19-20

Many naturals near Flathead Pass

Flathead Pass
Bridger Range
Code
HS-N-R3-D2.5-O
Elevation
8000
Aspect
NE
Latitude
45.96840
Longitude
-111.02100
Notes

We drove to Flathead Pass to look for avalanches from the recent storm and saw widespread crowns that were fresh enough to have ran during the end of the storm. A couple broke in the 3 feet of storm snow, b ut many were 3-5' deep on persistent weak layers.

Number of slides
10
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Naturals near Flathead Pass

Flathead Pass
Bridger Range
Code
HS-N-R3-D2.5-O
Elevation
8000
Aspect
NE
Latitude
45.96840
Longitude
-111.02100
Notes

Natural avalanche crowns were seen on 2/20/2020 near Flathead Pass that appear to be from the last 2-3 days. They were fresher than crowns that were seen here on 2/9, and these slopes had not slid when the area was visited on 2/9.

Number of slides
3
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
48.0 inches
Vertical Fall
700ft
Slab Width
500.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

GNFAC Avalanche Forecast for Thu Feb 20, 2020

Snowpack and Avalanche Discussion

<p> With blue skies, light winds, and plenty of soft snow left to find, it’s going to be a very pleasant day in the mountains and it would be easy to get lulled into a sense of complacency. But don’t forget that we’re just on the tail end of an intense and long lasting avalanche cycle. Yesterday was only the second day in the whole month of February that we didn’t get a report of a new avalanche <a> (</a><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><strong>avalanche log</strong></a>). Without new snow, the snowpack will slowly adjust and stabilize but we’re not quite there yet. &nbsp;</p>

<p>Since Monday, a snowmobiler triggered an avalanche near Cooke City that broke 3-4’ deep and 100’ wide across a small slope (<a href="https://www.mtavalanche.com/node/22142"><strong>photo and details</strong></a>), a rider triggered a large avalanche more than four feet deep that failed on weak snow near the ground on Buck Ridge (<a href="https://www.mtavalanche.com/node/22129"><strong>details</strong></a&gt;), and several large natural avalanches broke on heavily wind loaded slopes on Wilson Peak near Big Sky (<a href="https://www.mtavalanche.com/images/20/natural-avalanches-wilson"><stron…;). Recent avalanche activity is a clear sign that avalanches remain possible. The weak layers near the ground need more of a break from loading before we can trust them. Conservative terrain choices remain prudent.</p>

<p>With sunny skies and temperatures rising to near freezing, we also need to start thinking about wet snow avalanches. I don’t expect a big hazard, but be on alert if the snow surface gets wet and you see rollerballs or pinwheels.</p>

<p>The avalanche danger is rated MODERATE.&nbsp;</p>

<p>Avalanches are unlikely in the mountains around West Yellowstone. Yesterday, Doug and I were on Skyline Ridge and had great visibility. We could see across much of the southern mountains and saw plenty of tracks on steep slopes, but didn’t see any recent avalanches (<strong><a href="https://www.youtube.com/watch?v=2IzNvRo0R3w&amp;list=PLXu5151nmAvSbcbVf…;). This fits with what we’ve seen near Lionhead (<strong><a href="https://www.youtube.com/watch?v=S_gUqe5axGQ&amp;feature=youtu.be">video…;). The last reported slide in the southern Madison Range was on Saturday in Taylor Fork (<strong><a href="https://www.mtavalanche.com/node/22074">details</a></strong&gt;) and it’s been a month since the last large slide was reported near Lionhead (<strong><a href="https://www.mtavalanche.com/node/21706">details</a></strong&gt;). The weak snow at the ground is still there, but you’d have to get very unlucky to trigger an avalanche. Cover your bases by riding one at a time on steep slopes and watching your partners from a safe spot that is out of the runout zone. The avalanche danger is LOW.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an&nbsp;<strong><a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank">observation form</a></strong>, email us (<strong><a href="mailto:mtavalanche@gmail.com&quot; target="_blank">mtavalanche@gmail.com</a></strong>), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.

COOKE CITY

Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.

BOZEMAN