Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Oct 2 2025 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 1440 UTC. ...SPECIAL FEATURES... Tropical Storm Octave is centered near 12.5N 118.5W at 02/1500 UTC, moving west-northwest at 7 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are currently around 18 ft (5.5 m). Numerous moderate to strong convection is noted from 11N to 13N between 118W and 120W. Scattered moderate and isolated strong convection is elsewhere from 05N to 16N between 116W and 125W. A general west-northwestward motion is expected with little change in strength forecast during the next 48 hours. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Octave NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Offshore of the Southwestern Coast of Mexico: A trough of low pressure located a few hundred miles off the coast of southern and southwestern Mexico is producing a large area of disorganized showers and thunderstorms. Environmental conditions appear conducive for gradual development, and a tropical depression is likely to form by the weekend while the system moves generally west-northwestward, remaining parallel to but offshore of the southwestern coast of Mexico. Interests along the southwestern coast of Mexico should closely monitor the progress of this system. Regardless of development, expect increasing winds and seas over these waters. This system has a medium chance for tropical cyclone formation within the next 48 hours and a high chance within the next 7 days. Please read the latest TROPICAL WEATHER OUTLOOK issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIATWOEP.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 11N96W to 15N106W. It resumes from 12N122W to 10N130W. The ITCZ extends from 10N130W to 11N140W. Scattered moderate and isolated strong convection is noted from 05N to 09N between 80W and 86W, and from 05N to 15N between 88W and 107W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features for details on Tropical Storm Octave located well SW of the offshore waters, and on a trough of low pressure offshore of SW Mexico with the potential for tropical cyclone formation. Fresh to locally strong N-NE winds are noted over and downstream the Gulf of Tehuantepec. Moderate NW-N winds are west of the Baja California peninsula N of Cabo San Lazaro. Mainly light to gentle winds are across the remainder of the waters, including the Gulf of California. Seas are in the 4-6 ft range over the open waters off Mexico in mixed S-SW and W-NW swell. Seas are 3 ft or less in the Gulf of California, reaching 4 ft near the entrance of the Gulf. For the forecast, other than Tropical Storm Octave which is forecast to remain beyond the offshore waters, and the trough of low pressure offshore SW Mexico with the potential for tropical cyclone formation, moderate to fresh N-NE winds will pulse in the Gulf of Tehuantepec through early Sat, locally strong at times. Moderate to locally fresh winds will persist offshore Baja California N of Cabo San Lazaro through the remainder of the week and into Sat, locally strong near Punta Eugenia at times. New NW swell will arrive offshore Baja Cailfornia this afternoon, building seas to rough in the outer waters through Sat night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are N of the monsoon trough. Moderate S-SW winds prevail S of the monsoon trough. Seas are 4-5 ft in mixed SW and NW swells across the waters. For the forecast, mostly light to gentle winds will prevail N of the monsoon trough, except locally higher near convection. Gentle to moderate S to SW winds are expected S of the monsoon trough. Southerly swell will build slightly Fri into the upcoming weekend. ...REMAINDER OF THE AREA... Please refer to the Special Features for details on Tropical Storm Octave, and on a trough of low pressure offshore of SW Mexico with the potential for tropical cyclone formation. The 1015 mb remnant low of Post-Tropical Cyclone Narda is located near 23N129.5W. No deep convection is present with the remnant low. Moderate winds are currently in the NW semicircle. A cold front extends over the NW waters. The front has ushered in a set of NW swell, with seas in the 8-9 ft range over the NW waters. Seas are mainly 5-7 ft outside of Octave and the NW waters. Winds are mainly moderate or weaker across the open waters away from Tropical Storm Octave. For the forecast, Octave will move to 12.8N 119.3W this evening, 13.3N 120.5W Fri morning, 13.8N 121.8W Fri evening, 14.4N 123.0W Sat morning, 15.0N 123.8W Sat evening, and strengthen to a hurricane near 15.3N 124.0W Sun morning. Octave will change little in intensity as it moves to near 15.9N 122.9W early Mon. The remnant low of Narda will drift W-SW and gradually spin down, and open up into a trough later today, with associated and residual winds and seas decreasing through then. A front and associated northerly swell will impact the northern waters, spreading eastward to near Baja California through the end of the week. High pressure to the NW of the area will build southeastward into the NW waters behind this front, with moderate to locally fresh N to NE winds gradually expanding there by the end of the week into the weekend. Winds will increase to fresh to locally strong S of the monsoon trough, mainly E of 125W by the end of the week into the weekend, as an area of low pressure possibly develops into a tropical cyclone offshore of SW Mexico. These winds may build seas to rough S of the monsoon trough. Meanwhile, a new set of large southerly swell will propagate toward the equator during the upcoming weekend.