SPOKANE — A La Nina is on the way, bringing with it wetter weather later this spring.
That’s the prediction of weatherman Art Douglas, who delivered his long-range forecast Feb. 4 at the Spokane Ag Show. Douglas is a professor emeritus of atmospheric sciences at Creighton University in Omaha, Neb., and is a fixture at the show.
El Nino and La Nina are complex weather patterns that result from variations in the Pacific Ocean’s surface temperatures.
Lower ocean surface temperatures off the West Coast mean a La Nina will develop later in the spring, Douglas said.
“Here in the wheat area, (the forecast is) about normal to above normal precipitation, which is what La Nina would suggest,” he said.
Douglas called for a “warmish” May, with normal to above normal precipitation in the Pacific Northwest.
His summer forecast calls for a warm and dry June and July and a cool and wet August.
In the meantime, the Pacific Northwest has become wetter in the last 30 days, following an El Nino in which the region was “very dry” from April through September, Douglas said.
A high-pressure ridge in Alaska will block Pacific moisture from reaching the West in February, Douglas said.
The pattern will persist into March.
“So it’s going to have an impact on spring weather, but not as bad as it could,” Douglas said.
Winterkill of wheat will be a concern in February and early March, Douglas said.
Through the spring, high pressure ridging in the Pacific and Southwest will favor dry weather elsewhere in the West.
From March through May, Douglas predicts normal temperatures in the Pacific Northwest and slightly drier conditions west of the Cascades.
Douglas said the 2020 forecast appears most similar to the years 1989, 1990, 2008 and 2018.
“Do not go and look at one of those years alone and say, ‘This is what I’m going to have this year,’” he said. “It’s all of these four years together. It’s a blend.”
Warming in the Pacific Ocean over the past five years was due to weakened wind systems and weaker ocean currents. Warming in the Atlantic Ocean is due to enhanced wind systems and ocean currents.
“The two oceans aren’t behaving the same, in fact, they’re the opposite of each other,” Douglas said. “If you believe in global warming, both oceans would have to be behaving the same, and they’re not. These are decadal climate changes we’re dealing with right now, and apparently we’re getting ready to change.”
The forecast should mean a less intense fire season for the Pacific Northwest, which this year will likely end earlier, Douglas said.
Farmers can expect “better early fall moisture and cooler temperatures,” he said.