BEND – Winter brought above average snow to the Central Cascades. Then a summer heat wave melted most of it.
Now, glaciers in central Oregon could be melting significantly as the snow that normally protects them in the warmer months disappears.
Rapid snowmelt in spring and early summer has left midsummer snowmelt at an all-time low, said Larry O’Neill, associate professor at Oregon State University’s College of Earth, Ocean and Atmospheric Sciences. In addition, this snow season – with its unusually rapid meltdown – will become the new normal, he said.
When the snowpack melts at the beginning of the year, it can have negative consequences for water resources and the health of glaciers. Reservoirs can be difficult to fill, river levels remain lower than normal, and grazing land can deteriorate. For those who enjoy climbing Mount Jefferson, North Sister, and other peaks in central Oregon, it can mark an early end to the multiple mountain climbing season.
“The slightly warmer spring and the June heat wave melted almost the entire snowpack,” said O’Neill. “We started the spring in the Central Oregon Cascades with almost normal snow cover, but unfortunately it melted about three to four weeks earlier than normal.”
The consequence of this is that in late summer less snow melts into streams, which results in streams flowing at a lower level than normal. This can affect the habitat for fish and wildlife. The weak snow cover in late summer also dries out the forests and creates conditions for wild fires.
“This snow season is a perfect example of what the future will be,” said O’Neill.
Glaciers melt faster when the protective blanket of snow disappears, said Anders Carlson, president of the Oregon Glaciers Institute, a nonprofit that supports glaciers through science and education.
“This is going to be a very bad year for them,” said Carlson. “Because the snow retreats and disappears so quickly, the glacier below will melt faster than in normal years.”
The melt comes amid the historically hot weather in central Oregon. The temperatures measured in Bend reached an all-time high at the end of June and culminated in 107-degree weather on June 30th. In Warm Springs on June 27th, the temperature rose to 119 degrees, setting a state record.
June of that year was the second warmest June on record in 1895, O’Neill said. June of this year was 8 degrees above normal compared to the record 8.3 degrees above normal in June 2015.
According to Carlson, the flimsy snowpack combined with the hot temperatures is a double blow that may be driving the glacier melt at high speed.
“This can be a force multiplier, but in a bad way,” said Carlson. “Longer periods in which more glacier ice is exposed to higher temperatures means a bad year for the glaciers.”
In recent years, Mount Bachelor, Broken Top, and Three Sisters have been covered in snow even in summer. The Collier Glacier on the western slopes of North Sister would also be covered in snow.
While the sight of so much exposed mountains at this time of year may be terrifying to some Bend residents, seasoned mountaineers say they are getting used to the snow-free skyline west of town.
“I’m not surprised,” says Cliff Agocs, co-owner of Timberline Mountain Guides, which runs mountaineering tours in the Cascades. “I’ve been working in the mountains of Oregon for 12 years now and I’ve only seen slow or fast progress depending on how you look at it.”
Agocs blames climate change for the rapid loss of snow in the Cascades every summer. Temperatures in Oregon have warmed an average of 2 degrees over the past century, and snowpack has fallen 20% since 1950, according to the Environmental Protection Agency.
A report published in January by the Oregon Climate Change Research Institute said temperatures will rise 5 degrees by 2050. She adds that by the middle of the 21st century the number of snow days will halve compared to the values at the beginning of the century. The institute predicts that the snow cover will decline by 60% by the middle of the century.
Since climbing is safer when loose rock is still frozen together, Agocs’ guided climbing tours end when the mountain peaks thaw. Ten years ago that meant going up by the beginning of August. The trips now end at the beginning of July.
“This type of change shouldn’t be apparent to a person for over a decade,” said Agocs. “It’s really fast.”