Predicting Snow Coverage Along a Route

[kdemtchouk]

I'm curious if others have gone through the exercise of looking at several trip ideas and identifying one as potentially being good for late May/early June. Since permit reservations for some of the more competitive trailheads can be made months in advance, I've started to think about how one would do this without actual snow coverage data in the weeks leading up to a trip.

It seems average snow coverage is a function of (1) elevation (higher = colder, more snow) and (2) slope aspect (N facing slopes hold snow longer, S facing slopes melt out faster).

Would it make sense to rank trips by their average elevation and % North facing miles to pick a route that would melt out faster?

I'm sure this is a simplification and there are also regional precipitation patterns dictated by topography (North Yosemite/Emigrant seems to hold a lot of snow each spring, as does the Ritter/Thousand Island area). Major creek/river crossings, as well as road access, would also be important concerns in the early season.

[Wandering Daisy]

I look at the FS snow map. Even a month ahead of your trip, you can see generally where the snow is melting earlier. I also really like CDEC data.

I have done a lot of trips with dated photos. I match these with %average snowpack data (from historical CDEC data as well as Tioga Pass data). After years of Sierra trips I have a pretty good idea of which areas are good for early season trips.

You have to look at more than snow. High creek crossings are also a big issue. I plan trips at peak flows for routes with bridges across streams. Also pay attention to opening of the trailheads (for example Grand Canyon Tuolumne is a great early trip, but you cannot access it before Tioga Road opens). I do not know if anyone has kept track of opening dates of the various trailheads in the Sierra. The only one I know of is the Tioga Pass data.

There also are a lot of cancelled permits in the Sierra, so if you are very flexible, you may be able to get one of those. This works well for solo, but not that good for larger groups.

You can also just pick a trip and then go with enough route flexibility that you can change your route to avoid poor conditions. I did this a year ago, went into Emigrant and got stopped by snow on one route, went out and got a permit for a second option and got stopped by snow on it too. But it still turned out OK, even if not what I had planned.

Also, counter-intuitively the southeastern Sierra opens up much earlier than northern Sierra even if it is at higher elevations.

Early season is also a great time to look at backpacking in non-Sierra areas such as coastal hiking (Lost Coast) or desert Southwest. Because of the difficulty in predicting snow conditions a few months out, I like to plan last minute trips in areas that do not require permits or have no trail quotas.

Another strategy is to embrace the snow and learn the needed techniques (need to be good at navigation). Even when trails are covered in snow you can usually find dry ground to camp on.

[c9h13no3]

Another strategy is to embrace the snow and learn the needed techniques (need to be good at navigation). Even when trails are covered in snow you can usually find dry ground to camp on.

I'm a big fan of this one.

The weekly satellite images on Sentinel Hub are the best for predicting conditions. Plus right now, you can see cool images of the Creek fire burning.

To me, bridges are the big thing early season. Snow is fine, I'm usually seeking it out early season (either to ski on, or cover up some terrible talus). Crossing a raging creek on a snow bridge always feels sketchy, I much prefer a giant man-made bridge.

But yeah, if you wanna do a trip early before the permits are hard to get, just embrace the snow, carry your axe & crampons, and send that sh!t.

[kdemtchouk]

All good points. I am experienced with snow travel, but raging creeks can't be solved with equipment haha.

Daisy, when you say "the southeastern Sierra opens up much earlier than northern Sierra", do you mean that eastern Sierra trailheads open up earlier because the road approach isn't as long as on the West side?

[c9h13no3]

Daisy, when you say "the southeastern Sierra opens up much earlier than northern Sierra", do you mean that eastern Sierra trailheads open up earlier because the road approach isn't as long as on the West side?

The SE Sierra is behind the rain shadow of the great western divide, and in a warmer part of the range. Areas like Miter Basin can often melt out quicker than you'd think based only on elevation.

On the equipment side: I have several times thought about getting some long 4×4 posts to build a quick bridge over Deadman Creek in the spring :-P.