Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Thursday - March 6, 2014 - 7:24am
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Heightened avalanche conditions exist and there is a MODERATE or Level 2 danger on many steep slopes in the Logan Area backcountry. More dangerous conditions, and a level 3 or CONSIDERABLE danger exist in some areas. Large cornice falls and triggered wind slab avalanches are likely in drifted upper elevation terrain, while wet avalanches are possible on saturated lower slopes. Dangerous deep slab avalanches are possible in some outlying, shallow, rocky areas with melt-softened snow or recent wind deposits. Evaluate the snow and terrain carefully, and continue to use safe backcountry travel protocols.

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current conditions

It's 35 degrees this morning, and the Tony Grove Snotel at 8400' reports 119 inches of total snow, containing 137% of average water content for the date. . The 9700' CSI Logan Peak weather station reports 30 degrees and 30 mph average wind speeds from the south southwest. You'll find weak surface crusts and generally saturated snow conditions at lower elevations and on many higher sunny slopes, with heavy powder conditions now limited to sheltered upper and mid elevation terrain. South winds picked up significantly overnight, so at upper elevations we should expect to find sastrugi and scoured areas on exposed windward slopes, with cornice build-up and stiffer wind-deposited snow in lee terrain.

Southwest winds started to increase yesterday afternoon, and I could see drifting up high off the Wellsville Crest. 3-5-2014


recent activity
  • Skiers intentionally triggered a large deep slab avalanche on a small test slope in Franklin Basin Saturday afternoon. The avalanche on a northeast facing slope at around 8100' in elevation was reported to be 3 feet deep and about 250' wide. It failed in old snow on a deeply buried persistent weak layer consisting of sugary faceted snow. Report HERE
  • Numerous natural avalanches ran in the Logan Zone during last weekend's windy and very wet storm. Most were fairly small, and the evidence was mostly buried by the continuation of the storm. But, I noticed evidence of a large deep slab avalanche, most likely from Saturday, in the Coldwater Canyon Area in the Wellsville Mountain Wilderness above Mendon. Mostly filled-in crowns from this very broad avalanche on an east facing slope at around 8700' in elevation are visible from Cache Valley.
  • Tuesday at upper elevations in the Mount Naomi Wilderness, backcountry skiers intentionally triggered a few shallow wind slabs with cornice drops, up to around a foot deep.

Evidence of some recent natural deep slab avalanche activity on the east side of the Wellsvilles above Mendon. 3-5-2014
Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Avoid and stay out from under large and overhanging cornices along major ridge-lines, which are likely to break further back than you expect and might trigger avalanches on drifted slopes below. Large cornice-falls and triggered wind slab avalanches are likely in drifted upper elevation terrain today. Watch for and avoid stiffer drifted snow or potential wind slabs on the lee sides of major ridge lines and in and around terrain features like rock outcroppings, sub-ridges and gullies.

Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 10 hours
description

Loose Wet Avalanches, entraining significant piles of wet snow are likely on steep sun warmed or rain saturated slopes and in lower elevation terrain where the snow is now quite wet. Avoid and stay out from under steep slopes with saturated snow during the heat of midday and be especially careful above trees, benches, or other terrain traps that you could be dragged into. Rain on the already saturated snow will increase the danger of wet avalanches.

Easily triggered wet sluffs on mid-elevation test slopes in Providence Canyon. VIDEO
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

The widespread weak faceted snow from the first half of the season snow appears dormant, for the most part and is so deeply buried and bridged now at upper elevations in the Central Bear River Range that It would be difficult for us to trigger a deep slab avalanche. Dangerous deep slab avalanches failing on faceted weak layers near the bottom of the snowpack are still possible in outlying shallow, rocky, or previously wind-scoured terrain that is now drifted or sun-warmed. The intentionally triggered deep slab on a small test slope in Franklin Basin and the large natural deep slab in shallower Wellsville Mountain terrain, which occurred on Saturday 3-1-2014 illustrate the potential.

weather

Snow is likely up high, mainly in the afternoon with a chance of thunder, 2 to 4 inches of accumulation is possible at upper elevations, with rain low. Expect fairly strong west winds and very mild temperatures, (high of around 40 degrees at 9000'). Expect showery weather tomorrow, becoming sunny in the afternoon. Not much is expected in the way of accumulation, and it'll be several degrees cooler. Looks like warmth and sunshine will return for the weekend, and unsettled, moist weather will continue next week.

Check out our one-stop weather page........HERE
general announcements

Campsaver and The Utah Avalanche Center in Logan are teaming up to give away a avalanche rescue kit - beacon, shovel and probe!
That's almost $400 worth of essential backcountry gear!  The more you share and like, the more chances you have of winning. Winner will be drawn at random early next week. Link is HERE

Show Us You Know the Snow: US & Canadian avy groups have a challenge to sidecountry riders: Use your camera to tell a short video story about how your crew gets ready to safely ride beyond the resort boundary. Videos will be posted & promoted by GoPro & other partners. The contest will run till Mar 21. The winner will be determined by a combination of most views & an expert panel. Prizes include: 2 days at Monashee Powder Snowcats, 2 4-day Gold Passes to any US resort, a Backcountry Access Float 22 airbag, gear from Backcountry.com, editing help and support from Sherpas Cinema, & more. Winners will be announced in late March. . Details at knowthesnow.com     Please share this with your friends

A video look at a HUGE natural avalanche in the Wellsville Range, from 2-19-2014...........HERE

Check out "Beaver Backside is the Backcountry," an Avalanche observation video from 2-16-2014 .....HERE   

A child's perspective on last week's natural wet avalanche above Zanavoo in Logan Canyon filmed on 2-17-2014 .......HERE 

Discount lift tickets are available at Backcountry.com - Thanks to Ski Utah and the Utah Resorts, including Beaver Mountain. All proceeds go towards paying for Utah Avalanche Center avalanche and mountain weather advisories.

Utah Avalanche Center mobile app - Get your advisory on your iPhone along with great navigation and rescue tools.

Remember your information can save lives. If you see anything we should know about, please participate in the creation of our own community avalanche advisory by submitting snow and avalanche conditions. You can also call us at 801-524-5304 or 800-662-4140, email by clicking HERE, or include #utavy in your tweet or Instagram.

Follow us at UAClogan on Twitter 

I'll issue these advisories on Monday, Wednesday, Friday, and Saturday mornings. 

This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist.