textproduct: Grand Junction

KEY MESSAGES

- Widespread critical fire weather conditions today ease to localized areas as we head into the end of the week.

- Upper 90s to triple digit heat is expected for the desert valleys through late week with a slight cool down expected through the weekend. Temperatures 10 to 15 degrees above normal return next week.

- Stronger winds and continued low humidity brings a return of widespread critical fire weather conditions on Saturday.

DISCUSSION

Issued at 126 PM MDT Wed Jun 17 2026

The 17/12Z H500 hand analysis map is showing an anomalous blocking low sitting over the Hudson Bay region which is largely responsible for driving the NOAM weather pattern attm. This includes the tight NW flow gradient across the PacNW to the Central Rockies...which is bringing the stronger gusts today. This stronger flow is also holding back a ridge over the Intermountain West under which a batch of moisture is trapped. This pattern remains fairly static through the next 24-36 hours though the strongest wind gradient aloft will shift slightly North and relax a bit over our CWA. This will reduce critical fire weather concerns to more a localized coverage before ramping back up for the weekend. So less windy but no less dry and hot to end out the week with pockets of critical fire weather. The Hudson Bay low won't budge for the weekend but energy in the E.Pacific will be strong enough to progress the pattern through the mid and lower latitudes of the CONUS. This will push the upstream ridge and moisture source across eastern Great Basin and Rockies by Friday afternoon and introduce very remote chances of a mountain thunderstorm through the evening. At this point wind and lightning will be more of a threat than measurable precipitation due to emaciated boundary layer moisture thanks to the ongoing drought. Another windy/critical fire weather pattern sets up for Saturday as a wave digs through the northern Great Basin and pushes a flattened ridge onto the Plains. The core of stronger winds at the base of this wave is overhead and with deep mixing...another breezy/windy...dry and hot day is expected with widespread critical fire weather a probable outcome. Winds relax as we head into Sunday and early next week with temperatures falling back a few degrees...however critical fire weather remains a least localized. Precipitation chances remain meager even with forcing from this wave and a trailing wave moving through on Sunday with interact with a meandering surface boundary. Nothing to really hang a hat on yet but likely at least some isolated thunderstorm chances. The upslope regime on the East side of the divide will have the better chances as usual.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1132 AM MDT Wed Jun 17 2026

VFR conditions under mainly clear skies will continue over the next 24 hours. The main aviation planning concern will be wind gust of 30 to 40 mph this afternoon through sunset. Winds should then drop off to normal diurnal speeds and directions through tomorrow morning.

FIRE WEATHER

Issued at 126 PM MDT Wed Jun 17 2026

Widespread Red Flag conditions are in place this afternoon with gusts of 25 to 40 mph and single digit humidity. Critical fire weather conditions become more localized to end out the week as the core of stronger winds aloft move out of the area. Hot and dry conditions will remain however. Stonger winds return Saturday as an approaching wave breaks down temporary ridge over the Rockies. This is likely to bring a return to widespread critical fire weather conditions. This wave will bring very minimal chances of thunderstorms to the forecast...however gusty winds and lightning will be more of a concern than wetting rainfall. Hot and dry conditions are likely to keep at least localized fire weather concerns in place each day.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning until 9 PM MDT this evening for COZ200>203- 205-207-290>295. UT...Red Flag Warning until 9 PM MDT this evening for UTZ486-487- 490-491.