Tornado warnings hit northern Arizona's Dewey-Humboldt as rare storm system sweeps Southwest

A severe storm system moved through northern Arizona on Wednesday, October 21, 2026, prompting the National Weather Service office in Flagstaff (NWS Flagstaff) to issue at least 10 separate tornado warnings over the course of the day, according to AZFamily.

One of the warnings covered Dewey-Humboldt, a town in Yavapai County, where AZFamily's chief meteorologist said a possible tornado formed Wednesday morning. Viewer-submitted video showed dark funnel clouds over the area; FOX10 Phoenix reported that the National Weather Service had not confirmed a tornado touchdown from the sighting.

A watch not seen in Arizona for years

Beyond the individual warnings, NWS Flagstaff issued a broader tornado watch in effect until 6 p.m. local time, covering northern Arizona, according to AZFamily and FOX10 Phoenix. FOX Weather, in a report carried by Yahoo News, specified that the watch covered Coconino, Yavapai, Mohave and Navajo counties.

FOX Weather reported that this was the first tornado watch issued for Arizona in roughly 16 years, while FOX10 Phoenix cited a gap back to 2010 — both sources describing the watch as highly unusual for the state. A separate severe thunderstorm watch remained in effect until 2 a.m. Thursday.

FOX Weather rated the severe-weather risk for areas including Flagstaff and Prescott at Level 3 out of 5, with hazards listed as damaging, egg-sized hail and tornadoes. The Phoenix metro area, including Glendale, Chandler and Scottsdale, was placed under a lower Level 2 risk.

Where the warnings struck

According to AZFamily's timeline, three tornado warnings were issued around 5 a.m., followed by a fourth around 8 a.m. for Prescott, Prescott Valley, the Prescott Airport, Mingus Mountain, Lynx Lake and Willow Creek Reservoir. A fifth warning covered the Jerome area around 8:30 a.m., and a sixth was issued near 9:10 a.m. for Flagstaff, Fort Valley, Mt. Elden, University Heights, Rogers Lake, A1 Mountain, Doney Park, Sunset Crater National Monument, Timberline, East Flagstaff and Wupatki Trails.

FOX Weather, in a report carried by Yahoo News, said the Flagstaff-area warning followed a severe thunderstorm the NWS detected near downtown Flagstaff at about 9:20 a.m., moving north at 45 mph. Later warnings covered Valle around 11:30 a.m. and the Show Low area around 3:30 p.m., per AZFamily.

A National Weather Service warning cited by FOX Weather (via Yahoo News) cautioned that "flying debris will be dangerous to those caught without shelter" and that "mobile homes will be damaged or destroyed."

Damage, closures and a wider regional threat

AZFamily reported storm damage in parts of Yavapai County, including Prescott and Mayer, hail damage to vehicles and windows in north Phoenix, and damage reported in the Heber-Overgaard area, though it said specific damage details remained limited as of its report. All seven Hopi tribally controlled schools closed on Thursday because of the severe weather, the outlet said.

The system extended well beyond northern Arizona. FOX Weather reported a low-end tornado risk along a corridor from Carmel, California, south to Los Angeles, along with flash-flood concerns over wildfire burn scars in Southern California. Flood watches in Arizona were extended through Thursday, and FOX Weather reported a renewed flash-flood threat in the Four Corners region on Thursday, including a Level 3 out of 4 flash-flood risk near the Ferris Fire burn scar in southeastern Colorado, where 3 to 5 inches of rain were considered possible.

FOX Weather described the event as exceptionally rare for the Southwest, noting the region typically sees severe weather during its summer monsoon season between June and September rather than in late October.

What remains unknown

As of the reports reviewed, neither AZFamily nor FOX10 Phoenix said the National Weather Service had confirmed any tornado touchdown from the Dewey-Humboldt sighting or the other warned storms; FOX10 Phoenix explicitly noted there had been no NWS confirmation that a tornado touched down. Precise damage totals and any injuries had not been detailed in the sources reviewed.