Month’s worth of rain forecast to wash out Labor Day weekend plans in West

1 of 2 | Rain is rarely an odds-on favorite weather forecast for Las Vegas (pictured, 2018), but chances are flood-potential rains will soak the resort city and many other areas of the U.S. West this Labor Day weekend, forecasters say. File Photo by James Atoa/UPI | License Photo

Whether it’s extreme heat or dangerous flash flooding, residents across portions of the West haven’t been able to catch a break this summer — and as the unofficial end to summer nears, yet another potentially hazardous event is expected to unfold.

A slow-moving storm rolling into the West will arrive just in time for the extended Labor Day weekend, bringing a major shift in the weather for millions of people across the region.

A surge of moisture originating from the Pacific Ocean will fuel widespread rain and thunderstorms from the deserts of Arizona and Southern California northward through the Great Basin and Rockies. This can result in a heightened flash flooding risk, which can be further elevated as many Americans head outdoors during a time often considered to be the unofficial end of the summer season.

Vacationers who are planning a trip to one of the many national parks, including Grand Canyon, Yosemite, Zion, Bryce Canyon and many others, should keep an eye on the sky as conditions can change rapidly during the afternoon and evening hours as thunderstorms build.

In addition to the flooding threat, severe weather is also expected late in the day Friday across portions of the Southwest.

Las Vegas, Phoenix and Salt Lake City could all face the risk of flash flooding, frequent lightning and damaging wind gusts that can kick up dust storms and topple over trees and some structures.

As the weekend progresses, some cities across the West could end up experiencing a month’s worth of rain in a matter of hours. September typically features dry conditions for many, so the historical average amount of rainfall throughout the month is typically low.

In Las Vegas, the historical average for rainfall in all of September is 0.32 of an inch. In Salt Lake City, the historical average is 1.06 inches. Both cities have the potential to exceed these rainfall benchmarks over the Labor Day weekend.

The corridor of the heaviest rain and thunderstorms will gradually shift northward as the weekend progresses, and some locations, such as Salt Lake City, could face multiple days of flooding storms.

By Sunday, the rain and thunderstorms are predicted to extend into parts of Idaho and Wyoming.

Many locales across the Southwest will dry out by Labor Day on Monday. Conversely, the central and northern Rockies can be in line for another round of drenching rainfall.

Looking beyond Labor Day weekend, dry conditions are expected across a majority of the West later next week.