textproduct: Grand Junction

KEY MESSAGES

- Critical fire weather conditions are expected to continue through the work week.

- Critical fire weather conditions abate this weekend, as winds lighten and temperatures surge back above normal for the holiday weekend.

- Hot and dry conditions persist with little chance for wetting rains.

DISCUSSION

Issued at 935 PM MDT Tue Jun 30 2026

There is little change in the longwave pattern through the end of the week, as troughing dominates the west and ridging to the east. This keeps eastern Utah and western Colorado under breezy southwesterly flow. Afternoon gusts of 20-30 mph are expected daily. Passing shortwaves will bring periods of higher wind gusts, 25-35 mph, with locally up to 40 mph. Additionally, these waves will have just enough moisture with them to create a few virga showers or dry thunderstorms over northeastern Utah, raising the concern for lightning starts. Surface levels remain extremely dry, with daytime minimum humidity values in the single digits for the lower elevations, and the low teens higher up. As a result, Critical Fire Weather conditions remain with us through at least the end of the week. Red Flag Warnings are in effect from noon to 9PM Wednesday, with Fire Weather Watches in effect from noon to 9PM Thursday.

The slightly cooler airmass associated with the trough will keep our temperatures at or a few degrees below normal through the end of the week. However, by the weekend flow aloft begins to shift zonal as high pressure tries to build into the southwest. Winds will finally relax, and temperatures will jump to around 5 degrees above normal in response. There are hints that some subtropical moisture will work its way northward under the high by early next week, however the overall pattern isn't that favorable for a good tap of deep moisture. With the high directly over the Desert Southwest, moisture is more likely to reach areas to our east and west. And with dry surface conditions still in place, virga showers, gusty winds, and dry thunderstorms are more likely that any substantial wetting rain.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 518 PM MDT Tue Jun 30 2026

Southwest winds around most terminals will gust 20-30 knots, with some localized areas seeing stronger winds gusting up to 40 knots expected in the Four Corners region. Smoke may lead to visibility reductions from time to time. Same conditions are expected tomorrow although slightly lower wind speeds.

FIRE WEATHER

Issued at 935 PM MDT Tue Jun 30 2026

Red Flag conditions are expected through at least Friday before the stagnant trough driving the dry and windy setup finally appears to break down into more zonal flow with weaker winds into the weekend. For most days, fire weather appears marginal to moderate with single- digit relative humidities and gusts around 25-35 mph. A series of weaker upper level disturbances could touch off some dry thunderstorms across northeast UT and northwest CO this week. While this remains a very isolated chance, the persistent critical fire weather pattern will lend a hand to lightning started wildfires this week. Wetting rains remain highly unlikely through the week.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning from noon to 8 PM MDT Wednesday for COZ203- 205-207-290>295. Fire Weather Watch from Thursday afternoon through Thursday evening for COZ205-207-290>295. UT...Red Flag Warning from noon to 8 PM MDT Wednesday for UTZ491. Fire Weather Watch from Thursday afternoon through Thursday evening for UTZ491.