Post Rain Conditions & Wet Slab Avalanche

April 1, 2022 at 1:00 PM
Name: Ryan Lewthwaite| MWAC
Location: Center Headwall and Sherburne Trail

Around 1PM I entered Tuckerman Ravine with S2 snow, overcast skies, 33F degrees, and light west winds. Over 3/4 of an inch of rain fell and a significant amount of settlement had occurred within the snowpack across all aspects in the middle and upper elevations. It was observed by hermit lakes weather station that around 6 inches of snowpack was lost over the last 24 hours. Water had saturated the snowpack as far as I could dig in several locations. Large sections of water ice and previously covered vegetation is now exposed and devoid of snow.

A large avalanche was seen in the location of the center headwall and stretched over into the lower portion of sluice. This R2D2 avalanche is the primary photo below and was borrowed from a pair of skiers I encountered. This wet slab avalanche originated from the falls above and was 2 feet thick at the crownline in some locations. It was a naturally occurring hard slab of snow that propagated almost 175 feet across and ran over 300 feet in length. The intact chucks of debris were hard and had sections of old bed-surface within. I believe the avalanche occurred in the early morning hours just after the heaviest downpours. WS-N-R2-D2-O

The Sherburne and Tuckerman Trails are in poor condition. Exposed rocks and ice are common, and with freezing temperatures expected tonight a lock-up is inevitable. Crampons are necessary even on low angle slopes. Several larger sections of the trail are bare ground and ice and the section below Davis Path has been closed.