textproduct: Grand Junction

KEY MESSAGES

- Precipitation totals of 1 to nearly 2 inches is expected through Thursday afternoon.

- Snow, mainly above 10K ft, is possible over most ranges, but most favoring the eastern Uintas, San Juans, and central mountains through midweek.

- Much cooler temperatures can be expected over the next several days with below freezing overnight temperatures possible by Thursday morning in some higher valley locations.

DISCUSSION

Issued at 1054 PM MDT Mon Oct 12 2026

Ridging continues to dominate the eastern half of the country, while troughing digs into the Great Basin this evening. Southwesterly flow ahead of this trough continues to stream anomalously rich moisture into eastern Utah and western Colorado, although drier air is mixing aloft. Even with the drying aloft, PWATs remain well above normal and are expected to continue to do so through Thursday. Broad dynamic lift, courtesy of a jet streak aloft and the close low at the base of the approaching trough, will keep widespread precipitation in the forecast, with chances for a stray thunderstorm or two. Minor accumulations of snow will be possible at elevations above 10k through the period.

As the low swings across the Four Corners Wednesday morning, colder air will work in aloft. This will increase instability and start to lower snow levels a bit, resulting in the best chances for accumulating snowfall. Models remain zealous as far as snow totals are concerned, likely not accounting for the very warm antecedent conditions and still warm ground temperatures. A couple of inches at elevations above 9500 feet will be possible, and could lead to some slushy, messy commutes over mountain passes on Wednesday morning. Have continued to hold off on issuing any winter highlights, but will reevaluate the need for them with the next forecast package.

The low finally tracks into the Plains Thursday, though wrap-around moisture will keep showers going through Thursday afternoon for northern portions of the area. As skies clear, conditions are set for good radiational cooling. Northern valleys will likely see lows drop below freezing, so stay tuned for the potential for freeze products.

Abundant cloud cover and showers, as well as the much cooler airmass ushered in by the approaching trough, will keep temperatures well below normal through Thursday. Highs on Wednesday are currently forecast to run a good 10-15 degrees below mid-October normals. Things will certainly feel fall-like across the Western Slope. Temperatures start to rebound by the weekend as high pressure tries to build in from the west, reaching near-normal by Sunday.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1134 PM MDT Mon Oct 12 2026

Showers with embedded thunderstorms will continue to drift northward through this forecast period. VFR/ILS will prevail at most area through this time but there will be temporary IFR/MVFR conditions under heavier showers with low ceilings also a threat. Strong Southwest winds aloft is pulling this moisture across the area and will lead to pockets of LLWS. These winds could also be pulled down to the surface with the showers and bring gusts up to 35 mph at the TAF sites. Showers and the threat of lower flight criteria will continue through mid-week.

GJT WATCHES/WARNINGS/ADVISORIES

CO...None. UT...None.