CONWAY — No one was injured, but officials are advising extreme caution after two groups of skiers had a very close call Saturday with an avalanche in the southeast snowfields below the summit cone of Mount Washington.
Frank Carus, a U.S. Forest Service snow ranger and a forecaster at the Mount Washington Avalanche Center, on Monday said the avalanche was unusual in that the area where it occurred "historically doesn't produce many avalanches" and also because the avalanche was "on the large side: about a meter deep on average, 200 meters across on the crown line and about 10 acres in total, with four acres of debris."
"The take-home is that even though it's spring, we're still in winter mode in the mountains so avalanche hazards still exist and proper precautions should be taken. Fortunately, nobody was caught in this incident although a lot of people were really close by."
Carus said the avalanche happened around 1 p.m. Saturday, adding it was reported to authorities half an hour later by the caretaker of the Harvard Mountaineering Club Cabin, which is located below Tuckerman Ravine at a height of 3,250 feet.
The caretaker was out enjoying the day and witnessed the avalanche, reporting it via radio to the avalanche center. The first snow rangers, including Carus who was accompanied by Lily" his chocolate lab avalanche-rescue dog, were on scene at approximately 2:20 p.m.
"There were skiers and what this is technically known as is a 'remote trigger,'" Carus explained. "The crack wasn't really at their feet. The slope they were on collapsed but the energy was transmitted through the slab and it cracked on the slope behind them. The slope failed between the two parties but didn't hit any of them."
There were approximately 30 people in the southeast snowfield at the time of the avalanche and when the snow rangers arrived they joined them in searching through the debris. Lily, who's still in training, assisted.
An avalanche-rescue dog like Lily seeks out what Carus called "scent plumes" in the snow and although still learning her job, "she's useful particularly in our area where people often go into avalanche terrain without an avalanche transceiver (also known as an avalanche beacon) and without one there are not many good ways to find them without a dog or a Recco unit."
A Recco unit, Carus said, "is a little chip implanted in ski clothing and ski boots which works in tandem with the receivers that we have. They're a means of finding someone when they don't think they need a transceiver, but back-country skiers should always use an avalanche beacon and use safe travel techniques."
An avalanche beacon costs more but everyone should use them, Carus said, "because it's cheap insurance relative to your life." Anyone headed up Mount Washington this time of year, he added, should also carry an avalanche probe and a shovel.
The avalanche center on Saturday issued a "moderate" avalanche warning for Tuckerman Ravine and Huntington Ravine "and while we don't forecast specifically for the summit cone, the avalanche problems we talked about in Tucker and Huntington were very relevant," said Carus.
In unofficial parlance, he said conditions on Saturday were "scary moderate," in that there was a possibility of a large avalanche even though the probability was low.
Carus said the skiers who were in the southeast snowfield on Saturday "were lucky not to be in its path. This is not something where you quickly scoot out of the way. If you were anywhere on the slope it's hard to imagine people surviving it. People typically die when they're buried more than three-feet deep and this was up to 20-feet deep."
In trying to determine what precipitated the avalanche, Carus thinks there was "a convergence of factors.
"There were a lot of people entering the mountains that now have well-developed avalanche paths and warm conditions in the alley lead people to believe it's spring-like, stable snow but in fact we still have winter conditions."
Basically, he summed up, "The more people you put into the terrain the more likely you are to have accidents."
The Mount Washington Avalanche Center will continue issuing avalanche forecasts until June 1, said Carus, after which "we'll do forecasts for other hazards" on Mount Washington, including crevasses and ice-fall hazards.