textproduct: Grand Junction

KEY MESSAGES

- Warm overnight lows and triple digit highs for portions of eastern Utah and western Colorado are expected through Tuesday morning. The Heat Advisories remain in place.

- Afternoon and evening showers and storms will continue thanks to ample moisture and daytime heating.

- Slow storm motions will allow heavy rain under the stronger cells. Small hail and gusty outflow winds will also be possible.

- Watch out for flash flooding and debris flows in vulnerable terrain, especially for areas near and downstream of burn scars.

DISCUSSION

Issued at 911 PM MDT Sun Jul 26 2026

High pressure and ample moisture remain in place which means the running forecast remains largely the same...afternoon and evening convection. Slow storm motions remain in the forecast so, as we've seen over the last several days, the stronger showers and storms will cause plenty of heavy rain. Those areas susceptible to flooding will remain under the gun as will burn scars like the Babylon, Ferris and Gold Mountain burn scars. Outside of the rain, gusty outflow winds will also be possible with gusts of 40 to 50 mph not out of the question. To round it out, lightning will be common with some small hail also possible. The CAMs are hinting at a slight downturn in convection tomorrow and Tuesday but not sold on those solutions, however, as CAPE, instability and available moisture remains high across the CWA.

Highs remain anywhere from 5 to 10 degrees above climatological norms with 100s still in the forecast for many lower elevations. Overnight lows will drop, obviously, but still remain above normal and without much relief, the going Heat Advisory remains in effect for the Grand Valley and Lower Yampa River Basin through Tuesday morning.

Looking ahead, a shortwave is progged to move across the area Wednesday and if this should occur, some stronger thunderstorms will be possible with large hail and/or strong outflow winds. Keep an eye on the latest forecast. After that, high pressure may build in to our west. Flow around the high will cause moisture to slowly decrease which will temper convection across the region.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1132 PM MDT Sun Jul 26 2026

Outflow boundary forced showers and isolated thunderstorms have better coverage this evening than days past and should linger well into the early morning hours. Impacts are expected to minimal however with just small probability of light rain in the TAF forecast at a few sites. Otherwise convective debris clouds linger through sunrise then we do it all over again tomorrow with another round of showers and thunderstorms. Gusty winds will be the main threat though there remain a very small probability of MVFR if a storm moves directly over the airfield.

HYDROLOGY

Issued at 1224 PM MDT Sat Jul 25 2026

Scattered thunderstorms capable of producing heavy rainfall will develop each afternoon through the next week. Rainfall rates of 1-2" per hour will be possible with stronger storms. These rates could lead to flash flooding and debris flows, especially over steep terrain and recent burn scars. Saturated soils from consecutive days for rainfall will increase the potential for flash flooding as well.

As a reminder: Keep an eye on our forecasts and stay tuned for updated hydrology alerts if visiting or if you reside near terrain vulnerable to flash flooding and/or debris flows. Dry creeks and arroyos can fill quickly and without warning from storms miles away.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Heat Advisory until 6 AM MDT Tuesday for COZ001-006. UT...Heat Advisory until 6 AM MDT Tuesday for UTZ022-024-027-029.