Steenburgh winter is different from astronomical winter, which extends from the winter solstice to the spring equinox. Steenburgh winter is based on ski conditions.
Steenburgh winter begins the first day that the Alta-Collins snow stake reaches 100". That's a big number, but it represents the approximate snow depth needed to transition from early season conditions to winter conditions in the Cottonwoods. Some might think this is high, but it is roughly when most of the brush, pucker trees, and big, angular boulders are buried in the backcountry. Case in point, the Alta-Collins snow depth is just under 70", yet I hit a buried pucker tree this weekend and took quite a digger. That is a rare event once we reach a 100" base.
Steenburgh winter ends on February 10. Why February 10? It seems to be around this time of year when the sun begins to have an increasingly caustic effect on powder. Resort skiers don't notice this change (they track everything out too quickly), but backcountry skiers do. Prior to February 10, powder can linger for many days on most aspects. Even south facing slopes might survive without a melt-freeze cycle if it is really cold. After February 10, the south aspects will almost always suffer a melt-freeze cycle if the sun comes out and, as the days go on, the sun becomes an increasingly formidable enemy to powder on an increasingly greater range of aspects.
There is certainly good skiing to be had after 10 February, but it does represent an important transition point in the snow climate of the Wasatch. Therefore, it marks the end of Steenburgh winter.
This year we have a 65" base at Alta-Collins on February 10th. Hence, this is a year without a Steenburgh winter.
-----
Graphic Source: http://www.classroomjr.com/weather-coloring-pages/melting-snow-coloring-page/
so any positive signs thru mid March?
ReplyDeleteMost of the time, there is very little skill in weather forecasts of more than a week. That's the case currently. The dice are not loaded one way or the other for snowfall from late Feb-Mid March over northern Utah.
ReplyDeleteOver the next week, there are a couple of upper-level troughs moving through the split in the Sun-Wed period. I'm not strongly encouraged by these systems, but perhaps they will prove more productive than I expect. In my view, the skiing the past couple of weeks has been decent, if we can get a modest snowfall, it will help keep that streak going.
A web page that is pretty useful in regard to sun angle, etc is http://aa.usno.navy.mil/data/docs/AltAz.php. On February 10, our maximum sun angle reaches 35 degrees above the horizon (compared to just under 26 degrees on December 21). By April 1, the maximum sun angle here reaches 54 degrees... a very large increase from early February.
ReplyDeleteLet's get a less depressing post up!
ReplyDeleteWherever I've lived and skied (Utah, Montana, Alaska, Maine), it's funny how these places only just barely get enough in the peak of the season to cover up nearly all obstacles. Utah needs 100" snow depth, but here in Maine, we get less snow, but it only takes about 16" depth to cover everything. Alaska was much snowier, but it also took about a 100" snowpack to cover up everything. Is there anywhere that averages 500"+ snow who only needs a foot or two to cover most obstacles?
ReplyDeleteYes. There definitely are. When the following ski areas have at least a 2 foot base, they present with less rocks, brush, roots, and hazards than when Alta/Bird's base is anything less than 80", yet the following ski areas average over 500"/year.
DeleteMt. Baker, Oregon
Cortina, Japan
Solitude, Utah
Asahidake, Japan
Niseko, Japan
Norikura, Japan
Kokusai, Japan
Hokkoda, Japan
Tsugeike, Japan
Rasutsu, Japan
Grand Targhee, Wyoming
Brighton, Utah
Stevens Pass, Washington