The National Weather Service (NWS) Flagstaff office issued a Tornado Warning for parts of Coconino County, Arizona, on October 21. This urgent alert was put into effect at 5:28 AM MST and was scheduled to expire a short time later, at 5:45 AM MST on the same day. At the time the warning was issued, NWS Flagstaff reported that a severe thunderstorm, showing radar-indicated rotation and capable of producing a tornado, was detected near Maine. This location is approximately 14 miles west of Flagstaff, and the storm was moving northeast at a speed of 40 mph.

The primary hazards specified in the NWS warning included a confirmed tornado threat and the potential for quarter-sized hail. The basis for this critical warning was radar-indicated rotation within the thunderstorm, suggesting the conditions for tornado formation were present. The NWS detailed several potential impacts, such as flying debris, which poses a significant danger to individuals without adequate shelter. The warning also anticipated that mobile homes would likely suffer damage or be destroyed, and there was a high probability of damage to roofs, windows, and vehicles. Extensive tree damage was also listed among the likely consequences.

The geographic scope of the warning encompassed several specific locations. These included Fort Valley, Parks, Bellemont, Garland Prairie, Government Prairie, Maine, Camp Navajo, Wing Mountain, and Lava River Cave. Crucially for travelers, the warning also covered sections of major transportation arteries: Interstate 40, specifically between mile markers 176 and 187, and Highway 180, between mile markers 223 and 227.

Despite this official alert from the NWS, conflicting reports emerged from other weather monitoring platforms during the same period. A summary of tornado warning activity for Arizona published on tornadopath.com, updated at 8:04 AM on October 21, indicated that the National Weather Service had issued no tornado warnings for the state on that particular day. This presented a direct contradiction to the active warning from NWS Flagstaff.

Further adding to the potential for confusion, AccuWeather's reports as of 3:21 PM on October 21 showed no active warnings or advisories specifically for Coconino County. The discrepancy between the official NWS warning, which signals an immediate threat to life and property, and the lack of such warnings on other prominent weather tracking services, highlights a potential information gap that could affect public safety responses during severe weather events.