textproduct: Grand Junction

KEY MESSAGES

- This week will see daily afternoon thunderstorm chances, particularly along the higher terrain of western Colorado and eastern Utah.

- Localized heavy rainfall continues to pose a threat to flash flooding over burn scars and susceptible terrain.

- Daytime highs will run ~5 to 10 degrees above normal to start the week and will gradually increase through Friday.

DISCUSSION

Issued at 1219 PM MDT Mon Aug 24 2026

MOUNTAIN STORMS AND WARM TEMPERATURES:

Afternoon showers and thunderstorms continue today, although decreasing moisture will largely restrict convective activity to the higher terrain. PWATs will remain around 125 to 150% of normal through Wednesday, decreasing more during the end of the workweek. The elevated PWATs will support daily mountain convection, which also means that concerns with flash flooding and debris flows from localized heavier rainfall over newer burn scars and susceptible terrain will persist.

Today's high temperatures will be around 5 to 10 degrees above normal. Westward shifting high pressure will allow for temperatures to gradually increase by a degree or so each day through Friday.

DRIER CONDITIONS LATER THIS WEEK:

Drier conditions at the end of the workweek, coupled with increased afternoon wind gusts as a trough brings a jet streak and stronger pressure gradient to the area, could create localized critical fire weather conditions on Friday and Saturday. However, some guidance actually favors stronger moisture advection on Friday and Saturday, which decreases confidence on the specifics of where relative humidity values might fall below critical fire weather thresholds.

The anticipated pattern shift this weekend is forecast to drop high temperatures on Saturday and Sunday. Current guidance suggests this drop could bring highs down to near normal for this time of the year.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 713 PM MDT Mon Aug 24 2026

Shower activity is gradually diminishing over much of the region this evening. Winds will be light and terrain driven during the overnight hours. Cloud coverage will lighten up overnight, before some high and mid level clouds return Tuesday afternoon. Shower activity Tuesday will be mostly along the higher terrain terminals. Primary threats continue to be gusty outflows, lightning, and localized heavy rainfall.

GJT WATCHES/WARNINGS/ADVISORIES

CO...None. UT...None.