A new federal forecast says the odds now favor a cold and wet winter throughout Washington, a change from previous outlooks.
The National Weather Service’s Climate Prediction Center on Thursday released its U.S. forecast for January, February and March.
The center noted that the biggest change from November’s outlook was the increased probability of cold weather in Washington. Plus, Western Washington, like Eastern Washington, can now expect above-average precipitation.
Previously, the center said it was a 50-50 bet which way Washington’s winter would tilt. The center described the swing toward a harder winter as a “modest” change in the odds.
“It’s not really a strong forecast. It’s just a nudge that way,” Washington State Climatologist Nick Bond said Friday.
Still, the revised outlook and early snowfall bodes well for summer irrigation, he said.
“I think you have to expect that we’ll have a good snowpack coming out of this winter. I’m ready to be wrong. In this business, you have to be,” Bond said.
As of Friday, snowpacks around the state were at least 75 percent of normal, according to the Natural Resources Conservation Service.
The snowpack in the Olympic Mountains was 170 percent of normal. Olympic Peninsula farmers depend on snow melting into the Dungeness River for irrigation. The snowpack was less than 10 percent of normal during the 2015 drought.
Bond said that a “weak” La Nina — a cooling of the Pacific Ocean — is having a stronger than expected influence over the weather.
La Nina years typically, but not always, produce cooler and wetter Northwest winters. Climatologists predict that La Nina will yield to neutral conditions over the next three months.
“It’s possible we’ll end up having a remarkably cold winter. It’s not out of the realm of possibility,” Bond said.
Below-average temperatures would be a big change from November. Based on records dating back to 1885, Washington had its warmest November ever, according to the federal National Centers for Environmental Education.
The Climate Prediction Center’s new three-month outlook also predicts below-average temperatures in the Idaho panhandle. The odds are equal for above- or below-normal temperatures in the rest of Idaho, Oregon and Northern California.
Above-average precipitation is forecast for Oregon and Idaho. The odds are 50-50 in Northern California.