textproduct: Grand Junction

KEY MESSAGES

- Critical fire weather conditions are expected to continue through Friday.

- The holiday weekend will see lighter winds and near triple digit heat in the desert valleys.

- Hot and dry conditions will continue into next week, with little chances of wetting rain.

DISCUSSION

Issued at 1237 PM MDT Wed Jul 1 2026

THE WORK WEEK:

The current synoptic level flow is characterized by troughing over the west and ridging to the east. This keeps much of eastern Utah and western Colorado sandwiched between the two features with mainly southwesterly flow. Afternoon gusts are expected daily, with values of 20-30 mph. A few passing shortwaves throughout the week will interrupt the parent longwave flow which will bring the possibility for higher afternoon gusts (25-35 mph). Additionally, these shortwaves also look to clip some of the northern parts of our CWA, giving way to mostly virga showers or dry thunderstorms over northeastern Utah each afternoon. This poses a threat to new fire starts as a result of dry lightning. Dry conditions appear to stick around for the foreseeable future for the entirety of the area. Daytime minimum humidities will be hovering around the single digits and low teens for much of the area through the week. Fire weather highlights are in effect, see the Fire Weather section for more information on that. Thanks to the slightly cooler airmass associated with this trough, daytime highs through the end of the work week will be near or below normal.

THE HOLIDAY WEEKEND:

High pressure begins to build back in by the weekend, putting the area under zonal flow aloft and a return of above normal temperatures. Near triple digit heat is expected for the desert valleys through the weekend. Winds finally begin to relax this weekend ahead of this building high pressure. This will lead to a hot, yet pleasant holiday weekend with minimal cloud coverage. Current guidance suggests a chance of tapping into subtropical moisture early next week, but at this point it doesn't appear to be significant. This is also dependent on where the high pressure establishes itself. If it ends up centering over the Desert Southwest, moisture would be favored to the east and west of us. With the continued dry surface conditions, erratic virga outflows and dry thunderstorms are more likely than any substantial wetting rain.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1134 AM MDT Wed Jul 1 2026

A smoke layer...at times rooted closer to the ground...will be the biggest impact to aviation over the next 24 hours. Expect fires to become more active through the afternoon with a layer of smoke impacting downstream TAF sites with a few areas of dropping to below P6SM. KMTJ may once again be the most impacted by downvalley winds pulling in smoke overnight and dropping to MVFR levels. Will add this to forecast later as confidence increases. Otherwise afternoon breezes 25 to 30 mph can be expected at times with winds becoming light by sunset.

FIRE WEATHER

Issued at 1237 PM MDT Wed Jul 1 2026

Red Flag conditions are expected through Friday before the trough begins to finally break down this weekend. Red Flag Warnings remain in effect until 8 PM for much of southeast Utah and southwest Colorado today. For the rest of the week, fire weather conditions appear to be marginal compared to previous days. Single digit relative humidities and gusts around 25-35 mph are expected each afternoon through Friday. Hence, upgraded the Fire Weather Watch Thursday to a Red Flag Warning for some of the same zones. Chose to leave out COZ295 as confidence was not high enough in the wind speeds for that area to meet criteria. A series of weaker upper level disturbances in the flow could give way to dry thunderstorms across northeast UT and northwest CO this week. While this remains an isolated chance, the persistent critical fire weather pattern will pose a threat to lightning starts. Wetting rain remains highly unlikely for this week and the weekend as we hold onto to the dry conditions for the foreseeable future.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning until 8 PM MDT this evening for COZ203-205- 207-290>295. Red Flag Warning from noon to 8 PM MDT Thursday for COZ205-207- 290>294. UT...Red Flag Warning until 8 PM MDT this evening for UTZ491. Red Flag Warning from noon to 8 PM MDT Thursday for UTZ491.