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Early season snowfall correlation for Western USA

PostPosted: Mon May 20, 2019 1:48 pm
by sierra_cement
This question is more for Tony than anybody else but I think the discussion would be of interest to a lot of people. I'm curious which locations in the US have early season snow fall that's not correlated to snow fall in the Sierras.

In other words, if the Sierras are having a bad snow year, which locations have some chance of having better snow. I went through your annual data but my conclusions may be incorrect.

The chart shows correlation of Nov and Dec snowfall for a few locations. If Tahoe is having a bad early season, there is some chance that Whistler, Targhee and Steamboat to have good snow. Alta and Mt. Bachelor have some correlation to Tahoe so they are not the best places to escape a bad snow year in Sierras.

The implication is important for booking Southwest Flights. Book flights to all non-correlated areas and pick locations with the best conditions. For added insurance, book Alaska Air flights to Hawaii using British Air points as it can be cancelled for a very low cost. Convert trip to warm weather trip if it's a bad year everywhere.

correlation snow.PNG

Re: Early season snowfall correlation for Western USA

PostPosted: Mon May 20, 2019 2:28 pm
by Tony Crocker
Regional Annual Snowfall Correlations since 1973:
Region_Correlations.png (9.89 KiB) Viewed 2535 times

Yellow coded correlations are essentially nothing, the Northeast vs. all western regions for example.

Canadian Rockies/interior BC are uncorrelated to California, Utah and Colorado. The Pacific Northwest (which includes Whistler) has marginal correlation to California and the Southwest and moderate correlation to Utah and I-70 Colorado. I'm sure within the PNW Whistler will look closer to interior Canada and Bachelor closer to California. Alpine Meadows monthly snowfall is 51% correlated to Bachelor and 26% to Whistler since 1974.

All other regional combinations have significant positive correlation and the blue coded correlations are quite strong. Anyone who has skied for a long time knows intuitively that California, Utah and Colorado often have good or bad seasons at the same time. This was one of the good ones, and western Canada was conspicuously dry during the second half of the season and finished overall in the 90% of normal range.

sierra_cement wrote:Convert trip to warm weather trip if it's a bad year everywhere.

Winter is the comfortable season for nearly all northern hemisphere tropical locations. Due to ski addiction I won't do those January-March (exception made for March 2016 solar eclipse), but I have done several of them in November/early December: 4x to the Caribbean, once to Micronesia and once to Southeast Asia. Any quality skiing during that timeframe is icing on the cake IMHO. If I'm home and Mammoth gets enough snow, I'll go but I don't expect it before mid-December.

I find Hawaii a unique tropical destination without a real bad weather season. The islands are mountainous with most resorts on the leeward/dry side of consistent trade winds. I was in a Waikiki high rise for a week in August 2011, and the A/C was not necessary due to the trade winds.

As an addicted skier it's probably not a coincidence that many of my tropical trips are to the southern hemisphere to minimize conflict with northern ski season. This July will be another one of those, and as in 2010 I'll miss Mammoth's closing because of it.

Re: Early season snowfall correlation for Western USA

PostPosted: Mon May 20, 2019 4:23 pm
by sierra_cement
Thanks, Tony. The correlations are very helpful. The chart below shows the combined Nov-Dec snowfall during years when Alpine Meadows has < 70". The chances of that happening are one out of three. Dots above the black line mean they had more than 70" in years when Alpine had < 70". I have ignored the SWE and assumed that 70" is enough to have some enjoyable skiing. Certainly not for experts but I don't have that problem :D.

It is interesting to note that even Alta can fail you during a bad snow year for Sierras. Targhee, Whistler & Interior BC would be better as a backup for Xmas trips for California folks compared to Steamboat and Bachelor. Since you would need to buy the unrestricted Epic pass to ski at Whistler during Xmas and lodging can be outrageous, it is not a great option for insurance against Sierra volatility.

Booking Southwest to fly to SLC for Targhee and Spokane for Interior BC are more feasible options.

nov and dec combined.PNG

Re: Early season snowfall correlation for Western USA

PostPosted: Tue May 21, 2019 12:11 pm
by Tony Crocker
Those are the right 5 areas IMHO to analyze for early season reliability. But Targhee is the gold standard. There have been only 2 seasons under 100 inches Nov. + Dec., 79 inches in 1976-77 and 76 inches in 1986-87. Furthermore, with mostly intermediate pitch Targhee requires less snow for good coverage than Alta. To my knowledge there have been no deficient Christmases at Targhee, and I know of no other area that can make that claim.

For experts Whistler is probably the best bet. During most early seasons a base is established in the high alpine during October. So when the mid-mountain trails get covered by early December, often some of that steep alpine can open too. Extremely Canadian begins its steep skiing clinics Dec. 15, which is a vote of confidence considering what they like to ski. It is unfortunate that Whistler was known for holiday price gouging even before Vail took over. But as with Vail, skiing right before the holiday can be rewarding.

The Kootenay areas along the US-Canada border accessible from Spokane have similar weather at comparable altitudes to those in Washington State. They get plenty of precipitation but rain risk in Nov./Dec. is higher than in later months. Their data is sketchier, but by my past in-season tracking none of those places are as reliable early season as the five you have studied.