Vance became a 90-mph hurricane 455 miles south-southwest of Acapulco, with life-threatening surf headed for Mexico

Hurricane Vance had maximum sustained winds of 90 mph, and its center sat about 455 miles south-southwest of Acapulco, Mexico, when the National Hurricane Center issued Advisory Number 9 at 9:00 a.m. CST (1500 UTC) on Oct. 23. The center was near 10.7 degrees north and 102.1 degrees west, moving northwest at 5 mph over open water. Forecasters expect swells from the storm to reach the southern and southwestern Mexican coast over the weekend and into the following week.

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The same advisory described a storm that was organizing quickly. Hurricane-force winds extended up to 35 miles from the center and tropical-storm-force winds up to 205 miles. The estimated minimum central pressure was 979 millibars, while a NOAA drifting buoy had earlier reported 988.5 millibars. No coastal watches or warnings were in effect, which fits a storm still hundreds of miles offshore and drifting slowly rather than racing toward land.

Advisory Number 9 and the figures it gave

The 90 mph and 455-mile figures come from the hurricane center’s public advisory, numbered 9 and timed 9:00 a.m. CST on Oct. 23. It said winds had increased to 90 mph with higher gusts and placed the center about 455 miles (730 kilometers) south-southwest of Acapulco. It also called for steady to rapid strengthening through Saturday morning, Oct. 24, followed by slow weakening on Saturday night and Sunday, with a slow north-northwest or northwest track through the weekend. Advisory 9 was still the version posted on that page when it was last read for this article on Oct. 24, so a later numbered advisory may have changed the exact figures.

Advisory 9 gave 3:00 p.m. CST as the time of the next update, and every number above describes the storm at 9:00 a.m. on Oct. 23. A hurricane that is strengthening this quickly can look quite different within hours, so the 90 mph reading is a snapshot from that morning and not a standing description of the storm.

Discussion Number 10 and the major-hurricane forecast

The companion technical text, Forecast Discussion Number 10, was written by forecaster Beven at 3:00 p.m. CST on Oct. 23 and already put Vance’s initial intensity at 90 knots, or 105 mph, above the 90 mph in the morning advisory. Beven’s forecast peaks the storm at 105 knots (120 mph) at 12 hours and trims it to 100 knots at 24 hours, and the discussion says “This should soon bring the current intensification to a halt,” after describing a storm that had become better organized. It describes a weak mid-level ridge over eastern Mexico and the eastern Pacific as the feature steering the storm, which is consistent with the slow motion the advisory reported.

Those numbers matter because of where they sit on the Saffir-Simpson Hurricane Wind Scale. A Category 1 hurricane has sustained winds of 74 to 95 mph, so the 90 mph in Advisory 9 was the top of that band. Category 3, the first major-hurricane rung, starts at 111 mph, and the 120 mph peak in Discussion 10 would put Vance in Category 3, which spans 111 to 129 mph. The advisory’s statement that Vance is forecast to become a major hurricane by Saturday morning therefore means a gain of at least 21 mph from the 90 mph reading, and the discussion’s 12-hour peak would clear that bar by 9 mph. All of it remains a forecast, subject to change in later advisories.

Swells, rip currents and the Mexican coast

Vance’s hazard for land is the water it pushes outward. Advisory 9 said swells from the hurricane were expected to reach southern and southwestern Mexico this weekend and continue into next week, “likely to cause life-threatening surf and rip current conditions.” Because the center is far offshore, beaches can look ordinary while the surf zone becomes dangerous, a pattern the National Weather Service describes on its rip current safety page: rip currents often form on calm, sunny days when the water looks harmless, and swimming where lifeguards are posted is the main protection. That page cites the U.S. Lifesaving Association’s estimate of a 1 in 18 million chance of drowning at a beach with lifeguards.

The storm’s quick growth is worth a note. An Associated Press report carried by CP24 on Oct. 21 said Tropical Storm Vance had formed about 520 miles south of Acapulco with winds of about 40 mph, according to the hurricane center, and posed no threat to land. Two days later the advisory cited above had winds of 90 mph, a 50 mph gain, and the center had come only about 65 miles closer to Acapulco, a sign of how slowly the system has been moving. The same slow motion means swells can keep radiating toward Mexico for days even after the center begins to weaken.

Anyone with beach or boating plans on the Mexican Pacific coast can follow the numbered advisories and discussions on the National Hurricane Center’s current storms page, where each new package replaces the figures quoted here with the center’s latest position and intensity.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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