textproduct: Grand Junction

KEY MESSAGES

- Critical fire weather conditions will remain mostly south of the Colorado River today.

- Above normal temperatures make a return for the holiday weekend and beyond.

- Isolated showers and thunderstorms could return as early as Sunday, with coverage increasing Monday.

- Chances for wetting rain remain low, instead dry lightning poses a threat to new fire starts early next week.

DISCUSSION

Issued at 1059 AM MDT Fri Jul 3 2026

TODAY THROUGH THE HOLIDAY WEEKEND:

The upper level trough we have been situated under for the past week finally begins to break down this weekend ahead of a building ridge. Southwest flow aloft continues to dominate today with a marginal upper level jet located south of the Colorado River. This will lead to critical fire weather conditions in the southern portions of western Colorado, with gusts up to 30 mph expected in those areas today. Convergent flow above the Uintas through the weekend looks to tap into some elevated moisture leading to isolated storms mainly over the higher terrain of northeast Utah each afternoon.

The aforementioned ridge of high pressure begins building over the Rockies throughout the weekend leading to a weaker zonal flow pattern aloft. This will cease widespread critical fire weather conditions for the time being, with only localized pockets of afternoon gusts. Even though the gusts will be lower magnitude, conditions continue to be very dry, with minimum relative humidities hovering around the single digits for most of the lower elevations. With that being said, continue to follow local fire restrictions for the holiday weekend. Daytime highs are forecast to begin rising above normal beginning this weekend, with near triple digit heat expected for some of the desert valleys by Sunday. It is important to note that depending on how long this smoke remains in the area, forecasted daytime highs may be a tad overestimated in some places as smoke may reduce the strength of daytime heating. Regardless, it will be hot this weekend into the work week ahead.

WHEN COULD WE SEE MOISTURE?

Anticyclonic flow around the high pressure centered over the Southern Rockies combined with cyclonic flow ahead of a trough arriving to the southwest produces a favorable flow for pulling in subtropical moisture. Upon analysis of different global ensembles, it appears the GFS wants to bring in moisture Sunday into Monday whereas the Euro brings it in as early as Monday afternoon. Either way, the probability of widespread wetting rainfall with this push of moisture is low. The bigger concern will be dry lightning posing a threat to new wildfire starts in addition to possible erratic outflow winds reaching existing wildfires. Continue to monitor the forecast as changes may be made in regards to timing once more HiRes guidance is made available to us. Moisture lingers through mid week before a northern stream suppresses the ridge to the south and westerly flow aloft brings dry air right back in.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1151 AM MDT Fri Jul 3 2026

Winds will turn west-southwest this afternoon with gusts 15-25 kts. Isolated storms will occur over the eastern Uinta mountains and northern Park Range but are not expected to impact TAF sites. Wildfire smoke will continue to reduce visibility at some locations throughout the next 24 hours. The most likely terminals impacted are KMTJ and KGUC where visibility may reduce to less than 5SM with MVFR conditions. Otherwise, smoke and haze will remain present at most other TAF sites but visibility should remain above 6SM. Winds become light and terrain driven overnight.

FIRE WEATHER

Issued at 1059 AM MDT Fri Jul 3 2026

Critical fire weather conditions remain for much of southwest into west central Colorado today as favorable mixing conditions will take place. Gusts upwards of 30 mph are expected, with higher gusts favoring the terrain. Red Flag Warnings remain in effect for those areas, set to expire at 8 PM tonight. A building upper level ridge this weekend will reduce the threat of widespread critical fire weather conditions. Although, localized pockets of gusty winds could present themselves each afternoon this weekend, mainly confined to the Four Corners area. Despite the winds weakening, persistent hot and dry conditions are expected to continue. Moisture begins working under the high as early as Sunday afternoon/evening. This will lead to isolated to scattered thunderstorm development through early next week. Much of the thunderstorm focus will be on the higher terrain but can not rule out some scattering down towards the adjacent valleys. Fire starts from dry lightning and erratic outflow winds near existing wildfires pose more of a threat than any wetting rainfall. Some relief away from single digit afternoon humidities will arrive with the moisture, which would hopefully aid in reducing wildfire intensity.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning until 8 PM MDT this evening for COZ207- 290>294. UT...None.