I guess it's officially summer.
Yep, you figured out my secret motive! Although it's a chilly gray summer day here in Portland... making random ski musings even more attractive
Is your goal to figure out snow quality from one place to another? Season length? Because you've basically moved us up with Colorado here to 11000 feet. (Now, clearly, you'll have much more OXYGEN here than that.) But, as you go higher, the snow is going to be drier as it's just sublimating into the atmosphere instead of getting wetter and packing. We have far drier snow than the coastal regions, but we rarely get the three foot deep dumps that you blast through like feathers. So that chart is really really deceptive in that regard. Our snow staying power might be equivalent, but a lot of that is lack of people and the amount of trees. Snow depth? Um, no, we generally have a deeper base than Big Sky. So I'm not sure what you're trying to go for.
All valid thoughts. And I suppose I didn't so much have a clear idea of what I was trying to measure as curious about what this might reveal. And maybe part of that is a comeback to "Whitefish? No thanks, the summit's not even 7k." We can respond with "Yeah, but it's the equivalent of over 11k in Colorado."
Tony Crocker would be a suitable person to contribute to this discussion but..................
Anyway I think orientation (very much north facing terrain) plays a massive part and it explains why Mammoth has such a long season despite it's latitude.
@TonyC would love this topic....
Agreed. Re: Mammoth, the north-facing terrain matters a lot, and so does its anomalously-favored topography (snow funnels in there, much like at Wolf Creek, which would be #26 on this list).
He's talking about the difference between
pressure altitude and surveyed altitude. The further north or south one goes the same surveyed altitude will show lower air pressure than at the equator. It is a real effect - it is a mountaineering trope that climbs in Alaska are not altitude-comparable to climbs in Himalaya or on African volcanoes....
That's interesting, something I hadn't realized, and contributes at least a bit. But I think the lower-angle sunlight at higher latitudes is a much bigger contributer to temperature differences.
And I actually think that the rule of thumb he's trying to remember is concerned with TEMPERATURE.
https://sciencing.com/info-8686864-latitude-altitude-affect-temperature.html
Agreed. Temperature is the variable most directly influenced by the conjunction of altitude and latitude, I think. Of course, comparing average temperatures will only get you so far re: ski quality, but it's something.
My observations are that (generally speaking, because there are all kinds of microclimates around mountains), 300 miles of change in latitude is roughly equivalent to 1000’ in elevation change.
So, where I ski at Stevens Pass, latitude 47* N (plus some change) at an altitude of 4061’, is similar to Lake Tahoe at 39*N at an altitude of 6225’, roughly 700 miles as the crow flies. Similar snow quality and density, in any event.
I created a new tab on the spreadsheet (
https://1drv.ms/x/s!Ag3jxxfR7xEGjJxJSdPmbCAZrEPnTQ for anyone who wants to play with it) using this 1000' per 300 miles metric. Interestingly, this makes Stevens Pass show up
below all the Tahoe resorts (using 500' per degree put it
above all the Tahoe resorts). Maybe a number somewhere between these two is appropriate, at least for the Stevens Pass - Tahoe comparison?
So in a nut shell, you're trying to use your chart to tease out snow quality.
But oddly ending up, not with Utah at the top, but Big Sky? Umm.. Well I personally agree it's better here (or at Big Sky if I must) for various reasons, but I'm not sure that you're going to get anyone else to agree that Utah should be so far down the list. Because popular thought is that lighter is better.
Screen shot of partial list for easier viewing.
Good call on the screenshot... I was trying to get the table to show in the post, but I didn't manage to think of such a brilliantly simple solution
But... Colorado's (and probably Big Sky's) snow is
lighter than Utah's.
Jim Steenburgh has made that point repeatedly in his book and blog. Colder temperatures (Colorado, Big Sky, Jackson/Targhee) likely make for better snow durability, particularly as it gets later in spring. They're also somewhat correlated to lower rain chance, although above some level (maybe 8,000' or so at 40 degrees north?) rain isn't much of a concern.
In thinking about your goal, maybe don't call those numbers normalized altitude going forward, but "points". Now apply a penalty for closeness to the ocean. Because that might swing Utah higher and penalize some of the places impacted by the snow not drying out like it does as it gets further from the coast.
Except that snow
quantity is a very important component in overall snow quality, and quantity generally increases with proximity to the Pacific. Penalizing proximity to the ocean would push the scores up for Colorado and Jackson/Targhee, while significantly lowering it for Tahoe/Mammoth/Bachelor. That seems less accurate to my eye.
I've heard a similar rule of thumb (don't know if it was exactly the same number) in the context of the change in the types of vegetation as you go up the mountain.
The point is not to use it as a complete proxy for snow quality -- snow itself is a pretty good measure of snow -- but rather as insight into the balance between being located more to the North and being higher.
If you want to go beyond, "hey this is a cool observation" the next step would be to grade the actual snow quality of each ski area as better or worse than implied by its normalized altitude.
Agreed. And I'm not in the market to try to put together a better ZRankings, but someone certainly could
Maybe add distance to the ocean to the points so far? Or some fraction thereof? You can't just use longitude since the coast moves around.
Maybe cheat on determining that number... Figure out the number you need to move Alta to the top. Then measure the distance of Alta to the coast. Use that relationship against all the coastal distance numbers and see what you get. Just spit balling here...
If you don't have another app for that,
this might help. Distance from Alta to Female, CA is 663 miles. Distance for Big Sky to Pacific City, OR, is 616. There might be better tools, tho.
Yep, further spitballing… I think proximity to the ocean would be a good penalty if the overall metric also factored in average snowfall. Together with the altitude/latitude data, those factors seem like they could be balanced to move Alta, Snowbird, and Grand Targhee up close to the top, at least.
