This is Ian Hoyer with the avalanche forecast on Friday, April 18th, at 7:00 a.m. sponsored by Montana State Parks and Gallatin County Sheriff Search and Rescue. This forecast does not apply to operating ski areas.
Since yesterday morning, 3-6” of new snow fell around Big Sky and West Yellowstone, with 1-2” across the rest of the advisory area. Winds are 5-10 mph out of the north and east, with gusts up to 30 mph. Temperatures this morning are in the single digits and teens F.
Today will be mostly sunny, with any lingering clouds clearing up by mid-morning. High temperatures will be in the 20s and 30s F. Light winds will continue out of the north and east, blowing a bit harder around West Yellowstone and Island Park.
Expect sunny skies again tomorrow with temperatures rising a bit higher before snowfall returns on Sunday and Sunday night.
Today’s avalanche concerns are all going to within the 5-9” of new snow that fell since Wednesday morning.
Wind Slab avalanches are the primary concern. The new snow has been drifted into cohesive slabs by north and east winds since snowfall began. With an easterly component to the winds, be on the lookout for drifts in unusual locations. Some of these drifts will be easily triggered today and some will have already started to bond. Steering around the deepest wind drifts is an easy way to avoid much of the avalanche hazard today. You can also quickly dig down to check how well they’ve bonded to the old snow surface. Cracks shooting out in front of your skis or sled are clear signs you’ve found an unstable drift.
With clear skies today, the new snow will get wet on sunny slopes and you’ll be able to trigger Wet Loose avalanches. These slides will run on top of the hard crusts underneath the recent snow. Feel for the snow surface getting wet and sticky and look for rollerballs and pinwheels as clear signs that Wet Loose avalanches are imminent. Most of these slides probably won’t have enough volume to bury you, but they can still be surprisingly powerful, plenty strong enough to push you off a cliff or into rocks. Plan to move off steep sunny slopes later in the day, as the snow gets wet.
With both wet and dry avalanches possible, the avalanche danger is MODERATE today.
With little new snow and a firm, solidly refrozen crust underneath, avalanches are unlikely and the avalanche danger is LOW.
Look out if you find more than a skiff of new snow, in which case you might be able to trigger small Wind Slab or Wet Loose avalanches.
If you encounter an error with our observation submission platform, please email your observations to mtavalanche@gmail.com
Bridger Bowl Ski Area is closed for the season, and uphill travel is allowed. Please give employees and machinery plenty of room as they work to clean up from the season. Backcountry conditions will develop as spring storms impact the range. There are no ski patrol services, avalanche mitigation or terrain closures as conditions evolve. Call 911 for any incidents requiring outside assistance.
Our last daily avalanche forecast will be Sunday, April 20th. We will issue updates on Mondays and Fridays through the end of April.