Mar 11, 2014 @ 6:02 am

Avalanche Advisory March 11, 2014

The avalanche danger is CONSIDERABLE in the West Central Montana backcountry on slopes 30 degrees and steeper. Over the past two days; heavy, wet snow and rain have loaded steep slopes in the advisory area

Good Morning, this is Dudley Improta with the West Central Montana avalanche advisory for March 11, 2014. This danger rating does not apply to operating ski areas and expires at midnight tonight (March 11).

Weather and Snowpack Analysis

This morning, northwest mountain winds are blowing 10 to 16 mph and gusting into the 20’s. High elevation temperatures are in the twenties (F). New snow accumulations are from 5 to 7 inches in the Southern Swans, Southern Missions and Rattlesnakes; to 3 to 4 inches in the Central Bitterroot and Southern Bitterroot. The southern part of the advisory area is under a winter storm watch until 9am.

Wet snow has accumulated in the mountains over the last couple of days; rain levels have reached above 6000 feet. The quick shot of sun on Saturday was enough to leave a thin crust, except on the northerly aspects. Storm layers on cold snow from last week are gaining strength; but reports from the Central Bitterroots and the Rattlesnakes indicate weak snow within a foot of the surface.

Even with pit tests strengthening; there is enough new weight from the last two day’s rain and snow to keep us at CONSIDERABLE today. Last night’s snow came in with colder temperatures which is a good thing for future stability.

Another concern is cornice failure. We got a report of human triggered cornices in the Brushy Fork of Lolo on March 8 (photo). Cornices are large, and weighted by the last week’s heavy snow and rain at higher elevations. The sunshine predicted for this week may tip the scales and cause some failures.

Weather Forecast and Avalanche Outlook

Snow over the last week (where it didn’t rain) came in under relatively warm temperatures. This is the type of snow that should settle quickly. I do expect the chances for cornice failure to rise with the anticipated sunny days.

This afternoon, temperatures will keep cooling as high pressure builds over the area through the week. A slight disturbance on Thursday is not expected to produce much precipitation. Enjoy the high pressure if you can, because mountain snow and valley rain should move back in Friday.

Missoula County Search and Rescue 

Missoula County Search and Rescue responded to the devastating avalanche off Mt. Jumbo, assisting initial response from the Missoula Fire Department, on February 28. They then responded to lost skiers up Grant Creek near the Snowbowl Ski Area that same evening. Not only did they respond, more than 12 members worked at Mt. Jumbo; and when all were accounted for; went to Grant Creek to search for skiers who, unlike the victims of Mt. Jumbo, chose to participate in an activity with hazards.

Our local Search and Rescue deserves acknowledgement and thanks.

Cheers for Charity – Draught Works – 918 Toole Avenue – March 18 – 5pm

Missoulaavalanche is being sponsored at Draught Works on March 18 with “Cheers for Charity”. Come on down and have a pint. The event will help raise a few bucks for the West Central Montana Avalanche Center.

If you would like to send us snow observations; you can use our public observations form on the internet or send us a quick e-mail at  [email protected] .

Ski and ride safe; have a good week.

We will issue the next advisory on Friday, March 14, 2014.


This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but the information can help you make a more informed decision regarding travel in avalanche terrain for the next few days.

Our advisory area includes National Forest System lands in the Bitterroot Mountains from Lost Trail Pass north to Granite Pass, the Rattlesnake Mountains north of Missoula and the Southern Swan and Mission Mountains near Seeley Lake, MT. Avalanche information for the Lookout Pass/St. Regis Basin area is available from the Idaho Panhandle Avalanche Center.