Confidence Growing

Saturday, December 12, 2015 at 7:30 am


A storm will enter the region Sunday night into Monday with significant snowfall possible.  All Utah mountains will likely see good accumulations with the highest totals in the Cottonwood Canyons.  Very cold temperatures and snow levels down to valley floors will accompany this system.


A few very light snow showers in Northern Utah this morning.  These should clear up quickly.  Our cold front from Thursday evening dropped south to Southern Utah where it stalled yesterday.  Good snowfall totals are being reported down at Brian Head where they’ve seen 14″ in the last 24 hours.  They have been having a good start to their season.  Trips to Southern Utah are definitely in the cards this winter!

The last two days, I mentioned that I would wait until Saturday before getting invested/excited for the upcoming storm.  We’ve had some poor luck with the way storms have evolved so far this season and it was prudent to wait until we were within closer range and therefore had more confidence.  I’m happy to report that models have stuck with the idea of this storm being a good one for Utah mountains.  If anything, they’ve trended a bit stronger in the last 24 hours.

It looks like the cold front will enter the area late Sunday night.  Snow should start in the Wasatch during the wee hours of the morning on Monday.  Widespread snow should continue through Monday morning.  I’d expect several inches at most resorts by the time the lifts start spinning with the snow getting deeper throughout the day.  By Monday afternoon, the snow should taper to showers.  This storm looks to have a good prolonged period of a northwest flow that will hopefully keep snow showers going thru Monday night and possibly into Tuesday.

As for snowfall totals, I think most Wasatch resorts will be in the 6-12″ range by the end of the day on Monday.  The trough will then linger over the area through Tuesday and likely bring an additional 3-6″ for most area.  The Cottonwoods, which are more favored in the northwest flow, could see an additional 6-12″ Monday evening thru Tuesday.  So… in total I’d say 8-16″ for most Wasatch mountains with 1-2 feet for the Cottonwoods. Southern Utah mountains should see 6-12″ of snow as well.

In support of these numbers, let’s look at the QPF from the NAM:


This is for the Upper Cottonwoods. You can see the precip starting around midnight on Sunday night and falling heavily through noon before changing to more gradual accumulations through Tuesday morning with over an inch of liquid total.  At an average of 18:1 ratios, that would yield close to 20″ of snow.

The NAEFS ensembles are in good agreement with this storm:

Similar timing of the onset of precip for most models.  These models give a QPF range of 1.5″ to 3.0″.  I’ve said before, I think this is generally over-done.  But still, it demonstrates that almost all ensembles are in agreement in at least a decent snowfall event with a good chance for it to venture into “significant” territory.  Significant of course is a subjective term, but I’d say most of us would agree that if we have a chance for a couple feet of snow in the Cottonwoods, with a foot or more elsewhere, that counts as significant.

As for temperatures, they will be cold.  Single digits and teens in the mountains behind the front on Monday, with the cold air likely lingering through mid-week.  This cold air also means that snow levels will quickly drop to valley floors.  I don’t do much forecasting for the valleys, but I’d expect that commuting, perhaps even getting to resorts on Monday morning could be a bit tricky with heavy snow falling at all elevations.

Overall, I’m feeling confident that we’ll have a good storm.  Just glanced at the latest 12z NAM and it still looks good.

Models are not in good agreement later next week.  I don’t see any additional major storms, but at the same time, there is no sign of persistent ridging so the pattern should remain active right up through Christmas.


P.S.  As always, please consult the Utah Avalanche Center if you plan to venture in the the backcountry during or after the upcoming storm.  The storms in November have turned into a weak, rotted base.  Good chance the snowpack will be unstable for awhile after this storm.

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  • Matthew Crain

    Thanks so much for these forecasts! Definitely read them everyday! Still thinking that most if not all of the terrain at PC should be open by Jan. 2? Their open terrain right now is super limited…if we postpone this trip, we will plan on coming back to PC the week of March 11 but changing plans is not ideal for us and it would cost extra dough.

    • Yep. They are pretty close to opening a lot more terrain. Add in some natural snow, man-made snow, higher demand from holiday crowds, etc…. They’ll have most, if not all, of the mtn open by then. That’s my opinion at least.

      • Grant

        Plan on visiting Utah for the first time on Jan 3rd from Ohio, is PC normally fully open by then?

        • Justin Wehner


    • Also… PC currently has 17 lifts running. I wouldn’t call that “super limited”

    • Matthew Crain

      A lot of those lifts aren’t the major lifts (bunny hill, terrain park lifts, transfer lifts), and from each of those lifts, only 1 or 2 slopes are open. But true perhaps I should call it ‘limited’ instead of ‘super limited’!

