This is Mark Staples with the avalanche forecast for Thursday, March 6th, at 7:00 a.m. sponsored by Highline Partners and Gallatin County Sheriff Search and Rescue. This forecast does not apply to operating ski areas.
The sound of wind chimes on my front porch at 3am told me winter is back with a complex storm system overhead today. A deep trough of low pressure is moving over the western US today with a large band of moisture in eastern Idaho this morning trying to move north into Montana. Adding complexity, winds are spinning around from the east in much of our forecast area.
This morning it’s snowing in most areas. As of 6am, 2 inches accumulated near West Yellowstone and Island Park, an inch near Big Sky, and a trace at Bridger and near Cooke. Temperatures are mostly in the mid to upper teens F. Light winds are blowing from the E and NE. At the Bridger Ridge, east winds are averaging 30 mph gusting to 48 mph.
Today will be cloudy and snowy. Winds from the E and NE will increase through the day gusting in the 40s this afternoon. Snowfall amounts are tricky to forecast with east winds. Most areas will get a few inches. Mountains near West Yellowstone and Island Park are supposed to get 8-12 inches if moisture in Idaho is able to move north. My money is on Red Lodge where it was snowing hard at 4am and a foot of snow could easily stack up today.
The avalanche danger will be rising today with wind and snow, but there’s a lot of uncertainty with how much snow will fall. .
- Wind slab avalanches will be the main hazard today as winds from the E and NE increase by afternoon. These wind slabs will be widespread and easy to trigger. HEADS UP - Expect drifting in odd places because winds don’t typically blow from the east.
- Persistent slab avalanches 2-3 feet deep remain a threat on isolated slopes in the mountains near West Yellowstone (southern Madison and Gallatin Ranges, and Lionhead). This is a tricky problem and has surprised riders on slopes like one at Lionhead last Friday and Cabin Creek last Thursday.
- Storm slab avalanches in the new snow could become a problem this afternoon on all steep slopes if forecasted snow amounts of 8-12 inches pan out.
The avalanche danger will rise to CONSIDERABLE today on wind loaded slopes and MODERATE on non-wind loaded slopes. With the danger rising and multiple avalanche problems, the best plan today will be to step back mostly avoiding avalanche terrain and let the storm play out.
The avalanche danger today near Bozeman, Big Sky, and Cooke City will be rising as well mainly due to east winds. Watch out for places locally heavier snowfall amounts where the danger will be higher. These places could be in our normal forecast zones or more likely areas to the east.
- Wind slab avalanches will be the main concern today, and strong winds from the east will cause drifting in unusual places. Strong easterly winds had already developed in the Bridgers early this morning and should blow strong in all other places by this afternoon. I bet fresh wind slabs will be easy to trigger but shallow.
Don’t take today’s avalanche situation lightly. Weird weather (east winds) can cause weird avalanches, so I’d be stepping back today, generally avoiding avalanche terrain to see what this storm does regardless of how much snow falls. Today the avalanche danger is MODERATE.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Avalanche awareness focused on springtime avalanche conditions: Thursday, March 13 at the Bozeman REI from 6-7:30 p.m. The event is free but has limited space and requires registration HERE.
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.