textproduct: Grand Junction

KEY MESSAGES

- Showers and thunderstorms spread across the region tonight. Meager accumulations could lead to new fire starts.

- Shower activity could suppress smoke tonight and tomorrow. However, dry and windy conditions are expected to produce additional smoke from nearby wildfires Friday and beyond.

- Hot, dry, and windy conditions return on Friday. Red Flag Warnings are in place for eastern UT and western CO.

- Critical fire weather conditions amplify Saturday due to strong surface winds across the region.

DISCUSSION

Issued at 155 PM MDT Wed Jun 24 2026

Surface moisture continues to increase across the Four Corners and northward to the I-70 corridor. Showers and thunderstorms have developed on the terrain with some trace amounts of rain reaching the surface. Fire starts remain a threat due to lightning and dry fuels. Moisture continues to spread northward tonight and Thursday. This will lead to more widespread showers and thunderstorms. The higher relative humidities will suppress critical fire weather on Thursday. Low pressure digs into the PACNW Friday. This will quickly collapse the ridge overhead and drive up surface winds in the southwesterly flow ahead of the low. Relative humidities bottom back out Friday afternoon for eastern UT and western CO. Red Flag Warnings have been issued for both sides of the state line Friday.

Pressure gradients tighten considerably Friday afternoon and overnight. The gusty winds and poor relative humidity recovery will keep Red Flag conditions in place for eastern UT Friday night and beyond. Winds continue to strengthen on Saturday across the region with widespread gusts of 40-50 mph, including a few stronger gusts. Fire Weather Watches are in place for the entirety of Western Colorado. Rather than eject out of the Rockies, this low will begin to slowly fill late Sunday. This will keep stronger winds aloft parked overhead. It looks like critical fire weather conditions will continue in some capacity Sunday and beyond behind this system. Temperatures will adjust down early next week with some cooler air. This remains a low confidence forecast, considering the impacts of wildfire smoke on afternoon highs and mixing. Surface wind speeds could be overestimated should weekend fire activity ramp up the smoke again. Likewise, temperatures could be overforecasted should skies remain smoke filled.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1149 AM MDT Wed Jun 24 2026

Smoke from Utah wildfires continues to impact many sites by reducing visibility, and will continue to do so during much of the afternoon. Moisture will move in within the next few hours, bringing increased chances for precipitation through tomorrow night. With the initial onset of rainfall today gusty outflow winds and lightning are the primary concerns, but this evening more rain is expected to reach the ground, possibly causing periods of MVFR conditions. This moisture is also expected to lower ceilings below ILS breakpoints at many sites for periods of time. Wind gusts 15 to 25 kts are expected this afternoon, but areas with dense wildfire smoke could have reduced wind gusts.

FIRE WEATHER

Issued at 155 PM MDT Wed Jun 24 2026

Critical fire weather conditions are getting a hand from a plume of moisture lifting across the Four Corners. Antecedent dry conditions pose a risk for new lightning fire starts. This moisture will spread across the region tonight and Thursday, suppressing critical fire weather conditions. Some wetting rains are possible, but lightning starts remain a concern due to the hot, dry, windy conditions returning Friday ahead of a low diving into the PACNW. This system quickly ramps up surface winds Friday afternoon. Low relative humidities return to eastern UT and western CO, leading to Red Flag Warnings along the state line Friday. Relative humidities recover very little Friday night and thus Red Flags will remain in place through Saturday night for eastern UT. The state line zones on the CO side will see their Red Flag Warnings expire Friday night due to the better recovery of relative humidities. However, Fire Watches have been issued for Saturday across the entire West Slope of Colorado. These will likely be upgraded to Red Flag Warnings in subsequent forecast packages. Wind speeds on Saturday remain concerning due to gusts in excess of 50 mph. Relative humidities near 10 percent in the gusty environment are expected to lead to extreme fire behavior. These conditions following an outbreak of lightning will remain a forecast concern through the weekend, as winds are expected to remain elevated into Sunday, while the system exits the region.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning from noon to 9 PM MDT Friday for COZ200-202- 203-207-290. Fire Weather Watch from Saturday morning through Saturday evening for COZ200>203-205-207-290>295. UT...Red Flag Warning from noon Friday to midnight MDT Saturday night for UTZ486-487-490-491.