At least nine tornado warnings were issued in Arizona as a strong low-pressure system brought rounds of thunderstorms, heavy rain and damaging-wind risks on Wednesday and Thursday, according to the National Weather Service and the Storm Prediction Center, the Phoenix Focal reported on October 22. No tornadoes had been confirmed. The latest warning cited in the forecast covered Coconino and Navajo counties and expired at 6:45 p.m., and at least seven warnings had been issued in northern Arizona on Wednesday morning.

Source: Phoenix Focal — Arizona storms bring nine tornado warnings and flood threat through Thursday

Downtown Flagstaff reported hail the size of golf balls, or 1.75 inches in diameter, on Wednesday, and there was also a gust to 72 mph at the Flagstaff Airport, The Weather Channel reported in its October 22 flood and severe-storms outlook. The first tornado watch was issued for northern Arizona in more than 16 years on Wednesday, the channel said. A tornado watch in northern Arizona was set to remain in effect until 6 p.m., while a severe thunderstorm watch there extended until 2 a.m. Thursday, the Focal reported.

Source: The Weather Channel (weather.com) — Flood risk, severe storms threat from California to Colorado

The Storm Prediction Center outlook showed a 5% chance of tornadoes on Thursday in parts of eastern Arizona, including areas near Show Low and Safford, and the Phoenix area and parts of central and southeastern Arizona were also under a severe thunderstorm watch through 9 p.m. Wednesday, covering Gila, Maricopa, Graham, Pinal and Greenlee counties, where storms could bring heavy rain, strong gusts and small hail, the Focal reported. On Thursday, isolated storms could again produce strong wind, hail and even a tornado across the Desert Southwest and Four Corners region, with Arizona under the greatest risk yet again, The Weather Channel said.

Source: Phoenix Focal — Arizona storms bring nine tornado warnings and flood threat through Thursday

The heaviest rainfall was forecast for northern and eastern Arizona, with flash flooding possible in mountain communities; a flood watch was in effect through Thursday evening, with additional heavy rain expected overnight into Thursday morning, the Focal reported. The Weather Channel said tropical moisture will fuel a multiday flood risk across seven states from California to Colorado, with millions under a flood watch, rainfall rates as high as 2 inches per hour, and a threat of debris flows and landslides, especially across burn scars. As much as 3 inches of rain is expected across portions of the Desert Southwest, with isolated locations up to 5 inches, and the greatest flood risk on Thursday covers much of Arizona, Nevada, New Mexico, Colorado and Utah, including Phoenix, Tucson, Las Vegas and Albuquerque, the channel said.

Source: The Weather Channel (weather.com) — Flood risk, severe storms threat from California to Colorado

Showers were expected to continue in eastern Arizona into Thursday afternoon and evening before drier air arrived, with conditions forecast to become mostly dry by Friday, the Focal reported. Drivers through northern and eastern Arizona and the Four Corners — including on I-40 and I-17 — should check current National Weather Service warnings before travelling, as watches and warnings in this system have changed through the day.

Source: Phoenix Focal — Arizona storms bring nine tornado warnings and flood threat through Thursday