As ski resorts begin to close, more skiers flock to the backcountry to savor the last taste of winter. Spring can be a time of long days and fun ski missions in the sun, but caution must still be exercised as springtime snowpack can be dangerous and variable. Last week, Western Canada had a notable trend toward higher avalanche danger due to warming across the region.This week, Avalanche Canada has posted a warning that indicates rapidly fluctuating levels of avalanche danger. In some regions west of the Canadian Rockies such as Glacier National Park, The Kootenay Boundary, The Purcells and the North and South Columbia regions, avalanche danger remains High above treeline, fading to Considerable and Moderate in certain areas below treeline. Along the Rockies, Avalanche Canada has issued a warning for many regions that indicates a highly variable snowpack.
On Thursday in the Kananaskis region the forecast warned of daytime warming that could lead to high avalanche danger.
“The avalanche danger is variable and can range from Low to High,” explained the forecast on Thursday for the Kananaskis region. “Traveling early in the day is recommended, as conditions can change rapidly in short periods of time due to daytime warming. Pay careful attention to the integrity of the surface crusts formed overnight and rising air temperatures during the day. Dry slab avalanche danger may also exist during spring snow storms.”
In the U.S., springtime conditions show similar signs of daytime variability. The Utah Avalanche Center is reporting most forecasting zones with a Low Avalanche Danger rating except for the Logan area, which is rated Moderate with spots of Considerable above treeline and on south facing slopes. These areas of higher avalanche danger are also due to a warming snowpack late in the day.
And in Colorado, variable conditions exist with lower danger in the morning giving way to Considerable danger in the afternoon, when the sun is able to wreak its havoc on the snowpack.
The Crested Butte Avalanche Center released a video highlighting the concern for wet slides in their recent video:
The Northwest Avalanche Center is forecasting Considerable avalanche danger for all zones, warning of “Heat-related loose wet avalanches, cornice releases and glide avalanches.”
This consistency across avalanche forecasts continues up into Montana where the Gallatin National Forest Avalanche Center warns of the same flip-flop in avy conditions throughout the day. Conditions remain at a Low danger level in the morning, but once the sun comes out, ratings jump to Considerable.
The bottom line is that conditions are highly variable in the spring, with temperatures sometimes fluctuating 40 degrees or more. Be prepared for anything from crust and ice to wet slab avalanches. Stay equipped with proper rescue tools and to undergo avalanche education before venturing out in the backcountry.
For a full report on U.S. avalanches, visit the Colorado Avalanche Information Center website and your regional avalanche forecasting service. For Canadian avalanche forecasts, visit www.avalanche.ca.