US Pacific Northwest hydropower trend below normal on weak snowpack

The hydropower generation outlook across the US Pacific Northwest remains below normal despite an early January cold snap and December precipitation 113% above normal.

"This water year has been mostly drier and warmer than normal," Amy Burke, a hydrologist with the Northwest River Forecast Center, said during the Feb. 1 NWRFC water supply briefing. "Snowpack has been lower than normal, scraping record levels."

The next 10 days are expected to bring lower temperatures and more precipitation to the area, although at levels below normal, Burke added.

"Overall, it's been warmer this year, which has not been great for snowpack building," Burke said. "We hope these temperatures will cool enough to give us some snowpack building."

Snowpack usually peaks in April so the region could still catch up, "but every day we don't catch up, we fall further behind," Burke added.

Below normal

The Washington state Department of Ecology issued a notice Feb. 1 that the July drought declaration is still in effect. Despite an early January cold snap, the water supply outlook for much of the state can be characterized by two words: "below normal," the Department of Ecology said.

"Even folks who are not in a declared drought area right now, should begin preparing for a dry spring," the Department of Ecology's statewide drought lead Caroline Mellor said in a Feb. 1 statement.

October through December -- the first quarter of the water year -- is tied with 1933 as the sixth driest in Washington history, according to the Department of Ecology. December 2023 was the third warmest December on record for Washington state.

"Statewide precipitation was 113% of normal for December, but warm temperatures resulted in much of it falling as rain instead of snow, leaving the state with much below normal snowpack," the Department of Ecology said. "Snowpack is important because much of the state's water is stored as snow as opposed to behind dams. A poor snowpack means less water is available for people, farms and fish in the warm spring and summer months, when it's most needed."

Conditions at The Dalles

Conditions at The Dalles Dam, located on the Columbia River on the Oregon-Washington state border, serve as the barometer for hydro conditions in the region. Less hydro generation in the Pacific Northwest translates to less generation available for exports to neighboring regions.

The water supply forecast at The Dalles Dam is currently at 79% of normal for the April-September forecast period, two percentage points lower than a year ago, but two points higher than a month ago, according to Northwest River Forecast Center data.

Inflows into The Dalles Dam averaged about 108,420 cubic feet per second in January, down almost 14% month on month and a decrease of 29.7% from the average of the previous three years, according to data from the US Army Corps of Engineers. The Dalles Dam is located on the Columbia River on the Oregon-Washington state border.

The NWRFC is expecting runoff at The Dalles to be the 16th lowest year on record, Burke said.

"All told, we're not predicting a big change at The Dalles," Burke said.

Power forwards

The below normal forecast at The Dalles is driving up Pacific Northwest summer power forwards.

Mid-C on-peak June averaged about $70.25/MWh last month, 22% higher than its 2023 counterpart a year ago and 129% above the average of the previous five years' packages, according to data from Platts, part of S&P Global Commodity Insights.

July and August packages traded below year-ago packages until midmonth when the year-ago packages started decreasing.

Mid-C on-peak July averaged roughly $146.75/MWh last month, 7% higher compared to the 2023 package a year ago and 112% above the average of the previous five years' packages, according to Platts data. Likewise, on-peak August averaged around $199.75/MWh last month, 1% higher than the 2023 package and nearly 96% above the average of the previous five years' packages.