Yesterday's and last-night's storm delivered in spades in the Wasatch Range. The Utah Avalanche Center reports 8-17" since yesterday morning with the highest amounts in upper Little Cottonwood. Given the faceted, weak snowpack that existed prior to the storm, a backcountry avalanche warning has been issued for the mountains of northern and central Utah.
Data from Alta-Collins suggests a storm total of about 17" if one adds up the 7 inches through 1600 yesterday, when the board was wiped, and then the 10 inches overnight. The heaviest snowfall was from about 1600-1800 when 6 inches fell with about .24" of water content.
Several of my University of Utah colleagues in Mechanical Engineering and Atmospheric Sciences, including Trent Meisenheimer (also affiliated with the Utah Avalanche Center), Tim Garrett, Eric Pardyjak, and Peter Veals are running a suite of instruments in the Alta area this winter. Some of the data they are collecting is simply spectacular. Below, Tim provides a tweet of data from the Differential Emissivity Imaging Distrometer or DEID. Without getting into details, this instrument provides frequent measurements of the density (% water) of falling snow. The plot he shares below presents the data in a way that resembles a profile through the depth of new snow, in this case the accumulation through 1833 MST. It shows very nicely that the initially (bottom of the graph) the snow was about 7-8.5% water content, but the water content decreased with time and for most of the storm through 1833 MST, it was in the 5-7% range.
— Tim Garrett (@nephologue) December 18, 2020
I don't have data for overnight, so I can't comment on that period.
We really needed this storm and hopefully it will help a lot. The Alta-Collins snow depth sits presently at 43". I use 40 as the threshold for the start of real "early season" skiing, although we may settle to below that in the next day or two.
One forecast shortcoming was that it warmed just enough yesterday that precipitation fell as rain at the lowest elevations, limiting accumulations. Commuters probably appreciated that, but I didn't :-). I'm also not sure if Mountain Dell got enough snow for Nordic skiing to get off the ground there. The weather station there shows only 0.12" of water from the storm. If accurate, that's maybe an inch or two of snow.
It's looking like January at least for Nordic, unless you want to go hit Soldier Hollow. PC in town got 2-3", I can't imagine Mtn Dell did any better.
ReplyDeleteLooks like maybe 8" in North Fork. I'm not sure that's enough for them, but maybe. Spruces should go.
DeleteI have some shoulder issues right now and I'm not sure how well I could do skating but I was hoping to try and get out one or two days a week during the break. It's a real bummer with COVID not to be able to skate ski as its about as safe as low risk as it gets. I'm sick of walking and hiking.
Freeskating is good for you anyway, just leave the poles at home.
DeleteIt's been depressing trying to keep the nordic kids entertained so far. I was really hoping for a good dump at lower elevations.
Yes, I've been thinking of freeskating. It's hard enough though skiing with poles! However, I suspect skiing without them would be about the best thing I could do to improve technique and balance. I don't use my legs enough.
DeleteWow, that DEID data is awesome.
ReplyDeleteHappy to find this info. Planning to bring my two boys for first ever Alta skiing and still praying for snow....in fact, still not sure it's worth the expense given snowpack levels. Reasons for believing more snow on the near horizon? You noted 40" rule of thumb for early season.... Any rule for seeing Baldy, etc open? Thanks much, great info, Chris
ReplyDeleteBaldy is a tough call. Alta has gotten it open more frequently in recent years and main chute probably has enough snow, but the avy conditions are pretty tricky right now.
DeleteThanks Jim, here's to hoping for good things next week. Hard this early I know.
DeleteJust moved to the area from the midwest and am an avid meteorology and skiing nerd. Glad I found your awesome blog, keep up the good work!
ReplyDeleteGlad you like it.
DeleteJim, I groomed Friday morning Mtn Dell. We got 4-6" high water content snow. A lot of folks skied it Friday, although it was v/soft. It was groomed again Friday evening, set up Friday night and skied very well today. When I left today (Saturday) Chris was heading out to snowblow more snow into the classic tracks.
ReplyDeletesteve
My son skied there on Friday and reported the soft conditions. I am heading up for a short skate today to see if the shoulder can deal with it. Thanks for the efforts!
Delete