Thursday, January 19, 2012

Return of the Greatest Snow on Earth

Surely you remember why we ski in Utah?
I'm not up skiing today, but suspect those who are are scratching their heads and wondering who transported them from the Wasatch Mountains to the Cascades.  Actually, the snow in the Cascades is probably better as they've had a streak of cold, snowy conditions over the past few days (culminating with a debilitating ice storm today in the lowlands of western Washington).

Here's a statistic for you.  Based on the snowfall history at Alta.com, last night's storm was the first to produce a daily (24-h) snowfall of 10" or more since 31 October.  Now I consider 10" to be the minimum amount of snow required for deep powder skiing since you need about that much before you start getting true ski floatation.  Given that the 13" we got overnight was Cascade Concrete, that essentially means that there hasn't been a good deep powder day in almost 3 months!

That will change this weekend when the Greatest Snow on Earth finally returns.  Through Friday night, the wet, windy, and warm regime will dominate with some periods of higher density snow in the Wasatch and rain in the Salt Lake Valley (benches may see some snow mixed in at times).  The weekend storm, however, looks great.  In the latest GFS forecast, it starts out warm with 700-mb (crest level) temperatures around -5ºC at 11 am Saturday.


Then the trough goes through and temperatures fall, reaching -14ºC by 5 am Sunday morning.


That's a perfect recipe for a right-side-up storm.  The decline in temperature during the storm means some higher water content snow to start, but a transition to lower water content snow over time, which is ideal for deep powder skiing.  The Alcott snow density algorithm presently calls for 13-14% water content snow on Saturday morning, declining to ~5% by Saturday night.

Things could start out manky on Saturday, but if these forecasts hold up, Sunday will be the first good powder skiing of the year.  I know I'm going to regret saying that...

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