GNFAC Avalanche Forecast for Fri Apr 4, 2025
This is Ian Hoyer with the avalanche forecast on Friday, April 4th, at 7:00 a.m. sponsored by Polaris and Montana State Parks. This forecast does not apply to operating ski areas.
New snow totals since yesterday morning are:
5-7” around Bozeman and Big Sky.
0-1” everywhere else
Temperatures this morning are in the teens F. Winds are light out of the north and northwest. Except in the Bridger Range, where they’re a little stronger and out of the east.
Snow showers in the north will end this morning, with skies gradually clearing across the whole area by this evening. High temperatures will be in the 20s and 30s F. Wind speeds will pick up a bit this morning, generally blowing from the north.
Expect dry, sunny and warmer conditions through the weekend.
All Regions
Today’s transition between colder, snowy weather and warm, sunny, springlike weather bring a range of concerns.
While winds have generally been light, Wind Slab avalanches are a concern in places where winds have drifted and slightly stiffened the recent snow. Look for these drifts below cornices and near ridgelines. With east winds in the Bridger Range, there may be drifts in some unusual locations, so be particularly watchful there. Over the last couple days, thin, relatively small, wind slabs have been reported in the Bridger Range, Beehive Basin, and the mountains around Cooke City. Looking for wind textured surfaces and avoiding drifts is the easiest way to deal with this problem.
Dry loose avalanches (sluffs) can pack a surprising punch and there is plenty of soft snow for them to entrain. Don’t underestimate their power if you’re getting onto steeper slopes.
As soon as direct sunshine hits slopes today wet loose avalanches will become the big player. Today will be the first time the recent snow gets wet. This initial wetting is often the peak of instability for wet loose avalanches. With lots of recent snow, these could be quite big slides and they’ll run a long way on last week’s crusts.
Temperatures are warmer and it’s going to be sunnier around West Yellowstone, Island Park, and Cooke City this morning, so the onset of these wet loose slides will be earlier in those places. Near Bozeman and Big Sky, there is more new snow but temperatures are cooler and clouds should stick around for longer, so it’ll take longer for things to get going, but once they do, we could see bigger avalanches.
Be on alert as soon as the sun is not blocked by clouds. The snow surface getting sticky and wet and rollerballs rolling down hill are your clues that it’s time to move to shadier or less steep slopes.
With a range of concerns to watch for and large avalanches possible, the avalanche danger is MODERATE today.
Hyalite Road Closure
The Hyalite Canyon Road is closed to ALL MOTORIZED VEHICLES until the morning of May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed. Contact the Bozeman FS Ranger District for more info.