Avalanche Data: The avalanche averaged 4’ in depth, was 600’ feet wide, running for about 500’ vertically. Classified as a HS-AM-D2-R3-O/G. The avalanche failed on a thin layer of faceted snow above the Thanksgiving raincrust.

Weather and Snowpack History: The western Uinta snowpack is historically plagued by cold temperatures, shallow snow depths, very weak snow and strong winds… at face value, this year was no different. October was unusually dry and warm, though winter got rolling with an Election Day storm which deposited several feet of snow to the upper elevations. A warm, dry November followed rapidly settling total snow depths to about a foot. All south facing aspects shed their winter coat and reverted back to grass and bare rock. Two inches of snow fell on the evening of Friday November 29^th.  However the bigger news was November went out with a bang of sorts. A moist, misty northwest flow moved into the region on the afternoon of November 30^th and rain fell to the highest peaks forming an unusually stout raincrust which still plagues our snowpack.  

A colder northwest flow followed, ushering in December with a small storm depositing 3” of snow and strong ridgetop winds on Dec. 2^nd followed by another quick hitting system on Dec. 8 with 8” of snow. Very strong prefrontal southwest winds raked the upper elevations on the evening of Dec. 12, gusting into the 70’s along the high ridges and peaks. Nearly a foot of light density snow fell overnight, overloading the fragile weak layers of the pack. The Dec. 13 advisory warned of the possibility of slabs breaking to the ground  on old layers of snow and test slopes confirmed our suspicions. Another 8” of snow fell on Dec. 16^th.  An Avalanche Warning went into effect on the morning of Dec. 20 as new snow and hurricane force prefrontal winds continued to overload the structurally challenged snowpack. While the warning expired, a HIGH avalanche danger remained at the upper elevations, especially on north facing slopes that held snow during the November dry spell. A powerful Pacific system moved into the region on the 22^nd depositing 16” of snow, followed by the Christmas storm which walloped the area with an additional 2’. Water totals were just over 2” in seven days. The Avalanche Warning remained in place through Dec. 27^th and was downgraded to a Special Avalanche Advisory on the 28^th. However, we strongly worded the advisory cluing people into the severity of the conditions and the consequences of triggering large, dangerous and possibly unsurvivable slides on slopes approaching 30 degrees in steepness.