This advisory expires tonight at 12:00 midnight.
Tuckerman Ravine has Considerable and Low avalanche danger today. The Sluice, Lip, Center Bowl, Chute, Left Gully, and Hillman’s Highway have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. All other forecast areas of Tuckerman have Low avalanche danger. Natural and human triggered avalanches are unlikely. Unstable snow may exist in isolated terrain features in areas rated Low.
All forecast areas of Huntington Ravine will have Low avalanche danger today. Natural and human triggered avalanches are unlikely. Unstable snow may exist in isolated terrain features in these locations.
AVALANCHE PROBLEM: Newly formed windslab will be the primary avalanche problem today, thanks to last night’s snow and what may fall today. You’ll find this problem in the well-protected areas where strong winds have a lesser effect. In Huntington, this is often down in the bottoms of the climbing routes. Even though these routes are rated Low, whenever you encounter fresh windslabs on the crust, the little avalanche warning bells inside your head should be going off. In Tuckerman, the Lip and Center Bowl are the areas of greatest concern; they are the most sheltered from the winds. Outside of these locations, expect more wind effect on the slopes and slightly better stability. For all areas rated Considerable, the rating is due to the possibility of natural avalanche activity on these slopes.
WEATHER: Yesterday was a miserable morning on the mountain. Warm temperatures and heavy rains turned the entire Tuckerman Ravine Trail below Hermit Lake into a sloppy slush flow. Thankfully, we’ve dipped well back below freezing. We recorded 2” (5cm) of new snow at the Hermit Lake snowplot this morning. Today there is a chance for an additional trace to 2” of upslope snow showers. The falling temperatures will continue and winds will ramp up with gusts in excess of 100mph (162kph) by this afternoon. This will not make conditions above treeline very comfortable—be conservative if you are heading up high today.
SNOWPACK: There’s not much to say about the depths of the snowpack today. The reset button was pushed yesterday when the temperatures began falling below freezing. Concerns today are limited to the couple inches that’s being blown about and any new upslope snow that might come. At Hermit Lake, I am seeing some drifts as deep as my boot-tops from the 2” of snow. In Tuckerman, I suspect the drifting is deeper. This would be creating unstable windslabs sitting on top of a rain crust, which is generally a dangerous combination. So if you were to brave the cold and wind, you’d find some areas blown clean down to shiny new crust, in other locations you may find a dust-on-crust situation, and in other locations you’ll the deeper drifts of windslab. My feeling is that the Chute, Left Gully, and Hillman’s will be moving toward Low danger late in the day due to heavy wind effect. However, I recommend taking the conservative approach until visibility improves and better assessments can be made.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856