An Avalanche Warning remains in effect for the northern Utah mountains and extreme southeast Idaho through Friday morning. Heavy snow, strong winds and warming temperatures have created a High to Extreme avalanche danger. Avalanches are occurring at unusually low elevations in addition to the more typical mid and upper elevations. Both natural and human triggered slides are certain.
Current Conditions:
Snow continues to fall in the mountains this morning, with storm totals now in the 2 to 4 foot range. The snow water equivalents are astounding – averaging 3” to over 6”. Winds were strong from the southwest yesterday, averaging 20 to 40 mph. Recently, they have shifted to the northwest and are in the 15 to 30 mph range, with gusts in the 40’s. Temperatures have warmed 5 to 10 degrees since yesterday morning, and are in the mid to upper 20’s. The warm temperatures and wind inverted the snow, putting a layer of dense heavy snow on top of yesterday’s lighter snow.
Avalanche Conditions:
This storm has slammed the buried weak layers with just about every known contributory factor there is to cause avalanches – lots of snow, enormous water weights, warming temperatures, wind and rain falling on snow at the lower elevations. By yesterday afternoon, widespread avalanche activity was reported from throughout the northern Utah mountains. There was natural activity, skier triggered slides and remotely triggered slides. Some slides were running in the new snow only, while others were breaking 2 to 4’ deep into the old November weak layers.
The weak layers of surface hoar and facets are widespread. They are weakest at the lower and mid elevations, and in normally wind sheltered areas. Many slides have been occurring in terrain between 6,000 to 8,000 feet, in addition to in the upper elevations. Even in low elevation terrain, stay off of and out from under slopes steeper than about 30 degrees as it is possible to trigger slides from a distance. Large natural avalanches are occurring in some areas, so stay out from under steep slopes and avoid runout zones.
Ice Climbers – most northern Wasatch ice climbs are in avalanche tracks. With natural avalanche activity likely, ice climbing is not recommended.
Bottom Line (Salt Lake, Park City, Provo and Ogden area mountains):
The avalanche danger is HIGH to EXTREME on and below all slopes steeper than about 35 degrees, especially with recent deposits of wind drifted snow or areas receiving rain on snow. Both human triggered and natural avalanches are certain above about 6000 feet. Slopes of about 30 to 35 degrees have a CONSIDERABLE danger. Backcountry travel is not recommended.
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