Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Sep 16 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 0600 UTC surface analysis and satellite imagery through 0820 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure building over southern Mexico and the eastern north Pacific monsoon trough will support strong to near-gale force N to NE gap winds across the Gulf of Tehuantepec today and Thu, and will reach minimal gale force overnight tonight and briefly Thu night. Rough seas will accompany these gap winds. ...TROPICAL WAVES... The axis of a tropical wave is near 108W from 02N to 17N, moving west at 10 to 15 kt. Nearby convection is discussed in the ITCZ/monsoon trough section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 08N95W to 1007 mb low pressure near 15N126W, then from 13N130W to beyond 11N140W. Scattered moderate convection is noted from 05N to 10N between 85W and 95W, from 10N to 15N between 105W and 115W, from 12N to 15N between 122W and 128W, and from 09N to 12N between 135W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section above for more on a gale warning in the Gulf of Tehuantepec. A recent scatterometer satellite pass confirmed fresh to strong N to NE gap winds across the Gulf of Tehuantepec. 6-8 ft likely accompany these winds. Scattered showers and thunderstorms are active near weak low pressure over the central Gulf of California. Associated moderate to fresh winds are over the northern Gulf of California. Gentle to moderate winds and 4-7 ft are noted elsewhere, except 1-3 ft in the central and southern Gulf. For the forecast, please see the Special Features section for information about the gale warning in the Gulf of Tehuantepec. Elsewhere, fresh to locally strong winds associated with the low pressure over the central Gulf of California will persist mainly over the northern Gulf through tonight. Gentle to moderate breezes and moderate seas will persist elsewhere. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong easterly winds, and moderate seas, prevail across the Gulf of Papagayo region, extending downstream to near 90W. Moderate to fresh winds extend downstream from the Gulf of Papagayo to the outer offshore waters of El Salvador and Guatemala. Elsewhere, moderate or weaker winds and moderate seas are noted. For the forecast, the pressure gradient between a ridge north of the area and the eastern north Pacific monsoon trough will support pulsing fresh to occasionally strong easterly winds and moderate to rough seas across the Papagayo region through mid week, then pulsing to moderate to fresh thereafter. Moderate winds and seas will prevail elsewhere. ...REMAINDER OF THE AREA... Scattered showers and thunderstorms remain active within 90 to 120 nm to the southeast of a 1007 mb low pressure near 15N126W, the remnants of T.D. Fifteen-E. The low pressure is becoming a little more disorganized as it moves to the W-SW at 10 kt. A scatterometer satellite pass from around 0530 UTC indicated fresh to strong winds within 120 nm to the northeast of the center. Concurrent altimeter satellite data showed a broad area of rough seas north of the low pressure. This is all part of a larger area of fresh to strong winds and rough seas between the low pressure and the subtropical ridge north of the area, reaching from 14N to 24N west of 120W. Farther south, cross-equatorial SW swell to 8 ft is reaching as far north as 04N between 110W and 125W. Gentle to moderate winds and 4-6 ft combined seas in mixed swell are noted elsewhere. For the forecast, even as remnant low Fifteen-E dissipates today, a broad area of fresh to strong NE to E winds and moderate to rough seas in N swell will persist through the remainder of the week from 15N to 25N west of 125W between the remnant trough and the subtropical ridge to its north. The southerly swell south of 03N will subside below 8 ft by this evening.