textproduct: Grand Junction

KEY MESSAGES

- Near-record heat is expected to continue for western Colorado and eastern Utah this through Monday.

- Daytime highs for the lower elevations are forecast to run between 100F and 106F. Consider limiting time outdoors during the heat of the day.

- Moisture returns to the region this week. Afternoon storms are possible each day with coverage increasing as the week progresses.

DISCUSSION

Issued at 1203 PM MDT Sun Jul 12 2026

MOISTURE MOVING IN:

The center of the high pressure will continue to move northeast into the Dakotas today which will allow for easterly flow to pull in some moisture across the Four Corners region. Dew points climb into the 40s across southwest Colorado, enough to support isolated to scattered thunderstorms this afternoon.

Throughout the week ahead, a weak high circulation remains in place across northern Colorado into Wyoming with the main plume of moisture arcing across SoCal, Nevada and western Utah. Our forecast area will be under an easterly flow regime due to the position of the high pressure. Moisture will gradually increase throughout the week, and while not substantial, dew points will climb into the 40s and 50s for some locations. Storms will initially feature primary threats of gusty outflow winds up to 40-50 mph and lightning, with increasing chances of wetting rain and heavier rain rates by mid to late week. This is when burn scar flash flooding will become our primary concern.

Due to easterly flow aloft, storms this week will track to the west, opposite of what we see most days. This changes where storm development will be favored and how storms behave downwind of that development.

HEAT OUTLOOK:

As far as temperatures are concerned, we are still looking at extreme heat with triple-digit highs for lower valleys through at least Monday. Beyond Monday, there is some uncertainty with regards to temperatures due to the incoming moisture and the uptick in cloud coverage. Current guidance has the triple-digit highs sticking around through much of the week ahead, but expect refinements to the forecast as we hone in on the details of this new pattern. Extreme Heat Warnings and Heat Advisories remain in effect through Monday evening.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1203 PM MDT Sun Jul 12 2026

Easterly flow aloft may disrupt the typical diurnal winds at some of the sites. Isolated showers and storms will be possible this afternoon across the Four Corners and San Juans and to a lesser extent the central mountains. Gusty outflow winds will be the main concern. For now, only included KTEX with -TSRA. Outside of convection, a few gusty winds can't be ruled out either. Smoke may impact some sites overnight.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Extreme Heat Warning until midnight MDT Monday night for COZ001-002-006-007. Heat Advisory until midnight MDT tonight for COZ011-020-021. UT...Extreme Heat Warning until midnight MDT Monday night for UTZ024-027. Extreme Heat Warning until midnight MDT tonight for UTZ022-029.