textproduct: Grand Junction

KEY MESSAGES

- Additional snow accumulations are expected in the mountains through tonight, with the greatest accumulations expected in the San Juans. - Brief ridging builds in Thursday bringing pleasant weather with below normal highs.

- Unsettled weather remains in the forecast Friday and into the weekend.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 231 PM MST Wed Dec 3 2025

A thick layer of cloud cover across the CWA can be seen on satellite imagery. This cloud cover, and the ongoing snowfall, is a product of a trough that is propagating through the Four Corners region. Lift from synoptic forcing that is associated with the trough, in combination with lingering atmospheric moisture, will support snowfall through tonight. Most of the additional snow accumulations is expected to occur in the San Juans, but some accumulating snow may still occur in the central and northern mountains of Colorado. An additional 4 to 8 inches is expected in the San Juan Mountains, with locally higher amounts possible.

Tomorrow morning the trough axis will be to our southeast, and anomalously dry air will move into the area. Thus, snowfall from this system will end in the early morning hours due to the loss of forcing and moisture. With dry air in place, quiet weather is expected through the day Tuesday. High temperatures will remain below normal through the short term. Unsettled winter weather looks to return in the long term.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 231 PM MST Wed Dec 3 2025

Models remain in fairly good agreement for a longer period of unsettled weather, especially for the northern mountains starting Friday and persisting through the weekend. An area of high pressure is expected to setup off the West Coast and as this occurs, the jet stream will ride up and over said ridge. The jet will have a northwest to southwest orientation, taking aim at the northern mountains. As impulses of energy move through the mean flow, accumulating snow will begin over the northern mountains, Flat Tops, and also the central mountains. Favorable northwest, orographic flow will keep snow going for the northern mountains as these impulses move off. Ensembles and deterministic models are showing the same solutions so confidence is increasing that the first 'big' snow for the northern mountains is on its way. Monday and Tuesday, the high out west shifts a little east, just enough to cause wind flow to become more westerly, shutting off the orographic lift, leaving a few showers to contend with but little else. Temperatures will run right around normal, if not a little above Saturday onwards.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 941 PM MST Wed Dec 3 2025

Snow will continue to dissipate from north to south along the Divide mountains overnight leaving behind lower ceilings and the potential for fog at terminals that see clearing skies. Confidence for when and where this fog will form is very low, but included the mention of BCFG where fog is historically favored. VFR conditions become widespread after sunrise on Thursday with light winds and mostly clear skies before the next weather system begins to move in north of I-70 late in the TAF period.

GJT WATCHES/WARNINGS/ADVISORIES

CO...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.