textproduct: Grand Junction

KEY MESSAGES

- Scattered to widespread storms develop this afternoon and evening with an uptick in coverage expected.

- Localized flash flooding over burn scars and steep terrain is the primary risk of storms this afternoon. Gusty winds, lightning, and small hail will also be possible.

- Hot and predominately dry conditions move in for the weekend and beyond.

DISCUSSION

Issued at 1120 AM MDT Wed Jul 29 2026

THUNDERSTORMS THIS AFTERNOON/EVENING:

A shortwave trough will move across the region today and tonight. This will provide enhanced lift and support scattered to widespread convection as it moves through. It will also help speed up storm motions compared to previous days. Despite this, localized flash flooding remains on the table if stronger and/or training storms move over steep terrain and recent burn scars. See the Hydrology section below for more information.

LATE WEEK PATTERN CHANGE:

Behind the aformentioned shortwave, dry air begins to filter back into the region. It will take a few days before residual moisture is completely scrubbed from the atmosphere, so we expect some convection Thursday and Friday with coverage decreasing each day. As things dry out, the primary threat of thunderstorms will switch from heavy rainfall to gusty outflow winds up to 50 mph.

High pressure sets up over Utah this weekend bringing hot and mostly dry conditions. Temperatures will run around 10 degrees above normal, but with less moisture in the air, you can expect more of a "dry heat" compared to what we've endured lately.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 528 PM MDT Wed Jul 29 2026

Showers and storms continue into the evening hours for some terminals. Included PROB30 and TEMPO groups to account for that threat. Primary threats include lightning, heavy rainfall, and gusty outflow winds (20-30 kts). Outflow gusts upwards of 40-50 kts have been observed with the stronger cells. Where thunderstorms are not present overnight, winds will return to a light and terrain driven regime. Cloud cover will lighten up overnight as storms clear out, but mid-level cloud development will begin again by Thursday afternoon. Storm chances will be lower in coverage Thursday, mainly confined to the higher terrain. VFR conditions are expected to prevail, but cannot rule out MVFR conditions due to visibility restrictions.

HYDROLOGY

Issued at 1130 PM MDT Tue Jul 28 2026

Scattered to widespread thunderstorms capable of producing heavy rainfall will develop this afternoon/evening, with the potential for flash flooding decreasing beyond today. Rainfall rates of 1-2" per hour will be possible, potentially even greater for brief periods of time 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...None. UT...None.