000 AXPZ20 KNHC 182204 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Mar 18 2024 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 2205 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Gale Warning: High pressure will build behind a cold front moving through the Gulf of Mexico early this week. This pattern, along with local drainage flow effects, will support gap winds to minimal gale force to pulse across the Gulf of Tehuantepec late Mon evening into early Tue morning. And pulse to minimal gale-force winds again late Tue evening into Wed morning. Expect sustained winds to briefly reach 35 kt during this times, with seas building as high as 10 ft downstream across the Gulf of Tehuantepec early Tue through Wed. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N78W to 04N90W to 03N107W. The ITCZ continues from 03N107W to 04N128W to 03N140W. Scattered moderate convection is noted along the trough from 04N to 06N between 83W and 86W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about a gale warning for the Gulf of Tehuantepec. A surface ridge extends from north of the area off the U.S. west coast, to off Baja California to off Cabo Corrientes. Recent ASCAT pass depicted moderate to fresh NW winds across the central and southern Gulf of California, funneling between this ridge and lower pressure over central Mexico. Elsewhere, this pattern is maintaining gentle to moderate breezes across the offshore waters of Mexico. Moderate combined seas prevail everywhere, including most of the Gulf of California. For the forecast, as described in the Special Features section, near-gale to gale force gap will start tonight over the Gulf of Tehuantepec, associated with a cold front moving into southern Mexico. Winds will pulse to gale force again on Tue night. These gap winds and associated rough seas will diminish across the Gulf of Tehuantepec by late Wed. Farther north, expect moderate to fresh NW winds from the central Gulf of California to Cabo Corrientes to persist through Tue as the high pressure builds west of the region and low pressure deepens over central Mexico. These winds will diminish through late Tue. Beyond Tue, gentle to moderate winds and seas 4 to 6 ft will prevail. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR Latest scatterometer data confirmed the presence moderate to fresh NE gap winds across the Gulf of Papagayo. This gap wind event is due to a combination of local drainage effects and a relatively tight gradient related to high pressure north of the area. Seas within this winds are 3 to 6 ft. Elsewhere seas 3 to 5 ft seas prevail except, seas to 8 ft persist close to the south of the offshore waters around the Galapagos in the southern swell. For the forecast, high pressure north of the area will continue to support pulses of fresh northeast to east winds in the Papagayo region into Tue morning, then possibly pulsing each night until Thu night. Light to gentle winds and moderate seas will continue elsewhere through the forecast period. Farther south, southerly swell reaching 8 ft will persist through Tue evening from offshore Ecuador to the Galapagos Islands. ...REMAINDER OF THE AREA... A 1012 mb broad area of low pressure is located near 23N134W. This low is associated with a broad, negatively tilted mid to upper level trough reaching from northwest of the region, where related divergent flow aloft continue to support clusters of showers and thunderstorms. Scattered moderate to isolated strong convection is evident to the southeast of the low center near 19N132W in where recent scatterometer data depicted localized near- gale force to gale winds out of the south. Broad surface ridging is in place north of 20N, supporting mostly gentle breezes across the region, except for moderate trade wind flow over tropical waters from 08N to 16N. NW swell of 6 to 7 ft covers most of the region west of 105W, with seas to 9 ft in the area of moderate trade winds, and farther south of the equator where a component of SE swell is adding to the mix. Combined seas of 5 to 7 ft in mixed NW and S swell are evident east of 105W. For the forecast, low pressure west of the area along the surface trough will move eastward tonight, with winds increasing to moderate to fresh along 140W and north of 21N. The low may linger through the early part of the week before weakening and opening to a trough. Shorter period wind waves created by moderate to fresh swell from 05N to 15N west of 110W will mix with the longer period NW swell propagating across the region to maintain 8 to 9 ft combined seas in the area of moderate to fresh trade winds through mid week. Farther south, the southerly swell will subside Tue night. $$ KRV