Heavy Rain and Flood Risk Target Western Colorado by Friday

Western Colorado’s string of warm, quiet days is about to end.

The National Weather Service in Grand Junction says a new storm system will arrive late this week, bringing widespread rain, thunderstorms, and a sharp drop in temperatures.

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From Heat to Storms

Through Wednesday, temperatures are running about five degrees above normal for early September.

That will change quickly as moisture moves into Utah and Colorado by Thursday night and Friday, opening the door for unsettled weather heading into the weekend.

Flash Flooding a Big Concern

Moisture levels are expected to spike to nearly 150% of what’s normal for this time of year.

That means storms could drop heavy rain in a short amount of time, raising the risk of flash flooding.

Burn scars from recent wildfires are especially vulnerable, and the National Weather Service warns that “training storms” (where heavy downpours repeatedly hit the same area) could lead to flooding or even debris flows.

On Thursday, storms are most likely south of I-70, especially over the San Juan Mountains.

By Friday, showers and thunderstorms are expected across much of western Colorado and eastern Utah. Gusty winds and dangerous lightning will also accompany some storms.

Weekend Outlook

The unsettled weather is expected to stick around through the weekend, keeping temperatures cooler than average with frequent clouds and rounds of rain.

Forecasters are also watching the remnants of Tropical Storm Lorena in the Pacific. If that system steers extra moisture into the Southwest, rainfall totals could be even higher.

Read More: When is the Best Time to See Fall Colors in Colorado?

By early next week, drier air looks set to return, bringing back sunnier skies and warmer afternoons.

But until then, keep the umbrella handy and stay alert to changing conditions—especially if you’re traveling, hiking, or camping near mountain roads and canyons.