CORVALLIS, Ore. - Snowpack measurements have been lagging behind the long-term average in recent winters, but it may be even worse than we think - and it all comes down to taking a look at an old concept in a new light...
But in order to get a better look at the future, we first have to understand the past.
"When my colleagues and I first looked at trends in snowpack back in the early 2000s, we saw roughly two-thirds of sites in the Western U.S. saw declines," said Dr. Philip Mote, the state climatologist at Oregon State University.
Mote has been studying climatology for more than 3 decades.
He said he is seeing even more of a decline in recent years.
"When we published an update last year, that percentage had jumped to 90 percent," he said, "so 90 percent of places we've been monitoring the snow have declined."
And those numbers may underestimate the changes we've seen.
That's because of a cooler ocean La Nina-like weather pattern which disguises warmer climate trends.
Dr. Nick Siler at Oregon State just last month published a report on the subject which confirmed the losses are greater than we think.
"Over the past 30 to 40 years, we've seen more warming in the western tropical Pacific than the eastern tropical Pacific," Siler said, "so it's been a shift to a more kind of La Nina-like pattern."
So we have seen more winter snowfall - even though we are seeing more winter warming.
"It also brings an increase in winds off the Pacific Ocean, so there's been an increase in moisture transport into the West Coast," Siler said, "and so it's led to a pretty significant increase in precipitation."
That has been enough to keep our snowpack declining, but stable.
But without that La Nina, we would be left with a very different outcome
"Our best guess is that snowpack has declined by about 38 percent over the last 35 years as a result of global warming alone," Siler said.
And if La Nina reversed, we would be in big trouble.
It would endanger our snowpack and leave our mountains looking very different in the decades to come.
"For most years, the snow would be confined to the highest mountains and your highest ski resorts like Bachelor would struggle, but they'd still be skiable for at least part of the winter," Mote said, "but come spring there would be very little snow left."
It's a future scenario that could pose some serious economic issues for not only winter recreation in Oregon - but also on the ability of farmers to irrigate crops in the Willamette Valley.
PART 2 | Coming Thursday, Feb. 21, a look at the economic impact of dwindling snowpack #LiveOnKVAL at 11 p.m.