Dillon, CO Weather

Key messages

- Mild and mostly dry through the work week.

- Unsettled weather returns late this weekend and early next week. Mountain snow is likely (>70% chance) above 8500ft during this time. High uncertainty remains for the foothills and plains.

.DISCUSSION /Through Wednesday/: Issued at 1032 PM MDT Wed Oct 28 2026

SW flow aloft will be over the area Thu thru Fri. A weak disturbance will be embedded in the flow on Fri. However, it appears most of the moisture with this feature will stay mainly to the east, with only a slight chc of showers over he far nern plains. Temperatures both days will stay in the 60's over the plains.

By Sat, little change is expected as SW flow aloft remains over the area. There appears to be a weak disturbance embedded in the flow which may bring a chc of showers to portions of the higher terrain. Temperatures will remain in the 60's over nern CO.

Looking ahead to Sun and Sun night, there continues to be a lot of uncertainty as to how an upper level trough over the Pacific NW evolves. The ECMWF has this feature moving southeast with a closed low developing over the Great Basin by Sun night. Meanwhile, the GFS has the system moving more east southeast with a closed low over swrn WY by Sun night. Ahead of this feature, both models do have an influx of subtropical moisture with an increasing chc of showers over the higher terrain late Sun aftn thru Sun night. Over the plains, a sfc lee trough will extend from ern WY into ern CO with southerly low level flow. Most of the plains will be dry thru Sun aftn, but shower activity may gradually increase Sun night.

For early next week, the ECMWF has an upper level low near the 4 corners area by 12z Mon which moves east southeast across nrn New Mexico thru late Mon aftn. Meanwhile, the GFS has the upper level low over swrn WY moving east southeast across central CO into sern CO by late Mon aftn. As a result, these two differing solutions lead to varying amounts of precipitation over the area. The ECMWF solution would keep the heavier precipitation focused over srn CO while the GFS solution would focus further north over nern CO.

Furthermore, the fcst continues complicated for Mon night into Tue as the ECMWF has the upper level low moving southeast into wrn Texas while the GFS has the upper level low over central Kansas. The ECMWF solution would have precipitation ending over most of the area by 12z Tue while the GFS solution would have lingering precipitation thru Tue aftn over portions of the plains. In addition, both models do have a shot of cooler air moving in Mon thru Mon night which could change some of the rain to snow late Mon night into Tues morning at lower elevations. However, ensemble data from both models only show very light accumulations below 6000 ft if the rain does change to snow. To complicate things even further, the Canadian solution keeps the track of the main upper level low well to the north of the area from late Sun night thru Tue morning. As a result, it has very little precipitation across the area due to its northern track. Thus, there remains a tremendous amount of uncertainty as to how things will develop Sun night thru Tue.

.AVIATION /12Z TAFS through 12Z Friday/: Issued at 516 AM MDT Thu Oct 29 2026

VFR conditions will prevail for all terminals through the TAF period. Light SW drainage flow is currently in place at KDEN/KAPA and will persist until slightly after sunrise, before becoming increasingly light and VRB (< 6 kts) after ~15-16Z. Come early afternoon (~19-20Z), east flow looks to become established at the above terminals. It should initially be rather light, but a 2-3 hr window of modestly stronger speeds 10-12 kts could play out, mainly 21-00Z. It's possible KDEN sees a slight nudge towards an ENE wind near or shortly ater 00Z (< 10 kts), but this will quickly swing clockwise back towards typical southerly drainage flow patterns mid-evening, with lighter speeds.

Watches, warnings and advisories

None.