The quick moving clipper system that brought 9.6" (24cm) of 8.6% snow to the summit yesterday made it feel more like Christmas than Thanksgiving. As forecasted, snow began yesterday morning which became heavy at times between noon and 3pm before tapering off into the overnight. Precipitation concluded a little quicker than anticipated, but in the end brought in the expected accumulations just the same. As we also discussed in Thursday's Advisory avalanche danger increased late in the day and into early this morning due to the afternoon snow and shifting winds. Light snow densities and the wind shift from the SE to the NW are the critical factors to focus on today. Snow began early yesterday morning with SW winds which shifted towards the SE and held for several hours till 2pm. Wind velocities peaked for the period from the SE at 77mph (124kph). As the low moved north winds rapidly shifted again to be out of the W/WNW. Since this occurred yesterday afternoon wind direction has moved back and forth between the NW and the W where it should hold for the day. The tight pressure gradient at the tail end of this low system should generate gusts out of the W approaching 80mph (130kph). The importance of this wind discussion is all aspects of our east facing Ravines have received new loading over the past 24 hours. The most significant period to be concerned about began yesterday afternoon and will continue through all of today. High W and WNW winds have loaded new slabs into easterly aspects creating instability. I believe the variability of stability has continued to increase. Based on the early season snow coverage and high W winds today you will find some strong lee areas on the upper end of Considerable while other locations within 330 feet (100 meters) or less having much greater stability. Spatial variability is often greatest at this time of the year due to the distribution of snowfields and therefore bed surfaces for new snow to avalanche. Keep this in mind today and over the weekend as you recreate in the Ravines. It's important to not rely on one snow pit or stability test, but to constantly be seeking information, keep your avalanche eyes open, and think through your intended route. Consider what stability you might be standing in later once you enter the strong lee of westerly winds.

Ask yourself this question "Boy I really want to climb today, but will it be more unstable under the Headwall and the Lip of Tuckerman Ravine and high in the gullies of Huntington than down here?" Lets ask some more questions to answer that. "Did we get new snow in the past 24 hours?"-YES in fact the mountain has received over 23" (56cm) in the past 3 days. "Have winds been out of our prevailing W and NW loading new snow into lee areas with easterly aspects?"- YES and winds from 50-80mph will continue this today. "Will stability tests have a difficult time accurately assessing snow strength in situations with great spatial variability?"- YES "If strong winds are blowing snow limiting visibility can I assume loading is occurring?"- YES. "If poor visibility keeps me from seeing avalanche terrain above am I asking for trouble?"- YES. "Do I need to be standing in the middle of a easterly facing slope in the strong lee of W winds after 9.6"(24cm) of new snow to know it will likely be unstable?" NO. So the answer to the original question of will I find unstable slopes in sheltered lee areas of W winds the answer is YES.

Use caution this weekend, as improving weather will be tempting. Remember not to look at the blue sky, but to the stability of the white snow. If a snowfield is big enough to recreate on it's big enough to avalanche. Don't wait any longer to refresh your avalanche skills. Pull out your beacon, practice, and spend a couple bucks on a fresh set of high quality batteries. 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!