This is Ian Hoyer with the avalanche forecast for Friday, January 3rd, at 7:00 a.m. sponsored by Highmark Rentals and MTNTK Performance. This forecast does not apply to operating ski areas.
An AVALANCHE WARNING has been issued for the mountains around Cooke City. Heavy snowfall is overloading pre-existing weaknesses in the snowpack and creating very dangerous avalanche conditions. Human-triggered and natural avalanches are likely. Avoid avalanche terrain and avalanche runout zones. The avalanche danger is HIGH on all slopes.
This warning will expire or be updated by 6:00 a.m. on Saturday, January 4th, 2025.
In the last 24 hours, it has snowed:
10” (1.0” Snow Water Equivalent) in Cooke City
3-5” (0.4-0.6” SWE) near Big Sky, West Yellowstone, Island Park
2” (0.2” SWE) in Hyalite
Temperatures rose overnight in many areas and are in the mid-high 20s F this morning. Winds are 20-25 mph out of the southwest and west (a bit lighter in the Bridgers), with gusts of 30-40 mph.
Snowfall may be intense at times this morning, tapering off this afternoon before another round of snow hits tomorrow. By tomorrow morning, expect 6-8” of new snow near Cooke City, 4-6” near West Yellowstone, Island Park and Big Sky, and 3-5” around Bozeman. Winds will remain moderate and westerly. High temperatures will rise to near freezing in many areas.
Avalanche Warning
Heavy snowfall overnight and continued heavy snowfall today mean that natural and human triggered avalanches are both likely. Avalanches may break within the new snow or on the weak layers buried 2-4 ft deep (deeper in windloaded areas). Warming temperatures overnight mean the new snow is falling “upside down” (denser over less dense), which makes Storm Slab avalanches within the new snow especially likely. Avalanches will be bigger and even easier to trigger on windloaded slopes.
Persistent Slab avalanches breaking deeper in the snowpack on the early December weak layers are the wild card that really worry me today. During the last round of snow, there were big natural avalanches on Henderson Mountain and Sunset Peak. With rapid loading of the weak layers, I expect more of these big slides today.
Be very cautious if you get out today. Stay off and out from under all steep slopes. Low visibility will make it hard to tell how close you’re getting, so give yourself a wide margin.
The avalanche danger is HIGH on all slopes.
Steady snowfall over the last ten days has kept the snowpack teetering on the edge. It’s snowing again and you could easily trigger a large Persistent Slab avalanche on weak layers buried 1-3 ft deep (and deeper in windloaded areas). We continue to get feedback from the snowpack via collapsing, whumpfs, and avalanches (Check out our observations page to view the latest reports with all these red flags). New snow today will make these easier to trigger.
Winds have generally been light since snowfall began, so there is still plenty of soft snow available to blow around. Yesterday, the Big Sky Ski Patrol found sensitive wind slabs after the winds picked up just a little bit. Be on the lookout for fresh wind drifts where you could trigger a Wind Slab avalanche today.
Decision making should be pretty simple today - it’s snowing, weak layers are getting loaded, and avalanche conditions are dangerous. There is powder everywhere, so go out and enjoy it on slopes less than 30 degrees steep. The steep slopes will still be there when it stops snowing and conditions stabilize.
The avalanche danger is CONSIDERABLE today.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Wednesday, January 8, 2025, 7-9:30 p.m., Avy Savvy Night at the Colonial Theater, Idaho Falls. More information HERE.
We offer Avalanche Fundamentals with Field Session courses targeted towards non-motorized travelers VERY SOON in January and one geared towards motorized users. Sign up early before they fill up.
Every weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.
THANK YOU - Fall fundraiser
On behalf of the Friends of the Avalanche Center, we would like to extend our heartfelt thanks for your generous support of the Powder Blast fundraiser. This is our largest fundraiser of the year. We are thrilled to share that, thanks to your contributions and the incredible generosity of an anonymous donor, we have successfully met our fall fundraising goal.
There were two recent avalanche deaths in Utah involving solo travelers. One on Saturday but recovered on Tuesday (initial report), and a splitboarder traveling solo on Tuesday (initial report). Traveling alone in avalanche terrain carries significant additional risks.