textproduct: Grand Junction

KEY MESSAGES

- Showers and storms will develop each afternoon/evening for the foreseeable future.

- Heavy rain remains the primary threat of storms across the region. Gusty outflow winds and hail are likely in stronger cells as well.

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

DISCUSSION

Issued at 1007 PM MDT Sat Jul 25 2026

High pressure over the region will dominate the forecast for the next week. Expect little change in the "rinse-and-repeat" forecast with slow moving afternoon and evening showers and thunderstorms developing on the higher terrain and a few possibly moving off the terrain into the lower valleys. This moisture with pwats around an inch is trapped under the high with no flow aloft to push it out of the region. Skies clear overnight under the subsidence of the high to allow strong diurnal heating after sunrise leading to cu popping by late morning and conditions becoming convective by about noon. Look for the subsidence under the high to stifle the convection limiting chances for strong thunderstorms at least through Tuesday, but, besides the typical lightning threat, the regime favors slow moving storms that threaten possible localized heavy rain that may produce flash flooding on recent fire scars and steep terrain. You'll want to stay up on the forecast and be aware of your surroundings if you'll be out in the hills this week.

For the latter half of the week, an upper level trough dips south far enough to bring the right entrance region of a few weak jetstreaks over the region, especially the northern areas. Though the upper-level dynamics will be weak, this combined with the strong diurnal heating may be enough to kick off a few strong thunderstorms with possible large hail and stronger outflow gusts. Stay tuned for more detailed updates over the next few days. Under this high pressure over the region, temperatures will stay five to ten degrees above normal for the first half of the week, cooling a few degrees later in the week as the jet dips south.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1138 AM MDT Sun Jul 26 2026

Afternoon thunderstorms are expected to develop within the next 1-2 hours, with gusty outflow winds and moderate to heavy rain expected as the main impacts. Heavy rain could lead to periods of MVFR conditions, although VFR conditions will prevail. Convection should taper off by 06z, with lingering scattered to broken skies and light, terrain driven winds through 15z tomorrow morning.

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.