Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Oct 9 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 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Priscilla is centered near 23.8N 114.7W at 09/1500 UTC, moving north-northwest at 7 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are around 23 ft. Infrared and water vapor satellite imagery shows that Priscilla continues to lose deep convection, and weakens a little more. Priscilla is moving toward the north-northwest. A turn toward the north is anticipated later today and tonight. On the forecast track, the center of Priscilla is expected to move parallel to, but offshore of, the coast of Baja California Sur. Weakening is forecast, and Priscilla is expected to become a post-tropical cyclone by Friday. As Priscilla moves off the west coast of Baja California, up to an inch of rain is expected across the Baja California peninsula. For the southwestern United States, 2 to 4 inches of rain, with local storm total maxima to 6 inches, are expected across portions of central and northern Arizona, southern Utah, and southwest Colorado through Saturday. Flash flooding is likely in portions of central Arizona, with scattered areas of flash flooding expected across the remainder of Arizona, southern Utah, southwest Colorado, and far northwest New Mexico. Large swells generated by Priscilla are affecting the Pacific coast of Baja California Sur as well as portions of coastal southwestern and west-central Mexico. These swells are likely to cause life- threatening surf and rip current conditions, in addition to some coastal flooding. Please consult products from your local weather office. Octave becomes a post-tropical cyclone, and the last advisory was issued on this system by the National Hurricane Center at 09/1500 UTC. At this time, Post-Tropical Cyclone Octave is centered near 17.7N 110.5W, moving east-northeast at 15 kt. This motion will continue until the system dissipates into an open trough later today. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently around 12 ft. No significant convection. Octave will dissipate this evening. A Tropical Depression forms off the coast of SW Mexico this morning. At 09/1500 UTC, Tropical Depression Seventeen-E is centered near 16.2N 100.8W, moving west-northwest at 12 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently around 10 ft. Numerous moderate to strong convection is noted from 13n to 18.5n between 100W and 105W. The depression is moving toward the west- northwest, and this general motion is expected to continue through early Friday. A turn toward the northwest is expected by late Friday, followed by a northward turn by early Sunday. On the forecast track, the center of the depression is expected to move parallel to the southwestern coast of Mexico through Friday and then be near southern Baja California Sur Saturday and Sunday. Some strengthening is forecast through Friday, but weakening is likely over the weekend. Outer bands from the tropical depression will bring heavy rain to portions of southwestern Mexico through Saturday. Across coastal portions of Oaxaca, Guerrero, Michoacán, Colima, and Jalisco, rainfall amounts of 2 to 4 inches are expected, with local amounts of 6 inches or more in Guerrero and Michoacán. This rainfall will bring a risk of flash flooding, especially in areas of higher terrain. Moisture from the tropical depression will bring the potential for additional heavy rainfall over portions of the Southwest U.S. early next week. Swells generated by the depression are expected to spread westward along the southwestern coast of Mexico through Friday and reach southern Baja California Sur on Saturday. Please consult products from your local weather office. 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 Priscilla, Octave and Tropical Depression Seventeen-E NHC Forecast/Advisories and Public Advisories at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N85W to 16N98W, then resumes SW of Priscilla near 15N117W to 10N134W. The ITCZ continues from 10N134W to beyond 09N140W. Aside from the convection associated with the tropical cyclones, scattered moderate to isolated strong convection is noted from 05N to 10N between 80W and 90W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for details on Tropical Storms Priscilla, Post-Tropical Cyclone Octave, and recently upgraded Tropical Depression Seventeen-E for more details. The offshore waters of Mexico continue to be impacted by the tropical cyclone activity described above. Dangerous marine conditions are present in the waters offshore Baja California Sur, including the entrance to the Gulf of California, and the waters near the Revillagigedo Islands due to both Priscilla and Octave. Farther south, roughly between Acapulco and Cabo Corrientes, there is a large area of numerous showers and thunderstorms associated with Tropical Depression Seventeen-E. Outside the direct influence of the tropical cyclones, moderate to locally fresh northerly winds and moderate to rough seas are noted elsewhere across the Baja California offshore waters. Light and variable winds and slight seas dominate the N and central Gulf of California. For the forecast, Tropical Storm Priscilla will move to 24.8N 115.1W this evening, weaken as a post-tropical cyclone near 25.9N 115.3W Fri morning, 26.7N 115.2W Fri evening, 27.3N 114.8W Sat morning, and dissipate Sat evening. Tropical Depression Seventeen-E will strengthen to a tropical storm near 16.8N 102.6W this evening, move to 18.1N 105.1W Fri morning, 19.8N 107.8W Fri evening, 21.4N 109.9W Sat morning, weaken to a tropical depression near 23.3N 111.0W Sat evening, and 25.5N 111.2W Sun morning. Seventeen-E will become a remnant low as it moves to near 29.2N 110.7W early Mon. Marine conditions are expected to finally improve over the Mexican offshore waters early next week once all three systems pass or dissipate. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A recent scatterometer satellite pass captured moderate to locally fresh southerly winds south of the monsoon trough. A long period southerly swell is producing seas of 5 t 8 ft across these waters. Light to gentle winds and moderate seas prevail elsewhere. For the forecast, little change is expected in the weather pattern across most of the region for the remainder of this week and into the weekend under a weak pressure gradient. The southerly swell will gradually subside into the upcoming weekend. ...REMAINDER OF THE AREA... Please refer to the Special Features section for details on Tropical Storms Priscilla, Post-Tropical Cyclone Octave, and recently upgraded Tropical Depression Seventeen-E for more details. Outside of the influence of the tropical cyclones, a weak high pressure dominates the remainder of the eastern Pacific forecast waters. A weak 1015 mb low pressure system is analyzed near 22N138W, but no significant weather, winds or seas are associated with this feature. Moderate to locally fresh southerly winds and moderate to locally rough seas are occurring south of the monsoon trough. Elsewhere, light to gentle winds and moderate seas are prevalent. For the forecast, high pressure should build across the waters N of the monsoon trough/ITCZ in the wake of the tropical cyclones during the weekend into early next week. The rough seas in southerly swells over the southern waters will gradually decay into the upcoming weekend. A new set of northerly swell, bringing rough seas is forecast to propagate into the N-central waters by the end of the weekend into early next week.