GNFAC Avalanche Forecast for Thu Mar 12, 2015

Not the Current Forecast

Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, March 12, at 7:30 a.m. Alpine Orthopedics and Javaman sponsor today’s advisory. This advisory does not apply to operating ski areas.

Mountain Weather

This morning Big Sky and Cooke City received an inch of snow. Other places may have been dusted. Temperatures were in the high 20s and low 30s F, and winds were blowing 15-20 mph from the WSW. Don’t get your hopes up for snowfall today. An inch of snow may fall at most. Otherwise, clouds will linger over the area and give way to more sunshine for Friday. Today temperatures should climb into the 40s F with winds blowing 10-15 mph from the WNW. Long term weather forecasts are not too reliable, but we’re desperate. Weather models are showing a decent chance for snow starting Sunday night. We’ll see.

Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range   

Lionhead Area near West Yellowstone   Cooke City

There isn’t much to say about the avalanche danger today, and this morning’s trace of new snow will not change the situation. With a strong and stable snowpack, dry snow avalanches are unlikely (video). With cloudy skies today, wet snow avalanches are unlikely as well. For these reasons, the avalanche danger is rated LOW on all slopes.

Looking ahead - If the weather models are correct, we could get a decent shot of snow Sunday night and possibly more this time next week. The last two weeks of high pressure changed the shape of snow crystals at the snow surface into faceted grains that do not bond well. Any snow that feels like loose powder is actually these faceted crystals. Doug and I found them in Teepee Basin in the southern Madison Range on Tuesday mostly on shaded, north aspects. This faceted snow could become the next weak layer and cause avalanches when we get more snow and build a slab on top of it.

I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.

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