Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Oct 9 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 1550 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the Gulf of Fonseca near 13N87W to just SW of the Gulf of Tehuantepec near 14N98W to 08N120W to 08N130W. The ITCZ begins near 08N130W and continues beyond 09N140W. Scattered moderate convection is noted from 06N to 10N E of 90W and from 10N to 14N E of 94W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Disorganized showers and thunderstorms continue in association with a weak low pressure system, Invest EP99, located about 230 miles southeast of the southern tip of the Baja California peninsula. Moderate to locally fresh winds are around the low with seas to 6 ft. Scattered moderate isolated strong convection are ongoing from 20N to 23N between 105W and 109W. Meanwhile, fresh to strong NW to N winds are pulsing in the Gulf of Tehuantepec due to a locally tight pressure gradient. Seas are estimated at 6 to 9 ft there. Gentle to moderate winds prevail elsewhere over the offshore waters of Mexico. Seas are 4 to 6 ft in converging SW and NW swells, except up to 8 ft well offshore Baja California Norte in NW swell. For the forecast, slight development of Invest EP99 is possible today while it moves slowly north-northwestward to northwestward. By tonight, increasing upper-level winds and dry air should end the chances for any further development. Fresh to near gale force northerly winds will pulse in the Gulf of Tehuantepec with seas building at times to 8 to 12 ft through the next several days. Meanwhile, a ridge will remain in control of the weather pattern across the offshore waters of Baja California. This will produce moderate NW winds N of Punta Eugenia and slight to moderate seas through Sun night, briefly fresh to strong near Sebastian Vizcaino Bay Sat night. Seas will peak around 8 ft in NW swell north of Punta Eugenia through tonight, then possibly again there late in the weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW to W winds are found north of 10N offshore Nicaragua and El Salvador, with moderate to fresh W to NW winds offshore Guatemala due to a gap wind event to the west over the Gulf of Tehuantepec. Moderate to fresh SW winds prevail from offshore Colombia to Costa Rica, with moderate SE to S winds from offshore Ecuador to the Galapagos Islands. Seas are 4 to 6 ft across the offshore waters in mainly S to SW swell, except NW swell offshore Guatemala due to the Tehuantepec winds. For the forecast, mainly gentle to moderate southerly winds will prevail across the offshore waters, pulsing to moderate to fresh from the Papagayo region northward late tonight onward. Meanwhile, moderate to locally fresh winds could occur offshore Guatemala through today due to the influence of the Tehuantepec gap wind event. This gap event will also act to build the seas offshore Guatemala through the remainder of the week into the weekend. Moderate seas in long period S to SW swell are expected across the area. ...REMAINDER OF THE AREA... A couple of weak surface troughs are north of the monsoon trough with some isolated showers near each feature. NW swell is moving across the Baja California California Norte offshore waters and adjacent subtropical open waters. This is supporting seas of 8 to 9 ft N of 26N and E of 127W where also moderate to locally fresh N to NE winds are ongoing. Otherwise, a broad ridge extends from NW to SE across the waters north of the monsoon trough with mainly gentle to moderate trades. Remnant 7 to 8 ft seas in NW swell are across the NW waters, aided by previous fresh NE winds. Gentle to moderate southerly winds are south of the monsoon trough. Seas are mainly 5 to 7 ft across the remainder of the open waters. For the forecast, high pressure will continue to dominate the waters north of the monsoon trough through the remainder of the week and weekend while the weak surface troughs gradually push west of 140W. Mainly gentle to moderate winds will prevail across the open waters during these days. Meanwhile, the remnant northerly swell over the NW waters will gradually decay to less than 8 ft by Thu night. Southerly swell will move across the southern waters by late tonight, bringing 8 to 9 ft seas as far north as 07N between 100W and 125W. Looking ahead, a new set of NW swell with seas of 8 ft or greater may spread southeast of 30N140W Fri night through Sat, decaying thereafter. Yet another set of NW swell may reach 30N140W Sun night.