textproduct: Grand Junction

KEY MESSAGES

- PM showers and storms continue to highlight the forecast today and tomorrow, continuing through the overnight hours in some locations.

- Storms will be capable of producing flash flooding, especially over burn scars and steep terrain.

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

DISCUSSION

Issued at 1121 AM MDT Tue Jul 28 2026

WARM WITH PM STORMS THROUGH WEDNESDAY:

With a stagnant weather pattern in place, conditons remain largely unchanged today. Scattered afternoon/evening showers and storms develop once again, with heavy rainfall (flash flooding) being the primary threat due to slow storm motions. Lightning, small hail, and gusty outflow winds up to 45 mph will also be possible. The CAMs support isolated convection contiuing throught the overnight hours, similar to what we saw early this morning.

Tomorrow, a shortwave trough will move through the region. This will provide enhanced lift and support scattered to widespread convection as it moves through. It should also help speed up storm motions, but localized flash flooding can't be ruled out over burn scars and other sensitive terrain.

LATE WEEK PATTERN CHANGE:

Behind the aformentioned shortwave, dry air beings 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 decreaseing 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 WEDNESDAY/

Issued at 1121 AM MDT Tue Jul 28 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 slow-moving thunderstorms capable of producing heavy rainfall will develop each afternoon through at least midweek. 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.