Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Apr 18 2026 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from northwest Colombia southwestward to 07N77W to 08N86W to 05N100W to 05N110W, where it transitions to the ITCZ and continues to 06N121W to 05N131W and to beyond 05N140W. Scattered moderate to isolated strong convection is within 120 nm south of the ITCZ between 118W-125W. Scattered moderate convection is from 02N to 06N between 85W-92W, and within 30 nm south of the ITCZ between 132W-136W. A second ITCZ extends from 01S88W to 01S110W to 02S120W to 03S130W and to 02S140W. Scattered moderate convection is within 180 nm north of the ITCZ between 90W-104W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1022 mb high pressure is centered near 32N133W, with a ridge axis extending southeastward to 28N127W and to near 20N116W. High pressure covers the area north of about 16N and west of 115W. The pressure gradient between the ridge and lower pressures over Mexico is supporting mostly moderate northwest winds west of the Baja California Peninsula, except for fresh to locally strong northwest winds near Cabo San Lucas. Winds are gentle to locally moderate across the Gulf of California. Elsewhere over the Pacific, winds are moderate or weaker in speeds. Seas are 5 to 7 ft in northwest swell over the waters northwest of Cabo Corrientes per latest altimeter satellite data, 5 to 6 ft in south swell over the Pacific to the southeast of Cabo Corrientes, 1 to 3 ft in the Gulf of California, except for seas of 3 to 5 ft in the southern section and slightly higher seas of 5 to 6 ft in long-period south swell at the entrance to the Gulf. For the forecast, fresh to locally strong northwest winds will occur near Cabo San Lucas this morning. Northwest swell west of Baja California Norte will subside this morning. Otherwise, rather quiet conditions will remain over the Mexican offshores through the weekend. Looking ahead, high pressure building over the Gulf of America is expected to induce a strong to near gale force Tehuantepec gap wind event beginning Sun night into Tue. Brief gusts to gale-force may occur with this event. Meanwhile, a set of northwest swell will move through the waters west of Baja California Norte late Tue before it subsides Wed and Wed night as it moves through the rest of the waters west of the peninsula. Seas are expected to peak to 8 or 9 ft with the swell. Otherwise, high pressure will dominate the general weather pattern into the middle of next week and support moderate to fresh winds across the area. ....OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast winds are in the Gulf of Papagayo region as indicated by a recent scatterometer satellite data pass. These winds reach westward to near 87W. Moderate north to northeast winds are in the Gulf of Panama, and reach southward to near 05N. Elsewhere, winds across the Central American and equatorial waters are gentle or weaker. Seas over the forecast waters are 4 to 6 ft in long-period south to southwest swell. Numerous to isolated strong convection is present from 02N to 08N between 86W and 92W. Scattered moderate to isolated strong convection is occurring from 03S to 02S between 84W and 88W. Isolated showers are in the vicinity of the Galapagos Islands. For the forecast, winds will pulse to fresh speeds across the Gulf of Papagayo into early this afternoon. Otherwise, rather tranquil conditions are expected to remain over the Central American and the equatorial waters through early next week. ...REMAINDER OF THE AREA... High pressure of 1022 mb is analyzed north of the area at 34N132W, with a ridge extending southeastward to 28N127W and to near 20N116W. A weak pressure gradient between the ridge and lower pressures associated to the ITCZ is allowing for only moderate to locally fresh northeast trades over forecast waters. Seas are 5 to 7 ft in mixed swell. No additional deep convection is occurring away from the surface trough/ITCZ. For the forecast, little change is expected in the winds during the next few days. Otherwise, little change in the seas are also expected through the rest of the weekend. Looking ahead, a cold front is expected to reach the northwest part of the discussion late Sat into early on Sun. The cold front will move southeastward while gradually weakening and accompanied by moderate northwest winds and large northwest to north swell. The swell should reach near 20N and west of 120W by late Tue night. Seas peaking to around 12 ft are expected with this set of swell.