GNFAC Avalanche Forecast for Thu Mar 27, 2025
This is Mark Staples with the avalanche forecast on Thursday, March 27th, at 7:00 a.m., sponsored by Cooke City Super 8/Bearclaw Bob’s and the Idaho State Snowmobile Association - Avalanche Fund. This forecast does not apply to operating ski areas.
Enjoy the warmth and sunshine for one more morning as the weather pattern will turn back to winter tonight. The jet stream will generally stay to the south of us with cold air and multiple disturbances passing through for the next week or two. By this time next week there could be a decent amount of fresh snow in the mountains.
This morning air temperatures are in the mid to upper 30s F, about 4-5 degrees warmer than yesterday morning. Clear skies have likely cooled the snowpack on open slopes enough to refreeze and form a thin ice crust except on slopes in thick trees. Winds this morning are averaging about 15 mph and gusting up to 34 mph from the SW (a bit lighter in the Bridgers).
Today will kick off warm and sunny with rapidly warming temperatures reaching the low 40s F. Cloudy skies this afternoon and winds blowing 15-20 mph should put the brakes on warming. By the end of the day a few raindrops or snowflakes could fall as well as a rumble or two of thunder.
All Regions
Wet loose avalanches are the main concern today. Ian describes it well in his observation from yesterday in the northern Bridgers with aspect, elevation, and timing the three variables to consider. With above freezing air temperatures overnight, the snowpack will only have a superficial refreeze from clear skies. As soon as the surface crust melts, wet sluffs will be possible.
Pay attention to what’s above you. One of the main threats of wet loose avalanches isn’t triggering one, but having one start naturally above you, often near exposed rocks. Another significant concern are large CORNICES which are more likely to break spontaneously during rapid warm-ups.
Today, I’d only consider riding sunny slopes (east, south, and west) this morning just as they begin to warm and soften. I’d mostly be aiming for upper elevation north facing slopes that still have dry snow. Old wind slabs should mostly be stabilized, but the threat never goes away completely.
In the Lionhead area, southern Gallatin and Madison Ranges, and mountains near Cooke City to a lesser extent, there is a slight chance of triggering a persistent slab avalanche. I’d investigate the snowpack about 3 feet deep especially if going into more extreme terrain where the margin for error is narrow. A slide spotted three days ago on the Fin above Cooke City is a good example of this problem.
The avalanche danger today is MODERATE with wet avalanches an issue on slopes receiving direct sunshine at all elevations and shady slopes below treeline where the snowpack is mostly wet.
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