SPECIAL ANNOUNCEMENT |
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Despite the date, continuing winter snow conditions warrant caution and awareness in the backcountry, and I will issue morning forecasts through this weekend..... |
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BOTTOM LINE
Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)
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Danger Rose Tutorial
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There's a Level 3 or Considerable danger in the backcountry, and dangerous avalanche conditions exist on upper and mid elevation slopes with significant deposits of new or especially drifted new snow.. Triggered storm snow, wind slab, and cornice fall avalanches are all likely today, but I expect things to stabilize fairly quickly... Dangerous persistent slab avalanches stepping into old snow are possible and could be triggered by smaller overrunning avalanches or cornice falls. The danger of moist or wet avalanches entraining significant fresh snow, mainly at mid and lower elevations will rise with seasonal midday warming, especially if the sun breaks through cloud cover. Careful snowpack evaluation, cautious route finding, and conservative decision making are essential in avalanche terrain. |
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CURRENT CONDITIONS |
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You'll find fantastic powder riding conditions today, especially up high in the backcountry... But use caution in steep terrain because yesterday's very productive storm also created dangerous avalanche conditions in places. The 8400' Tony Grove Snotel reports 16" of new snow as of 11:00 last night, containing 1.8" of water. There was 143 inches of total snow at the station, with 151% of average water content for the date... The CSI weather station on Logan Peak reports 18 degrees this morning at 9700', and Mt. Ogden reports south winds overnight with 20-30 mph average wind speeds and gusts of just under 50 mph.... |
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RECENT ACTIVITY |
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Before yesterday's storm observers reported easily triggering manageable moist sluffs on steep slopes at mid and lower elevations across the zone. During the intense storm yesterday I noticed evidence of fairly extensive natural soft slab and loose snow avalanche activity off the steep slopes south and west of Tony Grove Lake. I triggered cracking in the new snow and a couple small loose sluffs that entrained a good amount of fresh snow on steep but small test slopes...
.See our avalanche list HERE
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THREAT #1 |
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Over the next
12 hours.
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Human triggered soft slab avalanches consisting of fresh snow and failing on the old/new interface or on density changes within the new snow are likely this morning. But, these new snow instabilities will probably settle out fairly quickly as is normal in the springtime. You are likely to trigger loose dry or moist avalanches (or sluffs) on slopes steeper than about 35 degrees, and these could entrain significant quantities of fresh snow, especially on big slopes. The danger of moist or wet avalanches involving warmed fresh snow will increase at mid and lower elevations, especially as temperatures warm around midday. This threat will likely become more of an issue with solar warming next time the sun escapes the cloud cover... Be aware of trees or other potential terrain traps below you if you venture on steep slopes... |
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THREAT #2 |
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Over the next
12 hours.
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You could probably trigger fairly broad and dangerous wind slab avalanches up to around 2 feet deep in drifted upper elevation terrain. Wind slabs from yesterday are probably buried and obscured by a few inches of fresh snow that fell later in the storm after the winds diminished. Wind slabs formed on the lee sides of ridge lines and in and around terrain features like sub-ridges, gullies, scoops, and cliff bands.... You should avoid smooth, rounded, hollow sounding, or stiffer snow on steep slopes, especially above trees or other potential terrain traps...
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. The fresh snow and wind from yesterday will have many of these primed and ready for a hair trigger.... |
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THREAT #3 |
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Over the next
12 hours.
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Dangerous persistent and deep slab avalanches are still possible on slopes with buried weak layers and poor snow structure.. Some avalanches may break on a weak layer above last weekend's melt and older surface rime-crust that is now sandwiched below a thin melt-freeze crust formed during warmer temperatures on Wednesday. And, with all the new weight from yesterday's storm, deeper hard slab avalanches running on preserved and reactivated mid-winter weak layers are possible on steep drifted upper elevation slopes, especially in rocky areas or areas with a generally shallow snowpack. Persistent slab avalanches might be triggered by overrunning storm snow, cornice fall or wind slab avalanches... |
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MOUNTAIN WEATHER |
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The storm will gradually exit the zone today, leaving lingering snow showers, clouds, and only gradually warming temperatures in it's wake. 2 to 4 additional inches of accumulation is forecast...High temperatures in the mountains will stay in the lower 20s and sustained moderate northeast winds along the ridges will keep things chilly and continue drift the fresh snow around. The winds should diminish and shift around from the southwest this afternoon... Snow is likely overnight and tomorrow with only minimal accumulations and continued cool temperatures. |
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GENERAL ANNOUNCEMENTS |
Help us improve the information we provide. Please take the time to answer 10 quick questions in our spring user survey... click HERE
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
We will be ending our regular advisories for the season this weekend.....
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. |
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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. |
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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. |
