A deep tropical moisture plume is driving heavy rain, flash‑flood warnings and the first tornado watch in northern Arizona in 16 years.
Key points
- Tropical moisture will keep the Southwest vulnerable to flash flooding and mudslides through Friday.
- Arizona sees its first tornado watch in 16 years, with isolated tornadoes possible in New Mexico on Friday.
- Higher elevations of the Colorado Rockies could receive the first notable snow of the season, potentially benefiting ski resorts.
- Travelers to national parks and mountain passes should monitor updates and heed any flood or snow warnings.
Meteorologists say a moist air mass moving into the Southwest will keep rain and flood threats active through Friday, with nearly three million people under flood watches across the Four Corners region, California and parts of the High Plains.
Severe thunderstorms have already produced large hail—up to 1.75 inches in diameter—gusts of 72 mph at Flagstaff Airport and the first tornado watch for northern Arizona in more than a decade, prompting a second watch for eastern Arizona and western New Mexico.
Widespread rain and flash‑flood danger
Flash‑flood warnings are in effect for southern Utah, where the town of Hurricane has ordered evacuations, and officials warn that saturated soils could trigger mudslides on recent burn‑scar areas, slot canyons and arroyos.
Snow is also possible at higher elevations. The Colorado Rockies may see the season’s first significant snowfall, with isolated peaks potentially receiving one to two feet, while lower elevations could still experience rain that quickly turns to snow.
Isolated tornadoes and hail reported
Rainfall totals of up to five inches are forecast for New Mexico and southern Colorado by week’s end, enough to spark flash flooding, while the Texas Panhandle to southeastern South Dakota could see up to three inches of rain.
Reader questions
What areas are currently under flood watch?
Nearly three million people across the Four Corners region, parts of California, Arizona, New Mexico and the Southern High Plains are under flood watches, according to the latest weather maps.
When was the last tornado watch issued in northern Arizona?
The most recent tornado watch for northern Arizona was issued on Wednesday, marking the first such watch in more than 16 years.
Will the Colorado Rockies see snow this week?
Forecasters expect isolated snowfall at higher elevations of the Colorado Rockies, with some peaks possibly receiving one to two feet of snow, while lower elevations may still see rain.
Source: weather.com