A new General Bulletin will be issued if conditions warrant or within 72 hours of this release. General Bulletins are issued when isolated areas of unstable snow may exist within the forecast areas. Forecasts using the 5-scale danger rating system will begin when snowfields and bed surfaces become more developed. Please remember that avalanche activity may occur before the issuance of a 5-scale danger rating forecast. As always, make your own snow stability assessments when traveling in avalanche terrain.
Over the past week we have received 12.6″ (31cm) of new snow with high W winds. This has increased the size of our isolated bed surfaces in prelude to this weekend’s weather maker. 4-8″ (10-20cm) of new snow is expected today (Saturday) with a light to moderate wind, shifting from the SE to the SW, eventually coming from the W late in the day. Overnight, winds will grow to hurricane force which should ramp up loading into our east facing Ravines. This will be exacerbated by an additional two inches of snow. Anticipate increasing isolated instabilities to develop through the weekend.
Across the entire forecast area, the potential bed surfaces are still limited and isolated, though they are certainly going to be growing with this weekend precipitation event. The largest of these snowfields can be found in Left Gully, the Chute, and in the Lip region of Tuckerman. In Huntington, Central Gully holds the largest snowfields, but others exist in various locations, such the base of Pinnacle and Odell gullies. Don’t let the lack of a danger rating lull you into complacency. Traveling through small snowfields can put you into or underneath unstable snow, and all of these pockets are going to be subjected to additional load over the next few days. This situation is a very typical scenario we go through each season as snowfield continuity and larger bedsurfaces push us closer to a daily 5 scale danger rating forecast. The only atypical thing this year is how late into the season this is occurring. Isolated areas may harbor snow instabilities, but they are only a small overall percentage of our forecast area. Many of you may be searching for these handful of locations to pursue your sport rather than the brush and rock that dominate the Ravines. If this is you, expect instability until proven otherwise by your stability assessments. There may also be a small number of you that plan on trying to follow the Tuckerman and Huntington summer trails through each Ravine. This is not a good idea as they both run through some snowfields that harbor potential hazards. Save the summer trails for summer. Finally, recognize this holiday weekend will have many others out and about that could be potential triggers above you. Mount Washington can be a busy place.
- Safe travel in avalanche terrain requires training and experience. This bulletin is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
- Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
- For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin. Bulletin posted at 645am, Saturday, January 16, 2016.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856