Logan Avalanche Advisory

Forecaster: Toby Weed

BOTTOM LINE

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


Danger Rose Tutorial

Very warm temperatures, green-housing, and direct sun will cause an increasing danger of wet avalanches in the backcountry today. The danger will rise to level 3 or Considerable as the day heats up, and dangerous avalanche conditions will develop on steep slopes with heat-softened and melt-saturated snow. Triggered wet avalanches are likely. Large natural cornice falls and wet avalanches are possible, and you still might trigger a dangerous deep slab avalanche on a very steep slope in an isolated area with thin snow coverage. Careful snowpack evaluation, cautious route finding, and conservative decision making will be essential today in the backcountry.

CURRENT CONDITIONS

Don't get your hopes up. There certainly isn't much in the way of powder left, and this morning's supportable snow will get soft, mushy, and slow rapidly with way too hot temperatures expected today. Wind is the only weather factor working in our favor today, and the snow in exposed terrain might not heat up as much as it will where sheltered. The Tony Grove Snotel reports 44 degrees this morning, and there is 71 inches of total snow at the site, containing 83% of normal water for the date. The Campbell Scientific Logan Peak weather station at 9700' reports 39 degrees and south winds averaging in the upper 30 mph range this morning, with gusts close to 60 mph early this morning.

RECENT ACTIVITY

Earlier in the week, there were a couple near misses in the Big Cottonwood and Park City Area in the Salt Lake Zone, with people triggering and getting caught by dangerous hard slab avalanches running on depth hoar. In both cases, the riders luckily escaped.. Snow safety personnel at one mountain near Salt Lake City triggered a huge deep slab running on depth hoar using explosives on Wednesday....

In the Logan Zone, there were several small naturals and a few manageable triggered wind slabs on Monday, all involving drifted fresh snow... No large or deep avalanches were reported recently.

(go to our current conditions page for more details on the local activity and reports of many other recent avalanches and conditions in the backcountry across the mountains of Utah)

THREAT #1
WHERE PROBABILITY SIZE TREND
      Over the next 12 hours.

Very warm temperatures, green-housing, and direct solar heating will cause the already soggy snow on many slopes to rapidly become saturated and prone to avalanche. Dangerous avalanche conditions will develop. Triggered loose wet sluffs will become increasingly likely in steep terrain as the day heats up.. Loose wet avalanches could entrain large amounts of Monday's snow and pile up deeply, especially below sustained steep slopes. Wet slabs failing on moist depth hoar are possible on isolated very steep slopes with generally shallow snow and poor snow structure. Avoid travel on steep slopes above trees or other terrain traps that you might be swept into, and refrain from loitering in avalanche paths and below steep slopes with saturated snow in the heat of the day...

THREAT #2
WHERE PROBABILITY SIZE TREND
      Over the next 12 hours.

Sagging cornices are likely to be sensitive in the heat of the day, and some may naturally calve off. Cornices are likely to break further back than expected, and cornice falls could trigger deep slab or wet avalanches on steep slopes below....

THREAT #3
WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Depth hoar still plagues the basal snowpack in some areas, and you might trigger a dangerous deep slab avalanche on an isolated steep slope, particularly in areas with generally shallow and weak snow... On some slopes with poor snow structure, an overrunning cornice fall or loose wet avalanche might trigger a more dangerous and destructive deep slab avalanche...

MOUNTAIN WEATHER

Mostly sunny conditions are expected today, with mountain high temperatures a bit over 50 degrees and strong south winds. Expect mostly clear conditions overnight, with low temperatures in the mid to upper thirties and gradually diminishing southwest winds. It'll be very warm, sunny, and windy again tomorrow, and even warmer still on Sunday, with a bit less wind... Our next chance for snow will come Sunday night, but rain is likely first, and little accumulation is expected.

GENERAL ANNOUNCEMENTS

I recently published some historical photos of the Huge Wood Camp avalanche from 2-20-1986.... Click HERE

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

Please send us your observations from the backcountry especially if you see or trigger an avalanche, but also even if you don't.. go to avalanche and snow observations. You can also call me directly at 435-757-7578 or leave us a message at our office, 801-524-5304.... And, you can always send us a simple email by clicking HERE

I will update this advisory by around 7:30 in the morning on Mondays, Wednesdays, Fridays, and Saturdays.....

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.