000 AXPZ20 KNHC 262215 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2110 UTC. ...TROPICAL WAVES... A tropical wave is entering the eastern Pacific, passing through Panama and Costa Rica north of 05N, along 83W, moving .w at 5 to 10 kt. Scattered moderate to strong convection is evident from 02.5N to 11N and E of 87W. A tropical wave is analyzed along 124W from 04N to 17N, moving W at 10 to 15 kt. Scattered moderate to strong convection is active from 10N to 14.5N between 119W and 126W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N74.5W to 09N101W to 11N112W TO 09.5N125W. The ITCZ continues from 09.5N125W to beyond 09N140W. Scattered moderate isolated strong convection is noted from 06N to 10N between 90W and 113W and from 06N to 09N between 128W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends from 1024 mb high pressure centered near 30N129W to just W of the Revillagigedo Islands. Afternoon satellite scatterometer data showed fresh NW winds offshore Baja California. Seas there have increased slightly to 7-8 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 continue across the Gulf of Tehuantepec in a narrow plume to the N of 14N. Seas there are 6-7 ft. Scattered moderate thunderstorms are lingering offshore of southwestern Mexico, from 16N to 18N within 120 nm of the coast of Mexico between 103W and 105W. This convection has weakened considerably in the past several hours and has shifted W-NW and away from shore. For the forecast, fresh to locally strong NW winds will persist off Baja California north of Cabo San Lazaro through Wed morning 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 13 ft in new NW swell offshore Baja California this afternoon through Thu before slowly subsiding Thu night 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 to start Fri afternoon ahead of an approaching cold front, possibly reaching near-gale force by Sat evening. ...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. Gentle S to SW breezes are noted farther south, except moderate winds S of 04N. 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 02.5N and E of 87W, and are impacting the offshore waters of Costa Rica and Panama. For the forecast, gentle to moderate winds will prevail to the north of 06N with seas 5 ft or less through Sat night. Gentle to moderate SW winds farther south will increase to moderate mainly south of 05N starting early Thu, before diminishing Fri night. Seas south of 05N will build to 6 to 8 ft in southerly swell beginning Wed and persist through Fri evening. Highest seas to near 9 ft will occur to the SW of the Galapagos. ...REMAINDER OF THE AREA... The remnant low of T.C. Fourteen-E is fully exposed near 14N136W with a pressure estimated to be 1011 mb. Afternoon scatterometer satellite data indicated mostly fresh winds are still accompanying the low within 300 nm in the northern semicircle, implying a large area of rough seas of 8-9 ft there. Widely scattered small clusters of moderate convection have again developing across the eastern semicircle of this low, seen from 60 to 200 nm E of the center. Farther north, several recent altimeter satellites passes have indicated of long-period NW swell crossing 30N and moving into the discussion waters, accompanying a frontal trough approaching 30N. This satellite altimeter data showed that seas were 1 to 3 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 110W 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 24 hours while moving west- southwestward. The frontal trough approaching 30N140W will stall and dissipate north of 28N and west of 135W on Wed. High pressure north of the front will increase the pressure gradient to the west of 125W, and freshen the winds tonight 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. This swell will raise seas to around 14 ft along 29-30N tonight. Meanwhile high pressure will build north of the area in the wake of the frontal trough, supporting fresh to strong trade winds by Wed from 11N to 22N west of 122W, 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 Thu. $$ Stripling