textproduct: Grand Junction

KEY MESSAGES

- Isolated showers and storms are possible (20%) this afternoon, mainly favoring the San Juans and Eastern Uintas. Virga and erratic outflow winds will be more prevalent than any wetting rain.

- Widespread critical fire weather conditions will be around Saturday, Red Flag Warnings are in effect.

- By Sunday, critical fire weather conditions will become more localized, with a return of hot and dry conditions into early next week

DISCUSSION

Issued at 1111 AM MDT Fri Jun 19 2026

An upper level ridge will begin to break down today, as troughing begins to build to our west. Some moisture may be allowed to skirt under the ridge this afternoon. This, in combination with orographic lifting could produce isolated showers and thunderstorms for the higher terrain, mainly favoring the San Juans and Eastern Uintas. Although, the dry airmass that is currently over the region would limit any accumulations, leaving us with mostly virga and erratic outflow winds. Dry lightning will also be a threat. Daytime highs will continue to be 10+ degrees above normal today.

WEEKEND OUTLOOK:

The trough appears to pass to our north this weekend, bringing a small push of moisture to the northern mountains Saturday and Sunday. Although, little in the way of wetting rain as the dry airmass sticks around. Dry lightning will be a threat this weekend as well. All other locations will remain fairly dry. With the trough passage comes a brief break from triple digit heat, with daytime highs dropping to near or around 5 degrees above normal. Unfortunately, high pressure builds back in over the Southwest early next week, bringing a return to triple digit heat for the desert valleys and highs generally 10+ degrees above normal.

By Saturday, our area will be sandwiched between a weakening ridge and a building trough. This upper level set-up favors gusty winds for our area. Flow will shift to southwesterly during this time period, with gusts between 30-40 mph across much of the region, locally higher gusts are possible. As previously mentioned, we hold onto this dry airmass for the foreseeable future, giving way to relative humidities in the low teens to single digits for all but the highest elevations. Red Flag Warnings will be in effect Saturday for most of eastern Utah and western Colorado. See the fire weather section for more information on that. Once the trough propagates overhead, minimum humidity values tick upward, mainly north of the I- 70 corridor. Winds will also weaken, with localized pockets of 20-30 mph gusts, confined mainly to the Divide.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1111 AM MDT Fri Jun 19 2026

VFR conditions are expected to prevail through the TAF period. Winds will gust up to 25 kts this afternoon, mainly at terminals near the Divide. Mostly clear skies for most of the day until some mid level cloud development later this afternoon for some terminals.

FIRE WEATHER

Issued at 1111 AM MDT Fri Jun 19 2026

The upper level ridge will begin to break down over the next day or so as a shortwave disturbance crosses the Great Basin. Pockets of critical fire weather conditions will be around today, but the main event appears to be Saturday, with widespread fire weather conditions expected. Non zero chances for terrain based, mostly dry thunderstorms emerge this afternoon as well, elevating the chances for new fire starts. Red Flag Warnings (12PM-10PM) are in effect Saturday for all western Colorado and eastern Utah fire zones, with the exception of UT Zone 485. Gusts will likely fall within the 30-40 mph range during this time, with locally higher gusts possible. Beyond Saturday, critical fire weather conditions appear to be more localized as triple digit heat returns and minimum relative humidities hang within the 10-15% range. Some showers/thunderstorms could also develop along the northern mountains Sunday, giving way to the possibility of dry lightning.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning from noon to 10 PM MDT Saturday for COZ200>203-205-207-290>295. UT...Red Flag Warning from noon to 10 PM MDT Saturday for UTZ486- 487-490-491.