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 /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1120 AM MDT Wed Jul 29 2026

Showers and storms will begin initializing off the higher terrain beginning around 18-19Z. There continue to be chances for these storms to travel down to the valleys and impact some lower lying TAF terminals. Primary threats with these storms continue to be lightning, heavy rainfall, and gusty outflows (25-35 kts). Storm activity begins to drop off around 00-01Z this afternoon. Cloud cover begins to decrease into the overnight period before building back up Wednesday afternoon. All that said, VFR conditions are likely to prevail.

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.