AVALANCHE UPDATE: Storm w/ heavy precipitation, gale-force winds, temps to 7C expected Wed.-Thurs.; evacuation extended through New Year’s


A storm expected to bring heavy rain and sleet, gale-force winds and temperatures up to seven degrees Celsius between midnight Wednesday and Thursday night presents a risk of new avalanches, according to officials who have extended an evacuation order for 80 residents with homes in the highest-risk area through New Year’s Day.

The storm could bring up to 20 millimeters of precipitation – about the same as the snowfall that triggered the Dec. 19 avalanche that buried 11 homes and killed two people, although that storm occurred over a period of several hours – and winds up to 50 kilometers per hour, according to the Norwegian Meteorological Institute. The heaviest rainfall and highest temperatures are expected Thursday afternoon.

“Precipitation, rising temperatures and southwesterly winds present a risk of avalanches,” notes an assessment posted Monday evening by Norwegian Geotechnical Institute after an expert surveyed Longyearbyen’s snowpack during the afternoon. “It is expected that locally there will continue to be persistently weak unstable layers in the snowpack. All traffic in the terrain of the buildings affected should be avoided.”

The assessment notes snowpack in the mountains on the east side of town – considered the most at-risk – has “decreased clearly from yesterday,” which for now is a stabilizing factor. But the approaching storm could trigger a slide in the dense layer of snow and ice, resulting in the decision to extend the evacuation order.

“The weather forecast looks better from Friday, Jan. 1, January, but there will be a new thorough avalanche assessment that day,” a statement posted Monday at The Governor of Svalbard’s website notes.