22-23

Natural Cornice Collapse in Beehive Basin

Date
Activity
Skiing

Came across this very large cornice that appeared to have broken naturally sometime in the past 24 hours. Saw a few others that had broken recently throughout our tour, but none as large as this.

Region
Northern Madison
Location (from list)
Beehive Basin
Observer Name
Eric Heiman

Whumpf on wind drift at Lulu Pass

Lulu Pass
Cooke City
Code
Latitude
45.07090
Longitude
-109.95800
Notes

We rode to Round Lake, Goose Lake wilderness boundary and Lulu Pass. We saw a coulpe of small and very steep avalanches that released in the new snow. We dug 3 pits and got ECTX or ECTN28 on the new/old snow interface 2-3 feet under the surface. We were glad to not find propogation. Wind ramped up during the morning creating white-out conditions at time. At Lulu Pass we went to investigate wind slabs and got a collapse (whumf) when we stepped on it. Wind-loaded slopes are dangerous right now. Slopes ae actively loading and sensitive to triggering.

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

Wind drifted slopes are ready to slide

Date
Activity
Snowmobiling

We rode to Round Lake, Goose Lake wilderness boundary and Lulu Pass. We saw a coulpe of small and very steep avalanches that released in the new snow. We dug 3 pits and got ECTX or ECTN28 on the new/old snow interface 2-3 feet under the surface. We were glad to not find propogation. Wind ramped up during the morning creating white-out conditions at time. At Lulu Pass we went to investigate wind slabs and got a collapse (whumf) when we stepped on it. Wind-loaded slopes are dangerous right now. Slopes ae actively loading and sensitive to triggering.

Region
Cooke City
Location (from list)
Lulu Pass
Observer Name
Doug Chabot

GNFAC Avalanche Forecast for Fri Feb 24, 2023

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>All the mountain ranges have snow from the storm that ended on Tuesday. Today, winds will continue to get stronger and load slopes even more. East wind earlier in the week moved snow into unusual places and today's SW gusts will blow it around further. I expect newly formed wind-drifts to easily avalanche today. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The storm dropped 2-4 feet of snow, and for the most part, did not result in widespread avalanches. The exception is Cooke City where a few large avalanches ran with the storm or immediately after (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28255"><span><span><span><strong><span… and photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Given the large load of 4.5” </span></span></span></span></span></span><a href="http://snow.wyo.gov/snow-surveys/snow-water-equivalent-swe"><span><span… water equivalent</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, I was pleasantly surprised to not find widespread avalanche debris as I rode around north of town yesterday (</span></span></span></span></span></span><a href="https://youtu.be/0NbX8-TzV1w"><span><span><span><strong><span><u><span>…;).&nbsp; Throughout our forecast area, the storm’s avalanche activity was limited, which is a sign of a strengthening snowpack (videos: </span></span></span></span></span></span><a href="https://youtu.be/QSMoCGCfUXA"><span><span><span><strong><span><u><span>… Fork</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://youtu.be/dBHp08f7F6g"><span><span><span><strong><span><u><span>…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Get ready, because here comes the caveat to a “strengthening snowpack”: today’s fresh wind-drifts will either avalanche naturally or be easily triggered. Strong wind and loose snow are a hazardous combination. Drifting snow adds weight to a snowpack that only had minimal time to adjust to the last snowstorm. Shooting cracks in a wind drift is a sign of unstable and dangerous conditions; it is Mother Nature tapping your shoulder and disapprovingly wagging her finger. Slopes that are spared wind-loading might harbor weak layers at the interface below this week’s new snow that could avalanche. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is rated CONSIDERABLE on wind-loaded slopes since human-triggered avalanches are likely. On all other slopes the danger is rated MODERATE.</span></span></span></span></span></span></p>

<p><br />
<span><span><span><span><span><span>Please share avalanche, snowpack or weather observations via our</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>…; </span></span></span></span></span></span><span><span><span><strong><span><u><span><span>website</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, email (</span></span></span></span></span></span><span><span><span><strong><span><span>mtavalanche@gmail.com</span></span></strong></span></span></span><span><span><span><span><span><span>), phone (406-587-6984), or Instagram (#gnfacobs). </span></span></span></span></span></span><span><span><span><span><span><span>&nbsp;</span></span></span></span></span></span><span><span><span><span><span><span>&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The mountains received 6” of snow yesterday and the wind is blowing strong. I expect newly formed wind-drifts to easily avalanche today. Shooting cracks in a wind drift is a sign of unstable and dangerous conditions; it is Mother Nature tapping your shoulder and disapprovingly wagging her finger. Slopes that are spared wind-loading might harbor weak layers at the interface below this week’s new snow that could avalanche. </span></span></span></span></span></span></p>

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