winds over the central Gulf of California, with lighter winds elsewhere inside the Gulf. Gentle breezes are noted farther south to Puerto Angel, where seas are 4 to 6 ft seas. Fresh northerly gap winds developed overnight across the Gulf of Tehuantepec and have increased to strong in a narrow plume to the N of 14N. Seas there are 6 ft. Scattered moderate to strong thunderstorms are lingering within 120 nm of the coast of Mexico between Acapulco and Punta San Telmo. For the forecast, fresh to locally strong NW winds will persist off Baja California north of Cabo San Lazaro into mid week between high pressure north of the area and a trough over the Gulf of California. Winds will then gradually diminish Wed through Fri as the ridge shifts NW. Seas will build 8 to 12 ft in new NW swell offshore Baja California today through Thu before slowly subsiding Fri through Sat. Farther south, moderate to fresh N gap winds will pulse to strong across the Gulf of Tehuantepec tonight. Looking ahead, expect fresh westerly gap winds over the northern Gulf of California starting late Fri ahead of an approaching cold front, possibly reaching near-gale force by Sat night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable breezes are evident off northern Central America, north of the monsoon trough, with gentle SW breezes noted farther south. Combined seas are 4 to 5 ft across the region with southerly swell. Scattered moderate to strong thunderstorms associated with a tropical wave prevail N of 02N and E of 85W, and are impacting the near shore waters of Costa Rica and Panama. For the forecast, gentle to moderate winds will prevail to the north of 07N with seas 5 ft or less through Sat night. Gentle SW winds farther south will increase to moderate mainly south of 05N starting late Tue, with seas building to 6 to 8 ft in southerly swell off Ecuador. ...REMAINDER OF THE AREA... The remnant low of T.C. Fourteen-E is fully exposed near 14.5N134W with a pressure estimated to be 1010 mb. Overnight scatterometer satellite data indicated mostly fresh winds are still accompanying the low within 90 nm in the northern semicircle, implying rough seas near the low pressure as well, and are assumed to still be 8-9 ft there. Farther north, several recent altimeter satellites have indicative of long-period NW swell crossing 30N and moving into the discussion waters, and accompanying a cold front moving through the north-central Pacific. This satellite altimeter data showed that seas were 1 to 2 ft higher than the global wave models, and that this swell is arriving about 6 hours faster than previously forecast. To the south, satellite altimeter data also showed seas to 8 ft crossing the equator between 100W and 120W. This is part of a large area of southwest cross-equatorial southerly swell moving into the waters south of 03N and west of 100W. For the forecast, the remnants of T.C. Fourteen-E will weaken to a trough during the next 48 hours while moving west-southwestward. The cold front crossing 30N140W will stall and dissipate north of 28N and west of 135W into mid week. High pressure north of the front will increase the pressure gradient to the west of 125W, and freshen the winds Tue through Thu. Large, long-period NW to N swell will propagate into the waters north of 22N by this evening, then cover the area north of a line from Baja California Sur to 10N120W to 10N130N by late Wed. Meanwhile high pressure will build north of the area in the wake of the front, supporting fresh to strong trade winds by Thu from 10N to 20N west of 120W, with combined seas building to 13 ft in a mix of NW swell and shorter period NE to E wind waves. Farther south, southerly swell will continue to move across the equator, supporting combined seas of 8 to 9 ft south of 03N and west of 115W by late Thu. $$ Stripling