textproduct: Grand Junction

KEY MESSAGES

- Localized critical fire weather conditions continue Friday, then become widespread under strong winds Saturday.

- The threat of dry thunderstorms emerges Friday and into the weekend, increasing the odds for new fire starts on the terrain.

- Fire weather conditions become more localized Sunday, but temperatures will ramp up next week. Critical fire weather is expected to develop under this hot and dry regime.

DISCUSSION

Issued at 222 PM MDT Thu Jun 18 2026

High pressure will begin to erode Friday, due to a weak shortwave moving across the Great Basin. Despite the hot and dry conditions in place, an isolated thunderstorm on the terrain is not out of the question. This will be the near-term weather threat of concern as the weekend approaches. Surface winds beneath the trough pick up Saturday afternoon, with winds gusting 30 to 40 mph, including some stronger gusts mixed in. This will introduce widespread critical fire weather to eastern UT and western CO. The additional threat of dry lightning could enhance the potential for new fire starts in this regime. The scarcity of surface moisture will nearly guarantee a lack of wetting rains too. This broad trough is slow to exit Sunday and will likely pose some additional threat for a terrain based shower and/or thunderstorm. Cooler temperatures(only 5 degrees over average) will continue this weekend. However, high pressure builds back in and returns triple digit highs to the deserts Monday and beyond.

This hot and dry pattern will likely include localized patches of critical fire weather next week. Daytime mixing could produce winds high enough for more widespread fire weather, but certainty in this regime will be day to day. Of concern most days next week, will be the evolution of the broad high pressure over the southern CONUS. Models are hinting at pockets of moisture slipping beneath the high and infiltrating the region. This will certainly add an additional shower and storm risk to the antecedent critical fire weather conditions. Wetting rains seem unlikely in this hot, dry pattern too.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 522 PM MDT Thu Jun 18 2026

VFR conditions will continue over the next 24 hours under mainly clear skies. A few afternoon breezes with gusts in the 25 to 30 mph range will be possible along with isolated mountain showers.

FIRE WEATHER

Issued at 222 PM MDT Thu Jun 18 2026

High pressure will slowly erode over the next 36 hours as a shortwave disturbance crosses the Great Basin. Critical fire weather conditions will remain localized under lighter winds and hot, dry conditions this afternoon and Friday. Non zero chances for terrain based thunderstorms emerge Friday afternoon, elevating the chances for new fire starts under the antecedent hot, dry regime. This chance increases Saturday afternoon, given the more dynamic environment that develops under the shortwave. Fire Weather Watches are in place for the West Slope and eastern UT on Saturday. The critical fire weather threat will continue Sunday, but looks much more localized in nature. The threat for additional shower/thunderstorm development continues Sunday. High pressure returns next week as high pressure builds back in. Triple digit temperatures likely return to our low desert locales as well, with low relative humidity this will likely include critical fire weather conditions continuing.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Fire Weather Watch from Saturday afternoon through Saturday evening for COZ200>203-205-207-290>295. UT...Fire Weather Watch from Saturday afternoon through Saturday evening for UTZ486-487-490-491.