Tuckerman Ravine currently has MODERATE avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Unstable slabs are possible. Use caution in steeper terrain. Hillman's Highway, the Lower Snowfields, the Little Headwall, and Right Gully have little to no snow in them so this Moderate forecast does not pertain to these areas. Forecasts for these locations will begin when needed.

Huntington Ravine is still under a General Avalanche Advisory. A General Advisory is issued when instabilities are isolated within the entire forecast area. However it's important to realize that avalanche activity may occur within these locations before the issuance of a 5-scale forecast. This is a critical fact to remember. Under a General Advisory you need to make your own avalanche stability assessments before venturing into any open slopes.

Yesterday's snow event came in quickly delivering several inches before noon. Exact snow amounts at the summit have been difficult to determine due to winds, densities, crystal type, and compaction in the can. They are recording 4.6" (11.7cm)with a water content of 0.74" (1.9cm) when melted. It is very likely the actual depth was greater before any compacting occurred. This demonstrates the difficulties of weather observations when you're dealing with the "worlds worst weather". Here at Hermit Lake we picked up 4" (10cm) of 8.5% snow by midday. Wind loading was perfect with W winds between 40-50mph (65-80kph)during the first half of the day. This built some slab instabilities in some of the larger Tuckerman snowfields. Winds continued to increase through the evening gusting into the 90+mph (145+kph) after midnight with a peak of 101 (160kph) from the N. Winds are expected to remain high for the first half of the day before moderating greatly later. Snow plumes are still visible over some start zones inducing some continued light loading. There are areas in Tuckerman on the upper end of the Moderate approaching Considerable, but aren't quite there as their natural ability to release are still unlikely. These areas are the strongest lee slopes from NW winds. Some examples include the Lip, under the Headwall ice, The Chute, and the Sluice.

Tonight into tomorrow another weather maker will bring a wintry mix to the mountains. It currently appears most of the event will be rain in avalanche terrain with amounts totaling over .5". (1.25cm). This has the potential to cause a natural avalanche cycle to occur. Rain on new cold slabs is not ideal. Be sure to reference tomorrow advisory before heading into avalanche terrain.

As we discussed in yesterday's advisory if you wanted to find some instability you could, and people did. As the actual snow amounts exceeded the forecast things changed quickly. It is extremely important to keep your mind open to the clues Mother Nature is giving you. Evaluate the conditions as you travel and always keep your mind open to changing stability. One pair of climbers released a very small pocket above the "open book" yesterday afternoon in Tuckerman. They decided to continue on rather than turn around in low visibility and blowing snow. The rest of their climb was uneventful demonstrating the isolated nature of the instability, but these are the exact type of clues that should change your plans. A similar event occurred to 2 climbers in Left Gully who were looking to summit Boott Spur. They saw the bulls-eye clue and went back down and all the way around to get to the spur via a different direction, a better tactic. The main point is when the National Weather Service says their best calculations to predict a natural event determine there should be 2" (5cm) of snow today and you're walking through 8" (20cm) don't forget that it's 8" (20cm)! The best information is what YOU are seeing as you travel, don't put your head down and say, "the weather forecast didn't predict this" while pressing on. Stop and re-evaluate. You must keep your avalanche eyes open and assess each new snowfield independently. It is critical that you focus on the consequences of what will happen to you if an avalanche occurs and not completely on their size. Your decision-making and route selection in avalanche terrain should also consider that it's a holiday weekend and more triggers are running around the mountain than usual. Always consider who may be above and below you

By now you should have refreshed your avalanche skills, installed some fresh high quality alkaline batteries in your avalanche beacon, and mastered its use. Don't forget your safe travel rules, techniques for assessing snow stability, and sign up for an avalanche course.

Avalanche courses offered in the valley this winter are now on our website, tuckerman.org.