Rough weather is forecast in the West as heavy rains, gusty winds and mountain snow descend on the region through the weekend.
The storm is more typical of November, but meteorologists said in a report that it will already affect areas from the Rockies to the Great Basin to the Southwest.
Heavy downpours and thunderstorms may result in flash floods across Montana, Wyoming, Idaho, Utah, New Mexico and Colorado.
"Hail and damaging winds will be the primary threats with these storms, but an isolated tornado cannot be ruled out," AccuWeather meteorologist Brett Rathbun told reporters.
Total rainfall could also exceed the September average in various locales.
Rain may pose a danger to lower terrains, but snow is expected on higher ground. Accuweather senior meteorologist Michael LeSeney said snow will level from 8,000 feet in Wyoming to 10,000 feet in Colorado.
"There may be enough snow in the highest passes Friday night to make roads snow covered and icy," LeSeney explained.
