Logan Avalanche Advisory

Forecaster: Toby Weed


Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)

Danger Rose Tutorial

There is a Level 3 or Considerable danger on some slopes in the backcountry, and dangerous avalanche conditions exist in drifted upper elevation terrain... You'd probably trigger fresh wind slab avalanches 1 to 2 feet deep and/or large cornice falls if you travel on steep drifted slopes or venture too close to unstable cornice lips. Dangerous and destructive deep slab avalanches are possible on drifted upper elevation slopes, especially on slopes with poor snow structure and those overrun by wind slab or cornice fall avalanches. You'll find safer conditions at lower elevations, on lower angled slopes, and in sheltered terrain. Careful snowpack evaluation, cautious route finding, and conservative decision making are essential in avalanche terrain today.


While dangerous avalanche conditions exist on some drifted upper elevation slopes, there are many areas with fairly stable snow and good powder riding... You'll find a few inches of new snow on a sun-crust at lower elevations. The Tony Grove Snotel at 8400' reports 3 or 4 new inches snow with 4/10ths of an inch of water from yesterday...It's 24 degrees this morning and there is 129 inches of total snow with 143% of average water content for the date. South and southwest winds picked up again overnight, with Mount Ogden reporting several hours with 40 mph averages and gusts in the 60s...


Locally, riders this week observed evidence of large fresh natural deep slab avalanches off Millville and Providence Peaks in Providence Canyon and Cornice Ridge and Castle Rock in the Tony Grove Area... It appears that these were triggered by cornice fall or overrunning wind slab avalanches, and they all occurred sometime in the morning on Tuesday (3-22-11).. This was during a period of particularly heavy snowfall and strong winds.... I was able to get up to the Millville Peak and Castle Rock Avalanches... Both are classified as hard slab avalanches, and they both failed on very thin persistent weak layers. But, the failing layers were different, with the 3-4' deep, 150' wide Millville Peak slab failing on a thin layer of frost or surface hoar, and the 6-10' deep, 500' wide Castle Rock hard slab failing on small sugary facets. I also received a first-hand report of an unintentional snowmobile triggered avalanche from Wednesday (3-23-11) at mid elevations on the north side of Providence Canyon... Apparently not as big as the naturals, but it was a surprise to the riders involved because of the unexpected location.... I failed to get all the details....

.See our avalanche list HERE


      Over the next 24 hours.

Avoid fresh wind slabs on steep slopes in lee terrain and deceleration zones or deposition areas... Substantial accumulations and sustained strong south southwest winds have created dangerous avalanche conditions in drifted terrain... Triggered wind slab avalanches 1 to 2 feet deep are probable on steep drifted slopes, especially in upper elevation terrain...


      Over the next 24 hours.

Dangerous deep slab and shallower persistent slab avalanches involving old snow are possible, and most likely on slopes facing the northern quadrant of the compass. The significant load of new snow from Monday and Tuesday is apparently enough to reactivate deeply buried, mid-winter weak layers in some areas... Today's load of drifted new snow won't help matters on slopes that are already close to the critical balance.... Deep slab avalanches will probably need a fairly large trigger like overrunning cornice falls or wind slab avalanches. But if you trigger one, watch out, because it could certainly pack a destructive and potentially deadly punch...


      Over the next 24 hours.

Continue to avoid and stay out from under the huge overhanging cornices on the major ridge lines, which often break further back than expected and could trigger dangerous avalanches on steep slopes below.


Looks like the moist weather pattern will continue through the weekend, with a good chance for more accumulating snow Today, tomorrow, and again Sunday... 5 to 9 inches are forecast for today with sustained southwest winds again.... Expect a bit of clearing later this evening, with lingering snow and another 2 to 4 inches possible overnight. Yet another wave of Pacific storminess will bring more snowfall tomorrow evening into Sunday...


You can view a photo summary of last year's avalanche activity in the Logan Area HERE

Join the friends of the Utah Avalanche Center in Logan on facebook. Click HERE

I will update this advisory in the mornings on Mondays, Wednesdays, Fridays, and Saturdays, and on other days if backcountry avalanche conditions warrant...

You have the opportunity to participate in the creation of our own community avalanche advisory by submitting avalanche and snow observations. You can also call us at 801-524-5304 or Toby at 435-757-7578, or email by clicking HERE

Donate to your favorite non-profit – The Friends of the Utah Avalanche Center. The UAC depends on contributions from users like you to support our work.

This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.

This information does not apply to developed ski areas or highways where avalanche control is normally done.  This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.

This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.