9:25 AM, Friday, December 2, 2016
A weak storm system is passing mainly to the south of Colorado today, but it is managing to generate radar returns over the Front Range (moving up from the south). Some of what the radar is sensing is evaporating before reaching the ground. Even with the sub-cloud dryness, it appears that much of the Front Range region will see flurries, and maybe a few more moderate snow showers in some local spots. Accumulation through this evening should range from zero or dusting (many areas) to 1 inch in a few spots.
Expect a dry weekend with cold mornings but probably a bit milder by Sunday with low elevations temperatures approaching 50. Don’t get used to it.
What may be the coldest air mass so far this season is likely to start moving into the Front Range region late Monday and keep temperatures below freezing all day Tuesday and Wednesday. Snow? Two reliable models, the American GFS and the European ECMWF suggest different scenarios. The GFS does not create a strong polar trough in the west and therefore never develops much low-level easterly (upslope) flow into the Front Range. Result, colder Tue-Wed, but with very limited moisture. The European Center model has been consistent with a polar trough in the West thus raising the odds of a significant snow into Colorado (mainly Tuesday). At this time I don’t feel that one solution is more reliable than the other, but I will note that the drier solution of the GFS would be more consistent with the pattern of the last 3-4 months. I will be updating this weekend.