Avalanche Forecast for Sunday, February 10, 2019
This information was published 02/10/2019 at 6:34 AM.
The Bottom Line
A stable snowpack exists thanks to a warm and wet week followed by a bitter cold and windy weekend. Avalanche problems will be hard to find today and are greatly overshadowed by the potential for long sliding falls. All areas have LOW avalanche danger.
The significance of a long, sliding fall and danger of a small stumble on seemingly benign terrain cannot be overstated. If you have not practiced self arrest with an ice axe you should. If you have practiced, you know that the effectiveness of this skill is limited in the hard icy snow you’ll encounter in the mountains today. In these conditions, very careful movement is necessary to prevent a fall from happening in the first place. Put crampons on before slopes steepen and get your ice axe out and ready before you expect to need it. Crampons and ice axes cause injuries almost as often as they prevent them, so never practice self arrest with crampons on or on a slope without a clean and flat runout.
Every weekday this past week saw high temperatures at or above freezing on the summit. The hard freeze began Friday morning with temperatures on the summit bottoming at -13F. Extreme wind was also in play as Saturday’s wind averaged 87 mph with a gust of 148 mph. Friday and Saturday each came with a 0.2” of snow recorded on the summit and a trace falling Friday at Hermit Lake and Grey Knob snow plots. Today, NW wind in the 60-80 mph range will decrease just slightly through the day. Current temperatures at the summit (-11F) and Hermit Lake (-2F) will increase by about 10F. Morning summit fog should clear out before high clouds arrive in the afternoon. No snow is forecast until Tuesday afternoon.
The melt/freeze crust that developed from this past week’s weather should now be supportable at mid and high elevations. Observations from yesterday indicated that the crust was breakable in the trees and at elevations below 3500’. Small, isolated pockets of wind slab may exist in sheltered areas below cliffs, rocks, or other terrain features, but the limited snow available for transport combined with wind speed seems to have moved most snow into the trees and out of avalanche terrain. While this past week left us with a crust, the minimal amount of rain that fell meant that we did not lose much snow. Height of snow at the Hermit Lake snowplot is down about 6” and Gray Knob is down close to 8”. The storm arriving Tuesday night should help replace this loss, though it will fall on the icy crust that will provide an ideal bed surface for future avalanche cycles.
The Sherburne and Gulf of Slides ski trails are snow covered to Pinkham Notch.
Safe travel in avalanche terrain requires training and experience. This forecast 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.
Avalanche danger may change when actual weather differs from the higher summits forecast.
For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.
Posted 02/10/2019 at 6:34 AM.
USDA Forest Service
White Mountain National Forest