Issued by Toby Weed on Friday morning, February 19, 2021
DANGEROUS AVALANCHE CONDITIONS EXIST.
There is CONSIDERABLE avalanche danger on many steep slopes in the backcountry today. Dangerous avalanche conditions exist, especially on drifted upper elevation slopes, and accumulations of new snow and drifting from intensifying southwest winds will cause the danger to rise and become more widespread. Natural avalanches are possible and people should continue to avoid steep avalanche prone terrain because very dangerous human triggered avalanches are likely.
Use extreme caution in the backcountry. Expect unstable snow conditions.
Choose safe routes in low angled terrain well out from under and not connected to drifted slopes steeper than about 30 degrees.
Conditions are perfect for avalanche accidents. Heavy snowfall and drifting from strong winds have overloaded an exceptionally weak snowpack leading to extremely dangerous avalanche conditions.
All the fresh Utah powder will likely lure people into dangerous avalanche terrain, and people are likely to trigger deadly avalanches. A brief break in the weather will allow the avalanche danger to drop slightly; however, people can still trigger large and deadly avalanches if they venture onto steep slopes.
Avalanches triggered by people could be extremely large, very dangerous, unexpected, and deadly.
The Utah Avalanche Center recommends people avoid travel on or underneath slopes steeper than about 30 degrees in the backcountry for the next several days.
.Even if you are experienced and have the proper avalanche safety equipment, you should still avoid all steep slopes in the backcountry.
Special Announcements
The UAC in Logan is offering a Youth BC 101 avalanche class for youth aged 16-20 on Feb 21. For more info and to register, click HERE
Weather and Snow
It's 15°F at the 8400" Tony Grove Snotel, with an inch of new snow. There is 81 inches of total snow and now 84% of normal SWE. South-southwest winds are drifting snow this morning, blowing around 27 mph and gusting into the mid 40s at the 9700' CSI Logan Peak weather station.
Very large natural avalanches were widespread across the Logan Zone on Tuesday, Tuesday night, and Wednesday. In several areas, natural avalanches were incredibly extensive, with nearly all avalanche paths producing big slides. We went back up to Wood Camp yesterday to check out a huge natural avalanche that was reported on Wednesday morning.
Snow is expected in the mountains today, with 3 to 7 inches of accumulation possible. High temperatures at 8500' today will be around 25°F, but with increasing southwest winds, wind chill values will be as low as -9°F. Snowfall will intensify tonight and continue tomorrow, with 8 to 16 inches of accumulation possible on upper elevation slopes by evening. The weather pattern appears unsettled heading into next week.
Recent Avalanches
Clearing revealed that a significant natural cycle occurred across the Logan Zone, with many huge avalanches having occurred late in the big storm, (Tuesday night---->early Wednesday morning). Very large natural avalanches failing on a buried sugary persistent weak layer and running well out into lower elevation runout zones were widespread and occurred on slopes facing every direction. Reports of extensive and giant natural avalanches include most avalanche paths in the Wellsville Mountain and Mount Naomi Wildernesses, in Upper Spring Hollow, and Wood Camp Hollow. Big avalanches were also reported near Tony Grove Lake, Providence Canyon, Dry Canyon, and in the Bloomington Lake Area above Bear Lake.
A large natural avalanche was observed yesterday off the north shoulder of Logan Peak in Upper Spring Hollow. (Wally)
Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Heavy snowfall and westerly winds added significant weight to slopes that were already near the tipping point. Buried persistent weak layers consisting of sugary faceted snow are widespread across the Logan Zone, and the threat of large and deadly avalanches failing on weak snow near the ground is quite real. Avalanches are likely where a slab of more cohesive wind drifted snow formed on top of the weak snow.
Avalanches failing on a buried persistent weak layer might be triggered remotely, from a distance, or worse from below!
Cracking and collapsing of the snow are a red flag, indicating unstable snow conditions.
Avalanche Problem #2
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Avalanches of wind drifted snow are likely where drifts formed recently and are building today on slopes with buried persistent weak layers.
Additional Information
Do you have the essential avalanche rescue gear (transceiver, probe, and shovel) and do you know how to use them? Watch this video to see how the three pieces of equipment work together. HERE
Please keep practicing with the Beacon Training Park at the Franklin Basin Trailhead. Test yourself and your riding partners. It is free, fun, and easy to use.
General Announcements
Thanks to the generous support of our local resorts, Ski Utah, and Backcountry, discount lift tickets are now available. Support the UAC while you ski at the resorts this season. Tickets are available here.
EMAIL ADVISORY. If you would like to get the daily advisory by email you subscribe HERE.
Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche observations....HERE. You can also call us at 801-524-5304, email by clickingHERE, or include #utavy in your tweet or Instagram.
I will update this forecast by around 7:30 tomorrow morning.
This forecast is from the USDA Forest Service, which is solely responsible for its content. The forecast describes general avalanche conditions and local variations always occur.
