Monday and Tuesday Powder

Sunday, December 13, 2015 at 7:13 am


A strong and long-duration system will bring snow to the area on Monday, which will linger into Tuesday.  Significant accumulations are possible in some mountains.  Both Monday and Tuesday (and perhaps Wednesday) should feature light fluffy powder.  More chances for storms in the long range.


All systems are go for the storm tomorrow. Winds will be fairly strong at times today ahead of the front with increasing clouds.  Tonight, a southwest flow will bring precip to the region ahead of the front.  This should be generally light, but could favor areas like Sundance and Snowbasin that do well in a southwest flow.  During the early morning hours on Monday, the main front will arrive and bring widespread snow to all mountains.  This should continue through much of the day on Monday.  Accumulations with the front should be in the 6-12″ range.

The second part of this system will be the cold northwest flow behind the front.  This will develop by Monday evening and should bring additional accumulations thru Tuesday.  Highest totals will be in areas like the Cottonwoods which are favored by this flow.

Here is a look at the what the 06z run of the NAM puts down for the Upper Cottonwoods:

You can see the burst of accumulation Monday morning with the front, then a potential break in the action during the afternoon as we transition to the northwesterly flow.  Then accumulations continue steadily through Monday night and Tuesday.

The NAEFS ensemble suite puts down the following QPF:


Correcting for it’s tendency to be about 20-30% overdone, I’m going to say that the average ensemble is around 1.5″ of liquid storm total, which would yield 2+ feet.

Then, when applied to a map, we get something like this from the GFS for snowfall:



What this storm has going for it is a long-duration, so a long opportunity to pile up snow.  It also has plenty of cold air so the snow ratios will be high and it can pile up quickly.  What it has going against it is the risk that it could tilt and cut-off in a manner that would orient the post-frontal flow north to south rather than the northwest to southeast.  We need that westerly component in order to generate the necessary lift to produce snowfall.  I’m a bit worried that it will end up being too northerly behind the front.

With all of this information digested, I’m going to go with the following forecasted totals.

  • Beaver Mountain/Snowbasin/PowMow: 8-15″
  • Park City/Deer Valley/Sundance:  8-15″
  • Cottonwoods: 12-24″
  • Eagle Point: 10-20″
  • Brian Head: 8-16″

If the northwest flow really produces, I could certainly see the Cottonwoods topping 2 feet, but because of some of my concerns I referenced earlier, I think the more realistic approach is to keep their totals in the 1-2 foot range for now.


Both the EC and especially the GFS have some moisture returning to the area around Friday of this week as a trough moves into the Pac NW.  If we get some additional snow, it should be light.  Aside from that, we’ll gradually warm up from our frigid mid-week temps.  General trends have been to move another system into the area either late weekend or early next week.  In short, an active pattern continues 🙂



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  • PCBumpRyder

    Mr. Cold Miser commeth and I couldn’t be happier! Butterflies in my stomach in anticipation of the first “real” storm cycle of this Season. No lack of gratitude for this PC local! Merry Chistmas!

  • tybeee

    Where can I find this map at on a daily basis?

  • bwilson

    I get so curious when I read these, and then there’s always something that could skrew up the storm. How much do you think herriman could get?

    • Herriman is in the bulls eye with the models showing more of a northerly flow, thinking 10″+.

      • bwilson

        good news, i live up on the mountain up there so i will be blasted, how much do you think south jordan will get where my brother lives?

        • Now looking like 3-4″ in South Jordan and 5-6″ in Herriman.

      • bwilson

        and does that mean since is more of a northerly flow that there is not gonna be as much orographic snow?

        • Northerly flow is not ideal for the Cottonwoods but good for other areas like the Oquirrh mountains. Latest 00Z models this evening have backed off on the snow, looking more like 2-4″ valleys, 3-6″ benches, 7-14″ mountains with local 15-20″ amounts.

  • The models have been trending a little slower with a more southerly track for the last few days, both of which are not good news for the Wasatch Front. The good news is this storm is big and the snow will come, just not looking like the BIG numbers we were all hoping for in the northern Utah mountains where most ski resorts are located. It looks like for northern Utah the Oquirrh mountains will be the big winner, also looking like good snow for the Tooele valley and the west/south side of the Salt Lake Valley.

  • justdr

    Man I keep lookin’ at that tight low hitting the Alaska and the A islands, hoping it makes it’s way down here in about what, 5-6 days?

  • Justin Wehner

    Coming down pretty nicely for my night fatbike ride at 10:30 in Park City. Hoping this keeps up!