textproduct: Grand Junction

KEY MESSAGES

- Record heat and predominately dry conditions persist through much of the coming week.

- Critical fire weather conditions will occur over southeast Utah and southwest Colorado valleys Monday afternoon due to wind gusts 25-35 mph and low RH, where Red Flag Warning is in effect. Localized critical fire weather conditions elsewhere.

- Isolated afternoon showers and thunderstorms over the southern mountains moving off into the valleys possible through early this week.

DISCUSSION

Issued at 1100 PM MDT Sun Aug 2 2026

HOT AND DRY CONDITIONS THIS WEEK:

High pressure will remain centered over the Desert Southwest this week with a hot and dry air mass remaining in place. Triple digit heat will be common for the lower valleys of eastern Utah and west-central Colorado where Extreme Heat Warnings and Heat Advisories are in effect through Tuesday evening but could be extended day by day as heat remains with little change in the pattern. Another thing that will come from these hot and dry conditions is the return of critical fire weather conditions. While most areas look to remain localized, the Four Corners valleys will see some increased gusty winds on Monday afternoon as a shortwave trough passes to the north and allows for some deeper mixing. Wind gusts are projected to be in the 25 to 35 mph range for southeast Utah and southwest Colorado valleys with RH in the single digits to low teens, so went ahead and issued a Red Flag Warning for Monday for UTZ491 and COZ207 from noon to 8 pm MDT. A few more passing shortwaves look to move across the Northern Rockies dropping over the Front Range. While we remain hot and dry, there is a non-zero chance of isolated virga showers and/or thunderstorms mainly along the eastern San Juans and up the Divide, but most activity should remain east. Wetting rain chances appear non-existent in this hot and dry air mass.

LOOKING AHEAD:

Looking further out, toward the end of the workweek and the coming weekend, ensemble and deterministic guidance seem inclined to bring a trough into the West Coast. This would finally displace the high to the east, potentially allowing moisture to be drawn up into the Four Corners once more. Models were indicating this moisture and storm increase potentially happening late this week but have really backed off and pushed this back to late this coming weekend into next week. This will be something to watch over the coming days as forecast confidence increases but confidence is low at this time.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 526 AM MDT Mon Aug 3 2026

VFR conditions will continue across the region over the next 24 hours. Upper level winds will increase as a wave works across the Intermountain West. Surface winds on the West Slope will gust 25 to 30 mph Monday afternoon at most of the terminals. Thin mid and upper level clouds will work through as well. Some visibility impacts are likely too, as wildfire smoke intrudes from the west. Left smoke out of TAFs for now, terminals along and north of I-70 could see visibility down to around 5sm. A non zero chance for thunderstorms on the eastern San Juans remains in the forecast. This could produce some gusty outflow winds, but little in the way of breakpoint ceilings and visibility. Clear skies and light winds will return Monday evening.

FIRE WEATHER

Issued at 1100 PM MDT Sun Aug 2 2026

Hot and dry conditions will persist through much of the coming week. Critical fire weather conditions are expected for valleys of southeast UT and southwest CO Monday with gusts of 25 to 35 mph and low RH in the single digits to low teens. Therefore, decided to issue a Red Flag Warning for UTZ491 and COZ207 Monday from noon to 8 pm MDT. Localized conditions possible elsewhere. Non zero chances for isolated thunderstorms are forecast for the San Juans over the next couple days. Wetting rains are not expected.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Heat Advisory until 9 PM MDT Tuesday for COZ006. Red Flag Warning from noon today to 8 PM MDT this evening for COZ207. UT...Heat Advisory until 9 PM MDT Tuesday for UTZ022. Red Flag Warning from noon today to 8 PM MDT this evening for UTZ491. Extreme Heat Warning until 9 PM MDT this evening for UTZ027- 029. Heat Advisory from 9 PM this evening to 9 PM MDT Tuesday for UTZ027-029.