Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Sunday - March 2, 2014 - 6:55am
bottom line

There is a HIGH or Level 4 danger on drifted slopes in the backcountry. Dangerous deep slab avalanches, failing on weak persistent faceted layers near the bottom of the snowpack are possible and might be remotely triggered from a distance or even from the flats below. Triggered wind slab avalanches and large cornice falls are likely at upper elevations, and entraining wet sluffs will become likely at mid and lower elevations if the sun peeks out and temperatures warm. Avoid travel in avalanche terrain today. Stay off of and out from under steep slopes and obvious or historic avalanche paths.

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avalanche warning

THIS AVALANCHE WARNING IS FOR THE LOGAN AREA MOUNTAINS OF NORTHERN UTAH AND THE MOUNTAINS OF EXTREME SOUTHEAST IDAHO. STRONG WINDS AND HEAVY SNOWFALL HAVE CREATED A HIGH AVALANCHE DANGER.   BACKCOUNTRY TRAVELERS SHOULD STAY ON SLOPES LESS STEEP THAN 30 DEGREES AND AVOID AVALANCHE RUNOUT ZONES. THIS WARNING DOES NOT INCLUDE SKI AREAS OR HIGHWAYS WHERE AVALANCHE CONTROL IS NORMALLY DONE.
current conditions

There is now more than ten feet of total snow at the 8400' Tony Grove Snotel. Well over two feet of heavy new snow fell yesterday, with 3.6 inches of water in the last 24 hrs and 4.2" in the last 48. It's 27 degrees this morning, and there's 125 inches of total snow, containing 133% of average water content for the date. The 9700' CSI Logan Peak weather station reports 21 degrees and a rimed wind sensor. Southwest winds at other mountain sites diminished significantly overnight after sustaining ground baring strength for much of the day yesterday.
recent activity
  • Skiers intentionally triggered a large deep slab avalanche on a small test slope in Franklin Basin yesterday 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.
  • Numerous triggered and natural wind slab and storm snow avalanches were reported from across the northern Utah mountains in the past couple days. Natural wind slab and cornice fall activity at upper elevations was observed locally with clearing on Friday.
  • It was very easy to trigger entraining wet sluffs Friday on test slopes at mid-elevations in Providence Canyon, and with more fresh snow, and if the sun peeks out for a while and warms things up, resulting heavy debris piles could get pretty big on longer slopes.

Unexpectedly large intentionally triggered avalanche on a small test slope in Franklin Basin, 3-1-2014. (Brodhead)

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

Looks like the rapid accumulation of 3.6" of water weight and significant drifting yesterday was enough to reactivate the dormant deeply buried persistent weak layers. Dangerous deep slab avalanches failing on faceted weak layers near the bottom of the snowpack are likely today, especially on drifted upper and mid elevation slopes. Be especially cautious in shallow, rocky or previously wind scoured terrain. Deep slab avalanches might be triggered remotely, from a distance or below. Pay attention to potential red flags, especially whumpfing or audible collapses, and stay off of and out from under steep slopes and slopes than are connected to steep slopes. (steeper than about 30 degrees)
Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Triggered wind slab avalanches, 2 to 3-feet-deep and large cornice-falls are likely in drifted 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. 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.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 12 hours
description

Loose Wet Avalanches, entraining significant piles of saturated fresh snow are likely in steep mid and lower elevation terrain. Avoid and stay out from under steep slopes with saturated snow and be especially careful above trees, benches or other terrain traps that you could be dragged into.

Easily triggered wet sluffs on mid-elevation test slopes in Providence Canyon. VIDEO
weather

Snow showers are likely and continuing this morning, with a high temperature at 8500' forecast at 33 degrees and moderate west-southwest winds today. Solar warming and greenhousing could be an issue this afternoon if the sun peeks from behind cloud cover. 2 to 4 inches of accumulation is likely tonight, with low temperatures around 24 degrees. Unsettled and showery weather will continue through the middle of the coming work week. Expect a brief break on Wednesday and the next Pacific storm on around Thursday.

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.

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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.