20-21

GNFAC Avalanche Forecast for Fri Mar 19, 2021

Snowpack and Avalanche Discussion

<p>Today is a day of transition between the warm, dry conditions of the last two weeks and the unsettled weather that is setting in for the next week (<a href="https://www.youtube.com/watch?v=ZydqEm8GAMY"><strong><u>video outlining concerns with this transition</u></strong></a><strong>)</strong>.&nbsp;&nbsp;</p>

<p>Increasing clouds and strong winds will likely keep wet snow and wet avalanches in check today. Avalanches are unlikely while the snow surface is frozen. However, be wary if skies stay clear and sunny into the afternoon or it starts to rain.&nbsp;</p>

<p>A couple extra hours of sunshine would push the snowpack from crusty and refrozen to wet and gloppy with the possibility of wet slides. If the snow surface is wet more than a few inches deep on sunny slopes, move to shadier or lower angled slopes. There will probably only be a sprinkle of rain (if any), before precipitation switches over to snow this afternoon. But if it really starts to rain, the avalanche hazard will rapidly increase, particularly on shady slopes which have remained dry up to now.&nbsp;</p>

<p>With the snow surface expected to remain mostly frozen, avalanches are unlikely and the avalanche danger is LOW today. If it remains sunny into the mid-afternoon or rains, the avalanche danger will rise to MODERATE on slopes with wet snow.</p>

<p>Snow overnight will bring a whole different set of concerns tomorrow, so be sure to check the forecast tomorrow morning if you’re getting out this weekend.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>&nbsp;</p>

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:

TOMORROW! March 20, 5:30 p.m., Snowpack Update for Bozeman Splitfest, online Link to Join HERE

Fan

Date
Activity
Skiing

Today Henry and I skied the north east face of Fan mountain. Although it was a warm day, the wind help to prevent excessive warming up high on solar aspects. We dropped in and while skiing the upper pitch, my sluff triggered a small dry loose that entrained enough snow to call it a true D1. When skiing the second pitch, I was noticing the snow became much warmer and very wet. I did a ski cut across the gut and ran wet loose snow to the apron. We found the snow on this aspect and elevation to be thin with poor structure. Not nearly as confidence inspiring as our other observations on similar aspects at similar elevations.

Region
Northern Madison
Location (from list)
Fan Mountain
Observer Name
Tatum Whatford

Large Whumph in Specimen Creek

Specimen Creek
Southern Gallatin
Code
Latitude
45.03380
Longitude
-111.01700
Notes

From obs: "Our group noted a large collapse, including a very loud whoompf and shooting cracks while ascending the SW ridgeline of Meldrum Mountain at roughly 8,000ft. The snow here was between 40cm - 70cm and still had quite a weak, faceted layer underneath..."

Number of slides
0
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Red Flag
Advisory Year

Meldrum Mountain, Yellowstone NP

Date
Activity
Skiing

Our group noted a large collapse, including a very loud whoompf and shooting cracks while ascending the SW ridgeline of Meldrum Mountain at roughly 8,000ft.

The snow here was between 40cm - 70cm and still had quite a weak, faceted layer underneath.

After noting the thin, weak snow, we opted to stay on ridge-lines and ski lower angle terrain, and had excellent corn skiing.

Region
Southern Gallatin
Location (from list)
Specimen Creek
Observer Name
Matt Standal

GNFAC Avalanche Forecast for Thu Mar 18, 2021

Snowpack and Avalanche Discussion

<p>Wet avalanches are our main concern today. Yesterday's temperatures reached the 40s and sunny slopes moistened but held together. There were no widespread loose avalanches. On slopes that were shady the snowpack is still cold and wintry. Today will be a few degrees warmer, yet a breeze might provide enough cooling to keep avalanche activity in check. It will take a couple hours for the frozen surface to soften up and in general I expect small, wet loose avalanches on sunny slopes. The interplay of elevation, aspect and timing is critical because the snow surface and avalanche danger can change rapidly. Ian explains it further in his <a href="https://youtu.be/g8s9PZB134E"><strong><u>video</u></strong></a&gt; from Lionhead.&nbsp;</p>

<p>You don’t need a compass or watch to inform you where and when slopes become unstable, just pay attention. Sunny slopes will get wet and gloppy. The more intense the sun is, the wetter slopes will become. A sign that wet avalanche danger is rising is sinking past your ankles in wet snow or seeing large pinwheels of snow rolling downhill.&nbsp;</p>

<p>Dave was in Taylor Fork and Lightning Creek yesterday and had 3 things on his mind: wet avalanches, a potential new weak layer at the surface if it gets buried (near-surface facets), and also sugary depth hoar near the ground which broke in his test (<a href="https://youtu.be/3Adq_x3APAg"><strong><u>video</u></strong></a&gt;). The wet snow is the primary concern today, but the other two may become problems when it snows Friday night.&nbsp;</p>

<p>For today, the <strong>wet snow avalanche danger</strong> will start out LOW but rise to MODERATE on slopes that become wet and slushy.&nbsp;</p>

<p>The <strong>dry snow avalanche danger</strong> is rated LOW on all slopes because avalanches are unlikely.</p>

<p>The mountains outside Cooke City reached the low 40s yesterday. Today will be a few degrees warmer and sunny slopes will get moist and shed surface snow in wet loose avalanches. Wind is expected to keep the snow surface cool which will inhibit avalanches becoming widespread. On slopes not affected by the sun the snowpack is dry and mostly stable (<a href="https://youtu.be/VQd7lPN6zTQ"><strong><u>video of current conditions</u></strong></a> from Tuesday).</p>

<p>For today, the <strong>wet snow avalanche danger</strong> will start out LOW but rise to MODERATE on slopes that become wet.&nbsp;</p>

<p>The <strong>dry snow avalanche danger</strong> is rated LOW on all slopes because the snowpack lacks buried weak layers and avalanches are unlikely.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

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:

March 20, 5:30 p.m., Snowpack Update for Bozeman Splitfest, online Link to Join HERE