A cold storm will bring snow to all mountains on Thursday and Thursday night. Friday will be cold then the weekend will be warmer and dry. We will then have a chance for a storm next Mon/Tue and again on or just after Thanksgiving. The week after Thanksgiving may also bring 1-2 storms.
Short Term Forecast
Here is the morning radar loop from about 4am to 6am on Thursday, showing what is actually happening in the atmosphere. The leading edge of a line of heavier precipitation (white and bright pink colors) is entering the left side of the image, crossing the Utah/Colorado border.
As the storm moves across Colorado, so will the heavier precipitation. The loop below is a forecast from the high-resolution HRRR model. It stretches from 4am Thursday to 7pm on Thursday. Notice how the initial banded and convective precipitation (oriented from south-to-north) transitions to smoother, orographic snowfall from a cold northwest wind. Also, notice a time of heavier precipitation in the north-eastern mountains.
Expect snow to start between about 9-11am for most mountains, with snow continuing off-and-on through midnight on Thursday. Roads will likely be snow covered on Thursday and Thursday night. Some snow may even accumulate in the Denver area, though most major roads near the city should be fine with the exception of I-25, which could be snow covered for areas south of Denver on Thursday evening.
The snow forecast from the American GFS model is generally unchanged from yesterday. Most mountains should see 3-6 inches, with less in the southern San Juans and potentially more near and north of I-70 and along the continental divide (the purple area north of Eldora signals a chance for higher amounts near and along the divide...see the "geography key" at the bottom of the post).
The high-resolution CAIC 4km WRF model is more bullish (below), averaging 7-10 inches for the central and northern mountains with some areas at or above 10 inches. I think the northern divide, around Rocky Mountain National Park, Cameron Pass, Winter Park, and Berthoud Pass may have the best chance to see the highest amounts.
The CAIC 4km WRF model is often too optimistic. But, these amounts are in the realm of possibility IF the storm slows down, or IF the initial bands of snow during midday Thursday produce a lot of snow, or IF the orographics really kick in on Thursday evening. This storm has a limited amount of moisture, and since moisture is the fuel for snow, I would tend to look at the lower end of the range rather than the top end of the range.
Let’s look at more snow forecasts…
This is a point forecast from the CAIC 4km WRF for the area around Vail Pass, Copper, and Breckenridge. The total is 4-5 inches.
And below is a point forecast from the NCAR 4km WRF Ensemble for the same area around Vail Pass, Copper, and Breckenridge. This model runs 10 times with slight tweaks so it can output a range of forecasts. The range is roughly 3-4 inches.
The snow on Thursday and Thursday night will be fun to see, but the more important part of this storm is the cold. Temperatures will drop into the single digits on Thursday night and will NOT get above freezing for most mountains on Friday. This means snowmaking can crank up!
Nothing but good news for the long-range outlook.
Friday, Saturday, and Sunday will be dry but cool. Most resorts should be able to make snow at night.
Another storm will bring snow from midday Monday through Tuesday (Nov 21-22). Unlike today’s storm, the storm early next week will have a LOT of moisture, so snow amounts could be higher, especially in the southern and central mountains. Here is a snow forecast from the University of Utah for Wolf Creek, in Colorado's southern mountains. The average of the forecast lines shows about 10 inches next Monday and Tuesday.
Next Wednesday should be dry, so driving or flying to friends/family for Thanksgiving will be OK.
The next storm should bring snow late on Thanksgiving or Friday (Nov 25). I don’t have much confidence in the track of this storm, but snow is very possible.
Annnnnd…two storms are possible during the week after Thanksgiving, with a cold and stormy pattern likely continuing for the first week of December.
If all of these storms materialize, we will begin to chip away at our snowfall deficit and I am cautiously optimistic that we’ll have plenty of snow on the ground by mid-December.
Enjoy Thursday’s storm and thanks for reading!
I will be giving a talk at Tin Shed Sports at 112 E 2nd St. in Nederland TONIGHT on Thursday, November 17th. There should be snow on the road around Nederland ... drive safe and enjoy the flakes! Come at 630pm to eat tacos (their food is great!) and have a beer, then I’ll start my talk at 700pm. We’ll chat about this week’s storm, the outlook through early December, and a few thoughts on the season. More event info: https://www.facebook.com/events/1711488562505488/ and link to Tin Shed Sports: http://www.tinshedsports.com/
Steamboat, Granby, Beaver Creek, Vail, Ski Cooper, Copper, Breckenridge, Keystone, Loveland, Abasin, Winter Park, Berthoud Pass, Eldora, Rocky Mountain National Park, Cameron Pass
Along the Divide
Loveland, Abasin, Winter Park, Berthoud Pass
East of the Divide
Eldora, Rocky Mountain National Park, Cameron Pass
Aspen, Sunlight, Monarch, Crested Butte, Irwin, Powderhorn
Telluride, Silverton, Durango, Wolf Creek (Telluride and Silverton are on the northern side of the southern mountains)