Long duration winter storm starts Monday
Sunday, December 11, 2022
Temperatures are in the mid-twenties, on their way toward the forties, under bluebird skies late this Sunday morning in the Steamboat Springs area. Enjoy the warmest day of the week today as a powerful winter storm brings very cold temperatures and significant snowfall to our area starting Monday afternoon and lasting through at least Wednesday. While snowfall will diminish by Thursday, it may or may not end as another wave of cold air later Thursday keeps the chances for additional snowfall around for Friday.
A large and very cold winter storm is almost done pounding the Sierras with precipitation, with three to four feet of snowfall already reported over the past day and a half. Breezy winds from the southwest ahead of the storm today will allow temperatures to climb toward forty degrees by this afternoon, over ten degrees above our average of 28 F. With continued sunny skies, today will be the nicest and warmest day of the week.
The center of the storm is forecast to move through the Great Basin on Monday and cross the Divide overnight Monday, though the storm is so large that we should see the cold front well ahead of the center of the storm system Monday after noon. We should see some good snow showers along and behind the front, with 5-10” expected by the Tuesday morning mid-mountain report, along with much colder temperatures that will struggle to reach twenty degrees in town for the rest of the work week.
By Tuesday morning, the center of the storm should be located near northeast Colorado and is forecast to intensify and move very slowly to the northeast for a time. While winds will subside as the storm moves overhead Monday, likely limiting larger snowfall accumulations by Tuesday morning, winds pick up to be from our favorable northwest direction towards noon on Tuesday.
Crucially, the storm will be large enough to draw moisture from the Gulf of Mexico starting Monday night, and the moisture is forecast to circle the storm and be carried over our area by the northwest winds later Tuesday. Combined with the cold and unstable air mass, the resulting orographic, or terrain-driven precipitation should pick up around noon on Tuesday and last into or even through Wednesday.
There is some weather forecast model disagreement on the exact track of the winter storm, so there is uncertainty on how long the deepest moisture will stay around. I would expect 6-12” of additional snowfall at mid-mountain by the Wednesday morning report, with more likely up top.
Snowfall may taper off around Wednesday afternoon if the storm moves further to the northeast, or may continue if the storm stalls as it moves across Nebraska during the day. I’d guess an additional 3-6” by the Thursday morning report, subject to the vagaries of the eventual storm track.
The center of the storm should be around Minnesota on Thursday, leading to a break in the snowfall during the day as the atmosphere dries, but a reinforcing wave of cold air from a storm currently near the Aleutians is forecast to eventually merge with the storm and move overhead from the north around Friday. So expect the cold temperatures to persist through the work week with another round of very low density snowfall to close out the work week.
So enjoy the very cold and snowy work week in what has been already been a cold and snowy start to the ski season, and I’ll be back with my regularly scheduled weather narrative on Thursday afternoon.