Based at the University of Colorado-Boulder, the National Snow and Ice Data Center (NSIDC) has no shortage of skiers experienced enough to know good—and bad—ski conditions.
Based at the University of Colorado-Boulder, the National Snow and Ice Data Center (NSIDC) has no shortage of skiers experienced enough to know good—and bad—ski conditions. “Warm days plus cold nights can really make conditions painful,” opines software developer Matt Fisher. “You get the snow warming up during the day then icing over at night. It’s harder to keep control in icy conditions and when you fall, it really hurts.” Heidi McCann, coordinator of indigenous knowledge exchange agrees, adding that the most desirable snow has low water content, and ideally, eight or more inches of fresh powder.
At an organization that collects and analyzes data on all things frozen, there’s also no shortage of skiers who are thinking about how global warming will affect conditions on their favorite slopes. Among them is NSIDC research scientist Twila Moon, who works remotely from Big Sky, Montana, and calls herself “reasonably obsessed with skiing.” She lays out the optimal conditions, which start before ski resorts open each season. “You can almost think of it as a timeline,” she explains. “Late fall into early winter is when you start to build up snowpack, when the snow layers bond together.”
Hazards to skiers during this period include hoarfrost, that can form under calm, humid, clear conditions; and ice lenses caused by surface melt or rain-on-snow events. Any snow accumulating on top of these flaky or icy layers is prone to avalanche. Depth hoar, which often forms in a shallow snowpack, can result in especially widespread instability throughout much of the remaining the season, potentially leading to catastrophic avalanches. While ski resorts try to mitigate avalanche risks, backcountry and cross-country skiers outside resorts must watch out for themselves.
Once ski season is well underway, Moon says, the best conditions are not too cold for skiers to endure or for snow to continue falling, “but cold enough to build up powder. Having dry spells, or warm weather, or rain on snow are very problematic.” She adds, “Of course there’s the year-to-year luck of the weather, but it’s now happening against a background trend of warming temperatures.”
Continue reading at NOAA.
Image via NOAA.
