Avalanche Advisory February 14, 2014

On slopes above 5000 feet, which are 35 degrees and steeper, the avalanche danger is CONSIDERABLE in the West Central Montana backcountry. Recent storms and high winds have loaded steep slopes across the area.

Good Morning, this is Dudley Improta with the West Central Montana avalanche advisory for February 14, 2014. This danger rating does not apply to operating ski areas and expires at midnight tonight (Feb. 14).

Weather and Snowpack Analysis

This morning mountain winds, out of the south/southeast to south/southwest, are blowing from 6 to 16 mph and gusting to 20 mph. High elevation temperatures are hovering in the low twenties (F). The area received anywhere from 4 to 8 inches of snow over the last two days, with the central Bitterroot picking up the most precipitation. We are currently under a winter weather advisory.

The big storms predicted for Wednesday and yesterday failed to produce as prophesied. Rain up to 6000 feet caused a “Valentine’s Day Massacre” of our low elevation snowpack. However, sustained high winds, at times gusting 60mph, provided plenty of action.

The winds have moved snow over the last couple of days. The Snowbowl Patrol was able to trigger wind slabs, up to 15 inches deep, by ski-cutting on Tuesday and by bombing on Wednesday. Also on Wednesday, Yurtski guides (Southern Swans) reported high winds; the sled tracks, they punched into the yurts, were obliterated in 2 hours.

Travis and I toured the ridges near Lolo pass (snow profile) yesterday; we had high winds (video) (photo) and initiated shooting cracks while traveling on leeward slopes (photo). Tim and Dave reported the same deal in the Rattlesnakes; shooting cracks, collapsing; wind slabs being the number one concern. Casey Worth and Geoff Fast agreed on the CONSIDERABLE call near Lost Trail; noting the possibility of big sluffs as well as the potential for wind slabs above 7000 feet.

Deeper instabilities reacted in the pits from Lost Trail Pass (snow profile) and the Rattlesnake (snow profile). This adds the possibility of “stepping down” (producing a larger slide if the new snow or a wind slab is triggered).

Basic avalanche 101 – I would be suspect of possible wind slabs (leeward terrain) or the failure of new storm snow on slopes steeper than 35 degrees. It would be no surprise if you triggered a slide in these conditions.

Weather Forecast and Avalanche Outlook

Today and into the evening, a storm should deliver more snow and wind. After a brief respite, another system is predicted to move in Saturday and Saturday night. This second wave may produce higher snow amounts and stronger winds.

At this point; I would expect avalanche conditions to remain similar.

It’s a good weekend to “be on your game” if considering riding or skiing steep slopes. Choose appropriate terrain (ex. look for wind-loading) and appropriate methods (one at a time, have a backup plan, etc.).

Last Chance for a Level 1

The last Missoulaavalanche Level 1 may have to be canceled if we don’t get some more sign-ups. If you’ve been waffling – sign up now.

Thanks!

Missoula Arctic Cat (Harley-Davidson) sponsored an avalanche awareness program this last Wednesday. We met some great folks. We appreciate these guys from Arctic Cat hooking us up with local riders. If you’re interested in a program at your shop contact us at [email protected].

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 great holiday.

Steve will issue the next advisory on Tuesday, February 18.