  • P Gee

    whew, it’s good to see this update — we almost cancelled our trip to BCC for next week & even though Solitude will still be thin on open trails post storm, maybe it will make what’s available palatable…thanks for keeping us advised!….

    • Was at Soli yesterday. They could definitely use a good storm. Looked like they were planning to open Powderhorn this weekend. Hopefully the new Summit Chair will open soon-ish.

      • P Gee

        Very helpful – thanks!…would be great to have at least powderhorn open…and if we were to get more snow later next week…maybe the summit chair could open…

  • Gretchen

    Snowbird is currently at 31 open trails. Can anyone share their opinion on how many trails might be open with this storm? I’m guessing it won’t be enough to open the back side, am I right? ALL VERY exciting regardless… Thanks for the update!!

  • Dave Raue

    Great news! Since it’s still early in the season any thoughts on how this storm might bring up the cumulative average for the season? Seems like a good storm or 2 ought to bring seasonal totals closer to average.

    • The Snowbird snotel site currently has 4.2 water (average for this time of year is 7.5) which is 56% of normal. If this storm adds 2.5 water to the snowpack we will be around 85% of normal by the time Wednesdays numbers come out.

      • I would take 2.5″ of SWE. But I think 1.5″ is probably more realistic.

        • I agree 1.5″ of SWE is more realistic for this storm which would put the Snowbird snotel site around 73% of normal by next Wednesday morning.

  • Chad Niel

    I need help planning here. I’m gonna burn a vacation day to ski next week but I can’t decide if monday or Tuesday will be more sponge worthy. Thoughts?

    • Tough call. Where are you skiing at? Any chance you could “burn” a vacation day, then contract an unfortunate “illness” that forces you to take a sick day on Tuesday…?

      • Chad Niel


        LOL, Unfortunately I have screwed myself at my job. No one would ever believe I was actually sick on a powder day haha. Next job im goinf to constantly tell everyone how much I hate winter 🙂 I’m also definately not in two day in a row shape yet having only skied three trams yesterday and hurting everywhere lol.

        I can make the call Sunday though so hopefully by then we will have some confidence in the monday night total. If even 6 inches falls on top of a whats there Monday after the lifts stop turning i would think Tuesday for sure.

        By the way, I love love love love your blog. It’s so much better than just looking at the 7 day change twice a day and trying to divine what it means. I also appreciate the realistic approach to forecasting. This site is easily the best in the state!

        • I’m in a similar boat as you. Monday will be nice because it will keep getting deeper and the heavy snow and poor roads will scare away a lot of the skiers. Also, the totals reported early Monday morning will be small, so you won’t have the same knee-jerk response to get into the mountains. But, as you said, Tuesday will have snow on top of snow, so it’ll be deeper!

          Subtle shifts in timing will affect this so stay tuned thru tomorrow.

  • Jim

    The 12z GFS continues to look good out 384hr with several opportunities for decent snowfall. In fact 0z and 6z runs today also show decent snowfall amounts out 384hrs. I haven’t seen this much accum. snowfall for the Wasatch in the 384hr forecast in a very long time. I know it’s very long range and highly speculative but the trend is there. Does the euro weekly long range share this optimism at all?

    • Absolutely right about the GFS. Unfortunately, the EC isn’t nearly as optimistic at this point, but with how consistent the GFS has been, I’m hoping it’s on to something. New Euro is coming in as I type, so hopefully we’ll see…

      • Jim

        Does the weekly euro long range still come out on Friday’s ?

      • Steve Noufer

        Does EC show any snow in the long range? I’ve been watching the GFS model runs and they’ve been pretty consistent in showing an active pattern to end of run. Just wondering how much they diverge.

  • eb295

    Just want to say that your site is like a great suspense novel…I wait every morning for the latest updates even though I only ski a bunch in UT. Also, can’t tell you how much I learned about climate and weather prediction from you – absolutely fantastic writing.

  • Kai V

    Hey dude thanks so much for doing this. keeping up with everything from wisconsin is tough, especially being a Utah native at heart! Coming in over winter break, (19th-jan 3rd) is there gonna be enough snow to open up the tram at the bird and more of the mountains in the other resorts?

    • I believe the Tram is running now… Right now it looks like a lot of snow is on the way over the next 10 days. I’d expect everything to be open.

  • Justin Wehner

    At this point, if Evan is even vaguely enthusiastic about anything, I am ready to actually wax skis. That’s right.

    Who wants to step up and pay me not to get the iron out? Seriously, I’ll do it. I’m warming it up now. I could ruin this for all of us, it’s in your hands…