Welcome to 2013. Let’s start with a little nugget from the Observatory, the month of January has the highest average winds speeds (46 mph) and the lowest normal monthly average temperature (4.7 F). Judging by the howling winds and frigid temps all week I’d say we are right on track. For the first few day of January the average wind was 65.8 mph which is a tough way to ring in the New Year. These cold and windy conditions have made forecasting …well…a little less than straight forward due to low or no visibility. This morning we were looking at the potential for a few inches of snow during daylight and a few more through midnight, on moderate winds – a perfect scenario for loading up our two favorite Ravines. As we continue through the night we may get those much needed inches of snow but they will get delivered on increasing winds up around 100 mph. These kind of speeds usually scour some gullies and load other areas, making for interesting Saturday morning field observations. Saturday will move toward partially cloudy skies with perhaps a few AM snow showers lingering, strong winds in the morning but slowly decreasing as the day moves on. Sunday looks a bit on the cloudy side, maybe a chance snow shower or two and a bit warmer, which isn’t saying a whole lot.
Thankfully the end of December and the start of January has been kind to us in the snowfall department, however we’re still below the norm. I know, it’s hard to look at the piles of snow in the valley and not expect there to be tons more up higher, but we’re not swimming in it yet. Anyone coming up to ski make sure you’re ready for less than thigh deep champagne powder, lots of rocks and shrubbery still poking up through the snow. Sounds just like an overly optimistic ski resort report doesn’t it?
If climbing’s your game the gullies in Huntington are getting more snow and ice like and less “scratchy mixed” each day. Mount Washington has some of the best ice making systems on the east coast, with more gullies freezing up every day. The post-holing is top notch up through some of the fan and even down lower on the trail heading in. If the expected high winds pan out tonight it should hammer the snow down in the fan making for some better traveling once you make your way out of the boulders. If the winds don’t reach high speeds you might run into a pocket or two of unstable snow as your reach the base of Pinnacle, Odell, or Central, but we’ll have better details in the morning advisory once we see how the evening winds and snow totals pan out. Be sure to give Saturday morning’s avalanche advisory a read before heading into either Ravine.
Hope to see you up on the mountain over the weekend,
Here’s the table of mean temperatures from our friends at the Mount Washington Observatory.
Tuckerman Ravine will have Considerable and Moderate avalanche danger. The Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Lobster Claw, Right Gully, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely.
All forecast areas of Huntington Ravine have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully to identify features of concern.
Strong winds and new snow are the key pieces of information to focus on today. The forecast is calling for 2-4″ of new snow along with W winds increasing to 75-95mph (121-153kph) later this afternoon. Currently, winds are already 75mph (121kph) at the summit with light snow since 11pm last night; new snow has begun to be transported into the ravines. As this continues, hard slabs will develop in protected lee areas, particularly in the center portions of Tuckerman such as the Lip and Center Bowl. Other areas will see cross-loading, the tops of Right Gully and Lobster Claw are good examples.
In Huntington, the first areas I’d expect to see instabilities develop is below the climbs, on the approach. The steep snowfields that lead up to climbs, especially Odell and Pinnacle, are common places for avalanches to occur. This is due in part to sluffing and spindrift that falls down the gully. This snow collects at the base of the ice and forms deeper slabs than in other areas of the ravine. This multiplying effect is likely already taking place and will continue through the day. As more snow falls, you can expect to see additional slab growth in other locations such as the start zones at the tops of the gullies.
Today’s avalanche hazard is primarily due to new snow loading. Prior to this, stability overall was fairly good. Many areas were at Low danger yesterday, with the dominant surface conditions being wind-hammered hard slabs. If today’s snow accumulations fall short of a couple inches, or if the winds are so strong they lead to scouring instead of loading, then we might not reach today’s forecasted ratings. Despite the impressive snowfall totals at the end of December, the mountain is still looking pretty bony. Lots of rocks and section of brush have yet to be filled in, so the size and distribution of the avalanche hazard is different from when the ravines are fully filled with snow. You should be thinking of the potential for avalanches even on relatively small snowfields.
Finally, think about the weather before you head up. Not only will low visibility prevent you from visually assessing avalanche hazard, the winds, low temperatures, and blowing snow create somewhat unforgiving conditions.
Safe travel in avalanche terrain requires training and experience. This advisory 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.
Posted 8:15 a.m. January 4, 2013. A new advisory will be issued tomorrow.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856