Fox News Weather Center

Drenching Thunderstorms to Dot Western US Through the Weekend, Erase October Warmth

A storm system that brought rain and thunderstorms across the Desert Southwest late this week will target the Rockies this weekend with potentially flooding downpours.

This storm system moved onshore on Thursday, spreading rain and locally drenching thunderstorms across parts of California and Nevada.

Heavy rain led to flooding and mudslides across Southern California on Thursday.

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According to AccuWeather Western U.S. Expert Ken Clark, "Similar weather can be expected on Friday as the low will be near the Inland Empire, except precipitation will occur even farther north in Nevada and Utah and over all of Arizona and even western New Mexico."

Storms will depart the western portions of California, including Los Angeles, San Diego and Long Beach.

By the weekend, this storm system will combine forces with another storm system moving into the West Coast and produce rounds of thunderstorms across the Rockies through the weekend.

While these thunderstorms will be spotty in nature, any thunderstorm can lead to flash flooding.

According to AccuWeather Meteorologist Dan Pydynowski, "Some of these thunderstorms could be rather slow moving and cause flash flooding and mudslides across roadways that can slow or delay travel."

Wet weather will target areas such as Phoenix and Flagstaff, Arizona; Albuquerque and Gallup, New Mexico; Las Vegas and Reno, Nevada; Salt Lake City and Cedar City, Utah; Durango and Grand Junction, Colorado; and Boise and Pocatello, Idaho.

Drivers traveling along interstates 15, 17, 40, 70, and 80 should be prepared for spotty downpours and slow down to reduce the risk of hydroplaning.

Any downpour could ruin any high school or college football games this weekend.

Use ​AccuWeather Minutecast® to view the minute-by-minute precipitation forecast for your area.

"Campers and hikers in areas such as Zion National Park will need to stay alert and be aware of the threat for storms this weekend that can produce lightning, heavy rainfall and flash flooding," Pydynowski said.

This storm system will not only produce locally heavy thunderstorms, but also bring an end to the warmth that has been persistent across the West since the beginning of October.

Much of the western U.S. has had temperature departures between 5 and 10 degrees above normal this month. Several cities have set multiple record-high temperatures this month.

Temperatures next week will return to near-normal values across much of the West.

According to AccuWeather Senior Meteorologist Alex Sosnowski, "Rainfall has been above average every month since the start of the year in Las Vegas, and total rainfall has been above average since Jan. 1 for many areas outside of California."

"Even in drought-stricken Southern California, rainfall has been above average since the middle of the summer," he added.

While this rain will not put a dent in the significant drought across the western U.S., significant precipitation is expected to occur across much of the southwestern U.S. this winter.