000 AXPZ20 KNHC 132118 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat May 13 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 2010 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75.5W to 05.5N80W to 09N87W to 05N118W. The ITCZ extends from 05N120W to 04N136W to beyond 02N140W. Scattered moderate to strong convection is noted from 01.5N to 06.5N east of 96W and from 01.5N to 07N west of 105W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The gradient between high pressure NW of the area and surface troughing over NW Mexico is gradually weakening today, and is supporting moderate to locally fresh NW to N winds across the offshore waters of the Baja California Peninsula that extend southward to the Revillagigedo Islands. Midday scatterometer data showed fresh NW winds within 45 nm of the coast of Cabo San Lucas. Seas across this area are 5-7 ft. Light to gentle NW to W winds generally prevail across the remaining Mexican offshore waters from Cabo Corrientes to Tehuantepec. Seas there are 5-7 ft in mixed NW and SW swell. In the Gulf of California, mainly light and variable winds prevail, with seas of 3 ft or less, except 4-5 ft near the entrance in S-SW swell. Hazy skies persist across the near and offshore waters from Las Tres Marias to Tehuantepec due to lingering smoke from agricultural fires. For the forecast, high pressure NW of the area will shift northward and weaken through the weekend, leading to a weak pressure gradient across the region, and gentle to moderate winds area-wide Sat through Thu. A surge of fresh to strong gap winds is possible in the Gulf of Tehuantepec beginning early Mon morning then diminishing Tue afternoon, building seas to 6-8 ft. Reduced visibilities in haze are possible in the S and SW Mexico offshore waters due to smoke produced by agricultural fires. Moderate S swell will dominate seas offshore S and SW Mexico Tue and Wed. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure gradient across the region continues to support winds of only light to gentle speeds across the majority of the Central America and northern South America offshore waters, with localized gap winds of 15-18 kt downwind of the Gulf of Papagayo. Seas are 5-7 ft in S-SW swell offshore Ecuador to the Galapagos Islands, and 3-6 ft elsewhere. Scattered showers and thunderstorms continue offshore of Colombia. Hazy skies persist from the Papagayo region to Tehuantepec due to lingering smoke from ongoing agricultural fires, with visibilities likely near 5 nm offshore from the Gulf of Fonseca to Tehuantepec. For the forecast, seasonally tranquil conditions will persist across the offshore waters through the middle of next week. Moderate gap winds across the Papagayo region will pulse to fresh to strong each night before diminishing Mon morning. Building SW swell will reach the Galapagos Islands early Mon, then reach the nearshore waters of Central America early on Tue, resulting in peak seas of 7-9 ft on Tue. Reduced visibilities in haze are expected from the Guatemala to the Costa Rica offshore waters due to smoke produced by ongoing agricultural fires. New SW swell should reach the Galapagos waters early Thu. ...REMAINDER OF THE AREA... The pressure gradient between subtropical 1023 mb high pressure near 30N132W and lower pressure along of the ITCZ is supporting moderate to locally fresh NE to E tradewinds from 05N to 15N and west of around 120W per afternoon scatterometer data. Seas are 6-9 ft across this area per recent altimeter data. Light to gentle variable winds and 6-8 ft seas in mixed swell are north of 15N and west of 120W, south of the high. However, building NW swell has entered NW portions of the area, where seas have built to 7-9 ft. Just NW of the area increasing S winds of 15-20 kt are occurring just ahead of an approaching cold front. Elsewhere, winds are gentle to moderate, with 5-8 ft seas in mixed swell, highest S of the Equator and west of 102W. For the forecast, little change is expected in the tradewinds through today, with seas generally 6-9 ft in merging NW and S swell, and NE wind waves. Tonight through Mon, the trades are anticipated to begin a weakening trend as the high pressure weakens and shifts farther northward. Fresh to locally strong winds north of the area offshore Point Conception, California will send fresh N seas of 6-8 ft southward to 27N between 120W and 133W this afternoon through the remainder of the weekend. A cold front will move slowly into the far NW waters Sun afternoon, with a brief period of fresh to strong southerly winds ahead of it. The front will weaken and gradually dissipate through Wed. NW swell generated well NW of the area will move across the NW and W waters through Mon night to produce seas of 8-11 ft north of 20N and west of 135W. Meanwhile, cross equatorial S to SW swell will maintain seas around 8 ft along and south of the Equator. New cross-equatorial S-SW swell should reach the Equator late Sun and build seas 8-10 ft south of the ITCZ early Mon through Tue night before subsiding. Tranquil conditions will dominate across the open waters by the middle of next week. $$ Stripling