As we expected several morning hours of additional light snow gave us about another inch (2.5cm) by noon yesterday. This kept us within the Moderate rating as some strong lee areas picked up new snow while exposed areas to west winds were kept scoured clean. This will play into the next round of precipitation moving in later today as variable surface conditions will provide different bonding strength at the interface between the new and old layers. The Low pressure system we have been discussing is right on schedule as it should pass directly north of us early tomorrow morning. As it approaches we should see some snow showers this afternoon along with shifting winds to towards the SW with diminishing velocities. The wind shift should continue and models are expecting them to go all the way to 180 degrees, or directly from the S. Temperatures will begin rising this afternoon until roughly midnight before dropping again. Snow will fall into this evening probably blending in a nice "wintry mix" causing snow densities to increase which in turn will also increase instabilities. As the Low passes colder Canadian air should mix back in turning mixed precipitation back to snow. This will be associated with the wind direction shifting yet again moving back to the W during the early morning hours. This shift will continue through the day settling in from the NW and increasing. Some key things to watch with this system are 1. the melted water equivalents, 2. exact temperatures and 3. The wind shift with increasing velocities tomorrow. Currently the forecasted water equivalents for the mountains sit between 0.5 and 1.0 inch (1.25-2.5cm). This will obviously be critical to actual snowfall amounts. However the main factor will be tied to the temperature regimes of the passing system and how much sleet we will get compared to snow. Models have us awfully close to freezing up high, but for how long is the question. As winds shift and increase tomorrow we could see dramatic loading of both ravines. This will be very dependent on how heavy the precipitation densities are and what temperatures show their face over the next 24 hours. As it appears right now certainly anticipate an increasing avalanche danger for tomorrow. We will be watching this system and the "bull's-eye" information with eagle eyes.

Until then the main concern with any new snow loading in later today is the hard icy surface in many areas. Expect the bonding at the old-new interface to be less than ideal. Due to variable conditions do frequent stability tests and don't be happy with one set of results.

The calendar may not say so, but we have mid-winter snow depths in some locations and many avalanche paths are well developed. So if you are planning a trip you need to be ready to deal with full winter conditions including avalanche terrain. While traveling in avalanche terrain you need to be mindful of changing conditions. You may travel through snowfields broken by rocks and bushes and quickly enter a larger snow slope. Both should be treated with respect during times of instability. If a snowfield is big enough to recreate on it's big enough to avalanche.

As is typical this time of the year we have been in and out of warm weather so icefall potential should be kept in mind. Many folks have been injured and killed by falling ice so pay attention to where you are, and don't linger when under ice. Have a plan in mind about what you will do and where you will go if ice comes down. Station yourself near a large rock to duck behind in the event of icefall.

Don't wait any longer to refresh your avalanche skills. Pull out your beacon and practice. Review your safe travel rules, techniques for assessing snow stability, and sign up for an avalanche course. We now have all the avalanche courses offered in the Valley this winter on our website, tuckerman.org. Sign yourself or a loved one up now!