Spring Backcountry Skiing Tip #9: In terms of avalanche danger and quality of skiing, sun heat usually influences the spring snowpack more than any other factor.
With dense cohesive maritime snowpacks such as that of the California Sierra, Northwest U.S. and BC coast range, you may have no more concern than how slushy the snow gets later in the day, with possible point-release avalanches on steeper slopes, and perhaps difficult backcountry skiing when it gets really mucky.
The picture changes with mid-continental snow. Thinner, layered snowpacks of Colorado and elsewhere can be 100% avalanche safe in the morning after a cool spring night, then transmogrify into a death trap as the snow heats later in the day. More, such snow can yield delightful backcountry skiing as the surface warms after an hour or two of sunshine, then transition to wretched breakable crust that will ruin your day.
Thus, our tip: No matter what the snowpack, starting your backcountry skiing trip early in the morning is one way to insure a wonderful day. While you can usually ski spring maritime snow all day long, an early climb avoids vile sweat sessions under broiling sun — and morning corn snow may be a bit more firm and nicer to ski than that of mid-day. And with the mid-continent snow, starting early could save your life.
How to plan your start time? Figure out your best high-point or summit arrival time, obtain sunrise time, and work backwards to your start time. For mid-continental trips on easterly exposures, try to reach your high point just after sunrise. Add a few hours for westerly exposures. If you’re skiing maritime snow you don’t have to be quite so fanatical, but time it so your climbing will happen during the cool morning hours. Sunrise times are usually available in conjunction with local weather reports. We get ours from our weather radio.