Even with warmer weather in the forecast, winter is hanging tough throughout the Pacific Northwest.
Persistent cool temperatures and drier than normal conditions factor into the drought outlook for the region in 2023, speakers said at the monthly drought and climate outlook meeting on Monday.
Washington state climatologist Nick Bond said it has been considerably cooler than normal from late March through mid-April, a continuation of colder-than-normal conditions seen throughout the winter months in the interior Pacific Northwest.
Impacts to snowpack, water availability and soil moisture pose some uncertainties for what the region can expect for drought this year, he said.
The seasonal outlook from the Climate Prediction Center shows drought persisting throughout Oregon and northern Idaho through July, with drought development likely in Washington.
Water availability
Storage levels in the Yakima, Columbia and Upper Snake River basins were in decent, if not great, shape as of Thursday, Bond said. There may be some restrictions on junior water rights holders in the Yakima Basin this summer, he said.
Bond said snowpack is also in good shape throughout the region, especially in southern Idaho and much of Oregon and will help in filling those reservoirs.
Hydrologist Geoffrey Walters with the Northwest River Forecast Center said snowpack levels are above normal, while soil conditions are drier than normal.
“Those two factors of snowpack and soil are competing against each other,” Walters said.
Bond said there was a dry end to summer and fall in 2022. The area’s soils didn’t get the burst of rainfall that is typical before temperatures drop below freezing, he said.
“Right now, we’re coming out of the winter season with really dry subsoil moisture contents,” Bond said.
That means the soil will soak up melting snowpack before there’s any substantial runoff, he said.
“How much of an effect that’s going to make is going to vary from place to place,” Bond said. “Ultimately, we’re just going to have to wait and see how that dry fall is going to play out in terms of the eventual stream flows this spring and early summer.”
Walters also predicted a delay for runoff this year.
“April is typically thought of as the beginning of snowmelt season, but unfortunately this isn’t a typical year,” he said.
Cooler temperatures mean denser snowpack at this point in the year and a delay in the onset of melting, Walters said.
With the cooler temperatures, the snowpack melting has not yet begun in earnest, Bond agreed.
Potential for drought
The problem areas for drought look to be northern Idaho, northwest Montana and especially eastern Oregon, Bond said.
The U.S. Seasonal Drought Outlook dated April 20 shows drought persisting in much of Oregon and northern Idaho through July.
There is potential for drought in central and eastern Washington, according to the outlook.
Bond said there’s a consensus that summer will be on the warm side. Though there is warmer weather in the forecast for the next week or so, temperatures will cool off again before summer sets in, he said.
“I think we’ll have to wait and see how the late spring turns out, but because of the way many of the recent summers have been and what the models are showing, I think we can also expect this summer to be warmer than normal,” Bond said. “Therefore, there’s the potential for some drought concerns to emerge, but it does not look like it’s necessarily going to be anything severe.”
Wildfire season impacts
Walters said the higher levels of snowpack and delayed runoff caused by cool temperatures this year may be a positive heading into wildfire season.
The longer that snowpack remains, the more it will help reduce potential fire conditions, he said.
