Posted April 21 6:33 am MT 5:33 am PT
Snow Stake Cams
MSLP Surface Chart thru Apr 21
All Snow
Forecast and Pattern Discussion
Here we go, the last storm for Alta before they close on Sunday. This is an interesting storm because we have all of the elements needed to overperform, but admittingly, I have thought that before and it didn’t come together. Let’s break it down.
The wave that is approaching is weakening, but there is a nice plume of moisture that should support strong snowfall along the front. We can see this on the 500 mb chart. That should give a boost to the snowfall rate. After the bulk of the moisture has moved on to Colorado, the lingering moisture should have some nice orographic lift from the northwest flow, adding a few extra inches. Will it be enough? That is the question.
Bottom line, it will snow most of the day today with a few breaks in between. The snow moves in around 9 and will last throughout the day ending around midnight tonight. Winds will be moderate between 15-20 mph with gusts in the low 30’s. Lingering snow showers are possible tomorrow morning through noon.
Colorado gets going this afternoon after the lifts close. Temperatures will be in the low 30’s for most of the resorts, with upper 20’s along the divide. Winds will be strong along the divide with gusts in the low 40’s, so bundle up it’ll feel like January.
For the central and northern resorts, winds will be pretty nice, between 10-15 mph increasing to 15-20, with 25 mph gusts in the afternoon, as the front approaches. The bullseye of this storm is along 1-70, with Vail and Aspen in the sweet spot. I expect storm totals of 4-8 for Vail and 3-6 for Aspen, with a 30% chance of higher totals (5-10 Vail and 4-8 Aspen). Resorts along the divide, Arapahoe Basin and Loveland can expect 3-5. 0-2 for the San Juans.
Nice powder day tomorrow for the central, northern and resorts along the divide with snow showers early tomorrow morning and possibly some lingering showers throughout the day. Temperatures will be in the low to mid 30’s with light to moderate winds.
Alta 888
Below is the Meteogram for Alta. It is a blend of 50 different model runs, stacked and averaged. It is pretty accurate five days out, but beyond that is FutureSnow territory. This next system has about .4 tenths of an inch of moisture, that puts us in the 4-8 range. On the high side we could have .8 tenths of moisture, which would put us in the 7-12 range. If everything we discussed above comes together it will be very close, or not. So, you’re saying there’s a chance.
We will have cold temperatures for the bulk of the storm, due to the timing of the bands occurring after midnight tonight. It will take a small miracle to pull this off. It will take some lingering snow showers tomorrow morning, to have a chance. We might end the season (Sunday) with 894.
Long-Range Forecast Prediction Chart Updated (from yesterday)
We have had quite a few busts now that it’s into full-on spring. The jet stream is oscillating between a summer-like pattern and winter, but most of the storms are still coming through.
Our unrealistic average of 93.42% accuracy rate has fallen to below 90% (89.11). Which like I said many times before this year, it is easy to have a high average, due to record snowfall.
Take March for example, Alta had more than an inch of snow on 22 days. February was more challenging, with 12 days. If you guessed it would snow on any day in March you would have a 71% chance of getting it right. In February, you would have a 43% chance. We were a 100% both months—crazy.
The Sierra is still the most challenging region to forecast for, but we have come along way into figuring out how to forecast for lake Tahoe. Including when to stop forecasting. Based on the last three years, the end of March has consistently been when the Sierra storms recede.
Once we are into summer, I will go through and break down the actual total number of snowfall days for the four regions; Pacific Northwest, Sierra, Wasatch, and Rocky Mountains.
This will give us a measure of the degree of difficulty for this year vs previous years. La Niña years are much more challenging to forecast due to less frequent storms.
This year is technically a La Niña year, but the pattern flipped La Niña to El Niño. I know it’s the chicken or the egg question, but to me, the pattern controls all teleconnections and this is just an example of that process.
Thanks for all of the emails this last week! We had some great questions that I will discuss on the blog soon. It’s awesome to have such passionate people to share the love of skiing/snowboarding with!
Thanks for reading the blog, as always if you have any questions feel free to comment below, or send me an email to Mike@FutureSnow.CO
Forecasted Areas
Pacific Northwest Cascade Mountains
Crystal Mountain, Mount Hood Meadows, Timberline, 49 Degrees North, Bachelor, Mt Baker,
Lake Tahoe Sierra Mountains
Heavenly, Palisades Tahoe, Kirkwood, Dodge Ridge, Donner Ski Ranch
Utah Wasatch Mountains
Alta, Park City, Deer Valley, Brighton, Snowbird, Brian Head
Colorado Rocky Mountains
Aspen, Aspen Highlands, Snowmass, Vail, Beaver Creek, Winter Park, Keystone, Arapahoe Basin, Breckenridge, Copper Mountain, Powderhorn, Ski Cooper, Telluride, Crested Butte, Silverton, Wolf Creek, Eldora, Loveland
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