Tuesday, March 10, 2015

Could This Be the Least Snowy Season on Record at Alta Guard?

I've been taking a look at the medium range guidance out to 10 days and we get what looks to be a weak storm on Wednesday night and Thursday, after which the pickings are pretty slim.  There's always the chance the models are wrong and we do better than advertised, but for the most part, the pattern remains locked in.  The forecast below for next Tuesday afternoon shows a monster split over the west with the ridge over northwest North America and the trough over eastern North America.

Source: NWS
Do we have a shot at the least snowy cool season (November - April) on record at Alta Guard?  Based on data on the Utah Avalanche Center site, this season has brought Alta Guard 196.5 inches of snow from November to February.  I'm not sure how much they recorded during the storms in early March, but Alta ski area reported 27 inches, for the sake of argument, let's assume Alta-Guard got something near that and will get enough snow during the approaching mid-week storm to give them 36 inches for the month.  This brings them up to 232.5 inches. Based on the medium range forecast, lets assume thats their total through the 15th (mid month).

If they were to get average snowfall from mid March through April, that would be another 113 inches, yielding a seasonal total of 345.5 inches.  That's well above the record minimum of 314.5 inches.  To break the record, they need 70-75% of average snowfall from mid March through the end of April.  A quick eyeball of past data suggests there's about a 35% chance of being that far below average.

Do you like those odds or would you bet on the persistence of the pattern and weight the odds higher to perhaps 50/50?  Or, do you drop the odds lower because the Climate Prediction Center 3-month outlook is giving us somewhat better than climatological odds of above average precipitation for the period?

Source: CPC
Well, what say you?

6 comments:

  1. Based on our season thus far historical averages are meaningless and I predict the record for the least snowy season will be broken. And even if we do get decent snow at the end of March/beginning of April, it's not going to all of a sudden make everything better. We still need to build base at the resorts (I picked up two core shots in two days at Solitude last Tues & Wed) so at this point I'm ready to put this winter of frustration behind us and move on.

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  2. I don't know if this is true or not, but it seems like perhaps we are more likely to get locked into some type of blocking pattern during the core winter season (Dec - Feb) than in the spring. If so this may be related to the location of very cold arctic air masses (such as the climatological Hudson Bay low) and their persistent nature. In any case, I think the transition from winter to spring changes a lot of variables, so that a pattern which has been dominant may change with the season.

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  3. Is past performance an indicator of future results?
    After 25 heads, am I more likely to see a tail?
    Just a question... I would bet on low snow but my parents are statisticians...

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  4. I'm an obligate snowboarder. Why are we talking about Alta all the time?

    (I am an honorary member of the Alta Snowboard Team, just in case some of you know what that means.)

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    1. This is a good question. My focus on Alta is more for convenience than anything. I have a limited time to do posts and, because they have the longest records and a really solid snow measurement system, its my best option. It is also the only upper-elevation site in the Wasatch with easily accessible snowfall records (Silver Lake – Brighton has such observations, but Alta's are easier to get to).


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    2. I've skied and/or ridden over 100 lift served areas; been skiing since '69 and boarding since '83 -- I sure know that some areas have good reports and some really, really don't.

      Thanks for the good, clear answer.

      By the way, I'll be playing second trumpet in the pit for "Funny Thing Happened on the Way to the Forum" at the Babcock Theatre in April. There'll be at least 14 public performances centered on week-ends from April 3rd through the 19th.

      If we have a rainy, no good for skiing, week-end stuck in there, come get some culture.

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