5:45 AM MDT, Tuesday, October 12, 2021
Significant snow is likely in the high elevations over the next 24-36 hours. Some areas are likely to get over 12″, but mainly in unpopulated areas above treeline. Watch out for winter travel at the high passes. Some snow will likely occur east of the continental divide, but mainly west of Peak to Peak highway and within a few miles of Eisenhower Tunnel.
For the eastern foothills and plains there may be a brief period with showery rain or graupel today, but little or no overall accumulation (except up toward Cheyenne where light amounts are more likely). A major snowstorm is expected to take shape later today and tonight a short distance north of Cheyenne in east-central and northeastern Wyoming.
As the storm pulls away from the Front Range region this evening, we are likely to see strong west and northwest winds across the eastern foothills and plains this evening through Wednesday morning. With trees still leafed out, there could be some scattered tree and power line damage.
A weaker storm on Thursday should bring some light snow to the mountains and maybe a little rain changing to snow for the eastern foothills and plains. Although the chance for snow in the urban corridor is better with that one, the chance for anything measurable is less than 50-50. However, the chance for widespread freezes by Friday morning is quite good.
6:30 AM MDT, Monday, October 11, 2021
A strong storm system is expected to move across Colorado and into western Nebraska on Tuesday and Tuesday night. It should bring the first significant snow to the mountains (especially west-facing slopes) where 6-12″ is likely. Lesser amounts are expected in western valleys.
The track of the storm won’t result in easterly upslope for the eastern foothills and plains, so much less precipitation is expected there. Some snow may spill over from the west a result in some light accumulation, mainly west of Peak to Peak highway. We may have some brief squally showers (mainly rain) in the urban corridor, but precipitation totals are likely to be scattered and generally light. There is only a very small chance for widespread measurable snow. There is a better chance for some measurable snow in Cheyenne, but the more significant snow and wind is likely to be north of there.
We get another shot for snow on Thursday and Thursday night. The next storm is weaker and will likely bring some light snow amounts to the mountains. The Thursday afternoon/evening storm will bring a better chance for widespread light precipitation (rain changing to snow) for the eastern foothills and plains.
Temperatures through the period (except Tuesday morning) may result in localized frost. By Friday and Saturday mornings, widespread freezes are increasingly likely.
6:30 AM MDT, Friday, October 8, 2021
Two cold fronts and accompanying storm systems are forecast to move through Colorado in the next 4-5 days, one tonight, and a stronger one on Tuesday.
Friday night and Saturday
A storm system is likely to bring some intermittent rain (snow above treeline) to mountain areas tonight and Saturday. For the Front Range foothills and plains, a brief shower is possible, but it is likely to remain mostly (or completely dry) in most areas. There may be some gusty west-northwest winds by Saturday morning. Although it will be a bit cooler this weekend, we should still have relatively mild autumn temperatures.
Tuesday and Tuesday night
A stronger storm system and accompanying cold front is forecast to move through Colorado and Wyoming on Tuesday. That one has a greater potential to bring significant snow to the mountains and high valleys. For the eastern foothills and plains, the chance for significant rain changing to snow is more questionable. Right now the orientation and track of the storm would result in winds changing from mostly south to mostly north, with very little easterly “upslope” flow. That evolution could change, but right now it looks like the best chance for moderate or heavy snow on the east slope will be north of Cheyenne. Updates to come.
You might want to start planning for widespread freezing temperatures on Wednesday and/or Thursday morning.