textproduct: Grand Junction

KEY MESSAGES

- Travel on mountain passes the next 24 hours could be difficult with blowing/drifting snow and poor visibilities.

- Winter Weather Advisories remain in place for the northern mountains where 6 to 12 inches of snow is expected. The Flat Tops and Central Mountains above 10,000 feet also have advisories for 4 to 8 inches. - Well above normal temperatures continue with record highs possible to begin the week.

- Unsettled conditions return ahead of Christmas.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 209 PM MST Fri Dec 19 2025

A broad band of westerly winds skirting a notable polar jet is working across the Mountain West this afternoon. Widespread gravity waves can be seen on satellite imagery. This morning's sounding here at the station shows capping overhead, keeping some of those winds from mixing down yet. That should change through the afternoon. In fact, Meeker and Craig have already seen some gusty winds. The broken cloud cover has been problematic for mixing thus far. Moisture transport near the frontal boundary along the jet is respectable through the column. Temperatures are still a problem for snow at this hour of the day. The frontal boundary drifts south after sunset and given the expected shot of moisture, we should see some orographic showers pick up on the northern mountains late this evening before midnight. Winter Weather Advisories for the mountains are still in effect after midnight. Snow should pick up w a few stronger banded showers along the front. Late night travelers on mountain passes from I-70 to the north are advised to be prepared for poor visibility due to blowing/drifting snow in the gusty winds.

Snow continues across the mountains on Saturday as the east-west oriented frontal boundary parks overhead. The jet max subsides enough to slow down surface winds, but breezy conditions will still be enough to blow snow around on the high country. Temperatures will cool across the northern half of the CWA Saturday, while the front washes out southward and mild, warm conditions continue around the Four Corners. Snow rates fall off Saturday evening, as a push of warmer, drier air nudges the front back north and we see the first hints at the pending warmup leading into the Winter Solstice. Morning lows will trend warmer on Sunday morning thanks to lingering cloud cover across the region.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 209 PM MST Fri Dec 19 2025

Sunday and Monday are shaping up to be essentially the same with mild moisture reaching our CWA, prompting weak rain and snow showers primarily over the northern Colorado mountains. Only a few inches of snow accumulation is expected generally above 8000 ft due to the persistent warmer-than-normal temperatures.

The stubborn zonal upper-level flow finally gives way beginning Tuesday as a deep trough develops off the west coast. Flow shifts southwesterly across the western CONUS as a result, pulling with it a broad plume of anomalously high moisture overhead. Ensembles are still varying a fair amount regarding how strong this surge of moisture will be with the ECMWF running wetter than the GEFS, but with both signaling PWAT's will easily surpass the 90th percentile of PWAT climatology, and paired with more favorable upper-level support, confidence is high in active weather during the holidays. Now for the bad news. Though the trough should drop temperatures marginally, high temperatures are still on track to be 10-20 degrees above normal through the end of the week, and lows could be even more anomalous, upwards of 25 degrees above normal. This is keeping snow levels high, essentially removing any possibility for lower valleys to receive snowfall as most, if not all precipitation should be rain here. Higher elevation valleys will be iffy too, perhaps favoring mixed precipitation depending on the exact elevation of snow levels. Even where snow will dominate in our mountain zones, the warmer temperatures would greatly inhibit snow ratios and accumulation will be relatively wet. Overall, there's hope that this system will help moisten up our struggling snow pack, but winter recreation is looking to stay less-than-optimal with the wet snow, and lower slopes may not even see that. Regardless, travel impacts are becoming more and more likely during this period, and so it is important to stay aware of the latest forecast guidance and begin making preparations for safe travel should you plan to find yourself on the roads for the holidays.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 403 PM MST Fri Dec 19 2025

Increasing cloud cover brings a chance for precipitation over high elevation TAF's beginning tonight. Cigs may near or drop below ILS breakpoints at KASE, KEGE, and KHDN, during this period, and visibility could be reduced to MVFR conditions as snow and rain showers occur. Mechanical turbulence and mountain obscuration will be additional concerns.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Winter Weather Advisory from midnight tonight to midnight MST Saturday night for COZ004-010-013. UT...None.