000 AXPZ20 KNHC 130810 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0730 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Costa Rica near 09N83W to 07N100W. The ITCZ extends from 07N100W to 04N113W to 06N132W to 03N140W. Isolated to scattered moderate to strong convection is noted from 02N to 07N between 79W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The gradient between high pressure NW of the area and surface troughing over Mexico is supporting moderate to fresh NW to N winds across the offshore waters of the Baja California Peninsula that extends southward to the Revillagigedo Islands, locally strong near Cabo San Lucas per a recent ASCAT scatterometer pass. Associated seas are 5-7 ft. Gentle to moderate 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 3-4 ft near the entrance in S-SW swell. Hazy skies persist across the near and offshore waters from Manzanillo to Tehuantepec due to lingering smoke from agricultural fires. For the forecast, fresh to locally strong NW to N winds near Cabo San Lucas will diminish over the next few hours. Seas will gradually diminish area-wide through Mon. A surge of fresh to strong gap winds is possible in the Gulf of Tehuantepec Mon morning through Tue afternoon, building seas to 6-8 ft. Otherwise, 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 Wed. Reduced visibilities in haze are possible in the S and SW Mexico offshore waters due to smoke produced by agricultural fires. ...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 very localized gap winds of 15-25 kt in the Gulf of Papagayo. Seas are 5-8 ft in S-SW swell offshore Ecuador to the Galapagos Islands, and 3-5 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 3-5 nm downwind of Papagayo and Nicaragua. For the forecast, seasonally tranquil conditions will persist across the offshore waters through early next week. Moderate gap winds across the Papagayo region will pulse to fresh to locally strong each night through Mon morning. Building SW swell to around 8 ft should begin reaching the Galapagos Islands Sun night, then reach the nearshore waters of Central America on Tue, resulting in seas of 6-7 ft. Reduced visibilities in haze are expected from the Guatemala to the Costa Rica offshore waters due to smoke produced by ongoing agricultural fires. ...REMAINDER OF THE AREA... The gradient between subtropical 1024 mb high pressure just N of the area near 31N132W and lower pressure along of the ITCZ is supporting moderate to locally fresh NE to E tradewinds from 06N to 21N and west of around 117W per recent ASCAT scatterometer data. Seas are 6-8 ft across this area per recent altimeter passes. Light to gentle variable winds and 4-6 ft seas in mixed swell are north of 21N and west of 125W near the high, except just SE of 30N140W where arriving NW swell is building seas to 7-9 ft with increasing S winds of 15-20 kt 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 104W. 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 into the NW waters through Mon 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. $$ Lewitsky