textproduct: Grand Junction

KEY MESSAGES

- 4 to 8 inches with locally higher amounts are expected over portions of the Colorado mountains through Thursday morning. Winter Weather Advisories are in place.

- Brief ridging builds in Thursday bringing pleasant weather with below normal highs.

- Persistent snowfall is looking more likely Friday and into the weekend for our northern mountains.

SHORT TERM /THROUGH THURSDAY/

Issued at 320 AM MST Wed Dec 3 2025

As seen on yesterday's Grand Junction sounding evolution, a nose of warmer, moister air slid in atop a cold pool. This feature and persistent westerly upglide has produced light orographic snow through the overnight hours around the region. The snow board here at the station saw 20:1 snow ratios at one point. With this cold, stratiform air mass and a meager moisture pool, rates of accumulation have been pretty stagnant. This should change after daybreak when we can hopefully stir things up. Snowfall picks up across our Central Mountains and southward this morning with a series of vort lobes pivoting through the upper trough. There were some initial concerns with this storm as to whether it could dig far enough south to tap a favorable plume of moisture that could reach into the Four Corners. That seems to be coming to fruition as we've seen QPF ratchet up for the San Juans and their southerly aspects. Good upslope flow nosing into the San Juan Basin around Pagosa Springs today lead me to add an additional Winter Weather Advisory there, where it looks like a solid 5 inches of new snow could fall through Thursday morning.

While snow will taper rapidly this evening for our Central Mountains and the north side of the San Juans, another healthy round of snow is expected into the overnight hours across the southern San Juans. This should be the last gasps of the upper trough exiting the region. Snow should be mostly wrapped up by daybreak Thursday, with scattered flurries lingering into the afternoon. The clearing line of cloud cover reaches the Colorado River corridor this evening and will work south during the overnight hours. Overnight lows behind the clearing skies will dip 5 degrees below climatology and likely cooler in the elevated basins near new snowpack. Mostly sunny skies and cool temperatures will return Thursday. Some afternoon cloud cover will begin to invade northwest Colorado and northeast Utah though, ahead of another push of active weather. Remnant moisture on the San Juans will likely keep some gray skies and isolated flurries down there Thursday, with maybe a stray inch of new accumulation expected.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Issued at 320 AM MST Wed Dec 3 2025

Beginning Friday, continuous high elevation snow looks possible through the weekend, especially for the northern and central mountains. Atmospheric moisture looks to become slightly elevated on Friday from a weak push of moisture, and then even more elevated on Saturday as a stronger moisture push occurs. The increased moisture, orographic lift from northwesterly flow, and a few weak waves of energy may allow for 4 to 8 inches of snow in the northern and central mountains, and possibly higher amounts in the Park Range by the end of the weekend. There seems to be ok agreement on timing of snowfall, including between ensembles, from run to run, and between ensemble members. However, there are still pretty significant differences regarding snow amounts. So, there is definitely still uncertainty with how much snow will accumulate. High temperatures look to warm through the long term, beginning well below normal on Thursday, and becoming near or above normal by early next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 440 AM MST Wed Dec 3 2025

Widespread IFR conditions will prevail this morning and into the afternoon as a winter storm works through the region. Ceilings will improve northwest to southeast this afternoon, with areas north of I-70 clearing out this evening. Mountain terminals will continue to deal with breakpoint conditions through the evening hours and into Thursday morning. Winds remain light through the period.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Winter Weather Advisory until 5 PM MST this afternoon for COZ004-010. Winter Weather Advisory until 2 AM MST Thursday for COZ009-012- 017>019. Winter Weather Advisory until 5 AM MST Thursday for COZ023. UT...None.