textproduct: Grand Junction

KEY MESSAGES

- 1 to nearly 2 inches of precipitation is expected through Thursday afternoon. Snow, mainly above 10K ft, is possible over the eastern Uintas, San Juans, and central mountains through midweek.

- Wind gusts of 25 to 35 mph will be possible over higher terrain today and the Four Corners region.

- 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 1203 PM MDT Mon Oct 12 2026

ANOMALOUS MOISTURE AND INCREASING PRECIP CHANCES THROUGH MIDWEEK

The remnants of TS Rachel continues to influence the Western Slope and eastern Utah forecast area as an unusually moist airmass remains in place ahead of an upper-level trough digging into the Intermountain West. A blocking ridge downstream is slowing the progression of this system and will allow the trough to linger across the region through early Tuesday. Broad southwest flow aloft and at the surface will keep scattered showers and isolated thunderstorms in the forecast. Cloud cover will inhibit convection today but a quick break in this cloud cover should allow some storms to get going. Outside of convection, we are already seeing a line of heavier showers moving from south to north just N of the I-70 corridor bringing a more soaking type rain. Latest HREF guidance is showing low and mid clouds remaining predominant through tomorrow afternoon and beyond. Having said all that, the chance still exists for convection so keep an eye to the skies if recreating over the next few days. Some gusty winds of 25 to 30 mph are also expected though not as strong as yesterday.

The upper low is forecast to dig southeastward, reaching the Four Corners by Wednesday morning. As this occurs, a strong jet streak will remain overhead providing wide scale lift and with all the moisture remaining, more widespread precip is expected through the day Tuesday, continuing through Thursday. All higher terrain will see the best chances for this precip with adjacent valleys/foothills also seeing some precip, albeit somewhat lower. As the low moves across the CWA, precip amounts and coverage will increase from the San Juans Wed early afternoon and shift to portions of the central mountains by Wednesday evening. Of course, the track of the low is very important on where the heaviest precip will fall and confidence in this regard remains in the medium category.

With the arrival of colder air, snow levels will drop to 10K feet, if not a little below. This will allow some accumulating snow for the higher terrain, especially above 10K feet. Look for 1 to 2 inches of snow with some locally higher amounts possible, especially for the eastern Uintas. Will NOT be issuing any highlights as impacts are expected to remain above pass level and the snow that does fall at that level should melt. Can re- evaluate as the colder air moves in.

Wraparound moisture from the closed low will finally end Thursday morning as the parent low moves to the Plains. Temperatures will slowly start to increase but will remain at or just below normal. Morning lows Thursday could drop below freezing for some northern valleys. A drier pattern develops Thursday bringing a return to more sunny skies, warming temperatures and dry conditions.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1203 PM MDT Mon Oct 12 2026

Scattered showers and embedded thunderstorms are generally confined to eastern Utah while skies are beginning to clear over Colorado. Another round of showers and thunderstorms are expected to develop this afternoon, begin to move eastward, and become more widespread overnight. Some showers and storms could produce heavy rain and gusty winds. Outside of thunderstorms, gusty winds as high as 25-35 kt will remain in place over the region.

GJT WATCHES/WARNINGS/ADVISORIES

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