MONDAY, MARCH 23

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued 
on Monday, March 23rd, at 7:30 a.m. This advisory does not apply to operating ski areas.

MOUNTAIN WEATHER

Before Saturday night’s storm departed another one to two inches of snow fell yesterday morning 
above 8,000 feet. A cold front moved in last night dipping temperatures into the teens and dropping 
five inches in the Big Sky area and one to two inches everywhere else. It’s still snowing lightly 
and will continue this morning. Winds are out of the northwest at 15-20 mph. In the next 24 hours 
I’m expecting another two to three inches of snow with winds shifting to the west at 10-15 mph and 
temperatures reaching the mid 30s. This week looks colder than average with small shots of snow 
rolling through. My fingers are crossed we won’t have to mention the word “rain” again this season.

SNOWPACK AND AVALANCHE DISCUSSION

The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains 
around Cooke City and the Washburn Range:

You don’t need to be sitting in front of your TV to experience March Madness, just step outside. 
The weather has been manic lately: pouring rain yesterday morning, snow falling today. The snowpack 
doesn’t like rapid change. Warm, above freezing temperatures last week and this weekend was a 
factor in a few avalanches. Yesterday we investigated slides on the west side of the Bridger Range. 
It looks as though wet snow rolled downhill and triggered slab avalanches that were only 100 feet 
wide, but ran close to 1000 feet vertical. The slides failed on faceted snow one to two feet off 
the ground. This is the same layer that fractured and injured a skier on the west side of Saddle 
Peak last Wednesday.

At elevations below 8,000 feet warm temperatures and yesterday’s rain severely weakened the 
snowpack. Cold temperatures will start to refreeze these layers, but it’ll take days, especially 
with the recent snowfall acting as insulation. If the snow is unsupportable and you sink to the 
ground, be extra careful about triggering slides. Yesterday, one of our regular observers took a 
quick tour into Beehive Basin. He could not isolate a column in his stability tests—a sign that 
the snowpack got weaker and is unstable. On Saturday, Mark investigated an avalanche in Sunlight 
Basin in Taylor Fork, the second slide in this area in a week. It also avalanched on faceted snow 
that got buried in mid February.

We’ve gotten reports of avalanches almost every day over the last week. They are not aspect 
dependent. Many slopes are stable and do not have substantial weak layers plaguing them, but some 
do. Do not assume that tracks on a slope mean adjacent terrain is safe and stable. It’s easy to be 
fooled. 

In the last 24 hours the snowpack has gotten unusual stresses with rain, warm temperatures, even 
a bit of sun and then freezing temperatures and now snow. Because of this, my confidence level that 
the snowpack is going to behave in a normal fashion is a bit shaken. Unusual weather brings unusual 
avalanches. I don’t anticipate this pattern to continue, but be extra cautious if you head out 
today. I’m rating the avalanche danger CONSIDERABLE across our entire advisory area.