Sunday, December 3, 2023

And So It Continues

The skiing and snowpack situation yesterday was somewhat better than expected, making for a decent day with some deep powder.  Many people were out and tracks were laid all over upper Little Cottonwood and environs.  

A noticeable density inversion lied beneath a couple of inches of low density powder that fell just before and while we were touring.  Call me a snob, but I felt that made for "hard rock" powder skiing rather than "easy listening."  One definitely had to think about keeping the skis from diving.  

The storm continues today and I've elected to work rather than fight Mother Nature in the backcountry or  lift lines at the resorts.  I suspect for the former, the snow is too deep for good skiing on the sub 30 degree slopes I'd be inclined to ski today and for the latter it may take some time until terrain is opened and then it will be limited.  

As of 8 AM, the Collins stake at Alta has recorded 9 inches of snow since midnight with 1.01" of water.  If these measurements are accurate (and they could be off some due to the wind), that's a water content of 12.1% and in the Sierra Cement territory.  So, the new snow is upside down and we've now added weight rapidly to a weak snowpack with more on the way.  

The latest radar mosaic shows precipitation echoes extending northwest from northern Utah all the way up into the Pacific Northwest.  Echo free areas reflect poor radar coverage rather than precipitation gaps.  

Source: College of DuPage

Thus, we will keep the precipitation train rolling in the mountains today, with some modulations in snowfall intensity as weak waves in the flow move through. 

The 12Z HRRR is putting out another 1.2" of water and 10" of high density snow from 5 AM this morning to 5 AM tomorrow morning.  About 0.2"/2" of that was through 8 AM when I am writing this, so that would translate to about another 1" of water and 10" of snow.  

For the same period, the 6Z GFS (the 12Z isn't in yet) is around 1.15" of water and 10.2" of snow, so a tad wetter.  Seems like another 1-1.25" and 8-12" of snow is a reasonable expectation.  Expect snow to liquid ratios to generally be 10:1 or lower.  

The mountains will look and ski very different come tomorrow.

1 comment:

  1. Nice storm. You know anything about Lois Meadows in City Creek? Elevation 6700, on Google Earth its about 1.7 linear miles up canyon from Rotary Park.

    If snotel is to be believed, Lois Meadows got 2 inches of water and 10 inches of snow between 5pm yesterday (Sat 12/2) and 2pm today (Sun 12/3). Snotel reports 21 inches on the ground.

    City Creek can be a cold pool, not Peter's Sink, but colder than you'd think

    Cum precip is above median but cum SWE is below median (as of official chart 12/1) reflecting relatively warm flow this year. SWE is nearly median in the hourly data this afternoon.