GNFAC Avalanche Forecast for Thu Apr 1, 2021

Not the Current Forecast

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Thursday, April 1st at 7:00 a.m. Today’s forecast is sponsored by Cooke City Motorsports and Spark R&D. This forecast does not apply to operating ski areas.

Mountain Weather

This morning, skies are clear, mountain temperatures are in the high teens to mid 20s F, and wind is west to southwest at 10-15 mph with gusts of 25 mph. Under sunny skies temperatures are forecasted to hit the mid-40s in the southern ranges and mid-50s in the north and might not drop below freezing tonight. Wind will remain westerly and moderate. Tomorrow and Saturday will also be sunny and warm. I expect to hear my first lawnmower this weekend, and that’s no April Fool’s joke.

Snowpack and Avalanche Discussion

All Regions

Today is “Opening Day” for wet avalanches. The sun is intense and mountain temperatures are climbing well above freezing. As surface snow moistens it will begin to avalanche as loose, wet slides. These slides will be obvious and predictable and confined to the top few inches of the snowpack on slopes bathed in sun. Snow getting wet for the first time will be extra reactive which Ian discusses in his video from the northern Bridger Range yesterday. The slightest change in aspect and wind will affect snow surface temperature and rate of melting. Today, mid-mountain breezes could keep wet snow avalanches from becoming widespread, but even small wet slides can twist a knee or push us into a terrain trap (gully, cliff, trees, etc). Air temperatures are forecasted to be above freezing tonight which means wet avalanches will occur deeper and earlier in the day tomorrow. 

While wet avalanches are the #1 concern, we need to be mindful of others. Wind slabs at the ridgeline, cornices sagging, breaking and triggering slides, depth hoar at the ground, and perhaps a weak layer 2-feet under the surface. Although each one of these is unlikely to occur, when we travel in the backcountry our avalanche concern is not binary. Added together these concerns increase the odds of getting caught in a slide. Avoid slopes that are getting wet and stay clear of cornices, both on the ridgeline and on slopes below. In dry snow it’s a good idea to dig and test just to be safe and not get surprised. 

Today, because of the wide array of concerns, avalanches are possible and the danger is rated MODERATE on all slopes. If temperatures are warmer than forecasted or wind dies down, avalanche activity may become more widespread. Situational awareness is crucial because the snowpack is changing by the hour. 

If you get out, please send us your observations no matter how brief. You can submit them via our website, email (, phone (406-587-6984), or Instagram (#gnfacobs).

Upcoming Avalanche Education and Events

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:

April 5, 6:30 p.m., Forecaster Chat with Alex Marienthal, hosted by Uphill Pursuits, “Spring Snowpack and Forecasting Tools”. Link to Join.

The Last Word

This French video of a skier triggered avalanche, burial and rescue is unbelievable and worth 5 minutes of your time. Multiple GoPro cameras caught the action and you’ll watch a successful partner rescue unfold. The takeaway is simple: practice. There’s no shortcut to being a honed partner.

  <<    >>