Tropical Weather Discussion
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Issued by NWS
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517 AXPZ20 KNHC 211551 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue May 21 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends off the coast of Costa Rica near 10N86W to a 1006 mb low pressure near 11N107W to 08N120W. The ITCZ extends from 08N120W to beyond 06N140W. Scattered moderate to isolated strong convection is noted from 04N to 13N between 78W and 110W. Scattered moderate convection is noted from 07N to 14N between 111W and 116W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong high pressure continues to stretch across the NE Pacific southeastward to near 20N116W. The ridge is supporting moderate to fresh NW to N winds over the waters W of Baja California with locally strong winds north of Punta Eugenia. Light to gentle winds prevail between Cabo San Lucas and the Revillagigedo Islands. Seas are 6 to 8 ft in NW swell north of Cabo San Lazaro, and 6 to 8 ft in a mix of NW and S swell south of Cabo San Lazaro. Elsewhere, including the Gulf of California, light to gentle winds prevail, with 3 to 5 ft seas at the entrance of the Gulf and 2 ft or less elsewhere. Seas of 6 to 7 ft in SW swell dominate the remainder of the Mexican offshore waters. For the forecast, the surface ridge will continue to dominate the offshore forecast waters of Baja California through the week. Moderate to fresh NW to N winds W of the Baja California peninsula will continue through Sat night. NW swell moving across the Baja California offshore waters will persist through Thu. Seas of 8 to 10 ft N of Punta Eugenia will continue through Wed, then subsiding below 8 ft on Fri. Winds in the Gulf of California could increase to moderate to locally fresh Wed through Sat night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scattered moderate to isolated strong convection continues to impact the offshore waters from Costa Rica to Colombia, N of 04N and E of 89W. These storms are bringing frequent lightning strikes and likely gusty winds and locally rough seas. Exercise caution in this area. South of monsoon trough around 08N, moderate to fresh winds are noted, including the South American offshore waters. North of 07N, light to gentle winds prevail elsewhere. Seas are 6 to 8 ft across the Ecuador and Galapagos Islands offshore waters due to long period SW swell. Otherwise, seas range 5 to 7 ft across the rest of the offshore waters within long period SW swell. For the forecast, moderate to strong thunderstorms will keep impacting waters from Costa Rica to Colombia through Thu. For waters south of 07N, winds will be moderate to locally fresh through Fri. North of 07N, light to gentle winds will prevail. Long period SW swell bringing 8 ft seas in the Ecuador and Galapagos Islands offshore waters will subside later this morning. Seas of 5 to 7 ft in SW swell will persist across the Central and South American offshore waters through the rest of the week. By the weekend, winds across the rest of the area will be light to gentle with seas 4 to 6 ft. ...REMAINDER OF THE AREA... High pressure of 1035 mb, located N of the forecast area near 40N142W, extends a ridge across the waters N of 15N and W of 115W. The pressure gradient between the ridge and lower pressure along the ITCZ is forcing moderate to fresh NE to E trades N of 06N and W of 115W. Strong winds are pulsing along 12N and W of 137W. Seas are 7 to 9 ft in this area. Northerly swell is merging with the swell from the trade wind zone, with seas 8 to 10 ft N of 26N. Elsewhere south of 06N, gentle to moderate winds and seas of 6 to 8 ft in merging N and SW swell prevail W of 110W. South of the ITCZ, gentle to moderate winds prevail. Seas are 6 to 8 ft in mixed SW and SE swell. A 1006 mb low pressure near 11N107W is producing fresh to locally strong winds with seas 8 to 9 ft. For the forecast, high pressure will remain in control of the weather pattern across the area N of 15N and W of 115W through the week. This will maintain mostly moderate to fresh trade winds and moderate to rough seas along the southern periphery of the ridge, and mainly W of 130W. Strong winds will continue through today mainly W of 138W. Cross equatorial SW swell will continue to combine with northerly swell to dominate area waters through Wed before subsiding. Seas of 8 to 9 ft across the trade wind zone will begin to slowly subside by Wed, and subside below 8 ft by Fri. $$ AReinhart