Huntington Ravine has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Unstable slabs are possible in steep terrain. Use caution in steep terrain.

New snow paired with WSW winds that will shift to the WNW and remain steady between 20 and 35 mph (32 to 56 kph) are the ingredients for today's growing instability. By the end of the day many areas may be on the upper end of Moderate and entering the Considerable rating. Read on for the details.

Over the past 24 hours the Summit has recorded 1.5" (3.8 cm) of new snow with a density of 12.6%. Rimed crystals account for the high density of the new snow. At Hermit Lake we recorded 3.1" (8 cm) of 10% snow. Low-level clouds are the reason for higher snowfall totals at Hermit Lake. Today's weather forecast is calling for more snow as a result of a low pressure system moving though the area. Summits are expecting between 2 and 5" (5 and 12 cm) of additional accumulation through the day. We are in a lull right now and expect the snow to pick up again around noon. Winds are currently from the WSW and will be moving to the WNW around 1:00 p.m. today. Oddly enough, they are not expected to increase as the storm passes by. So we can expect the speeds to remain steady around 20 to 35 mph (32 to 56 kph) with a potential for slightly higher winds later today. This system does not have the drama of big snow or outrageous winds to make us all react in fear and awe of nature's power. However, it is a sneaky sort of event. All seems mellow but we actually do have wind slabs forming and we think that they could be quite touchy, particularly up in the start zones. Soft slab wind drifts are all around the Hermit Lake area and the wind directions are perfect for loading all aspects through the day. Because we are expecting softer slab development, we expect slabs to be touchy in nature because your body weight will easily impact the weak layers. So what are the weak layers? I think the primary weak layer today will be unconsolidated new snow that was or will be deposited from this storm. It may also be a less dense slab that is sitting under a denser slab. These stratifications in the new snow may be subtle and hard to detect. Surface hoar is another character worth mentioning that may play a role as a weak layer. Yesterday morning we had impressive surface hoar, particularly around 3800'. While it was less developed, it was still present in the Fan in Huntington. Take a look at the most recent photos we put on yesterday to see what we are talking about. Sunny and seasonably warm temperatures yesterday melted most of the surface hoar, but it may be a factor on shady aspects. Of course all of this is sitting on the massive rain crust we have been raving about. This crust is rough which is good for keeping things in place. It is also very slippery which is bad for keeping things in place. I think the slippery nature out-weighs the benefit of the rough surface. The bottom line is new slabs will be forming through the day. We think that human triggered avalanches are possible and by the end of the day, as more snow has fallen and loaded into the Ravines, we think we could be entering the Considerable rating. If we receive more snow than we are expecting or winds exceed their forecasted rating, we could enter the Considerable rating earlier in the day. Pay attention to the weather!

THE LION HEAD WINTER ROUTE IS OPEN. Mountaineering skills and equipment are required for safe travel on this route.

The Sherburne Ski Trail is open and has coverage though it's very thin in places. Expect new snow over a hard and unforgiving icy base.

As always, this advisory is one more tool to help you make your own decisions in avalanche terrain. It should be used along with your own snow stability assessments, knowledge of safe travel techniques, skill in reading mountain weather's effect on the snowpack, and avalanche rescue. To improve these skills take an avalanche course. We have all the avalanche courses offered in and around the Mt. Washington Valley this winter on our website, tuckerman.org.