OLYMPIA — Warm water temperatures in the north Pacific Ocean are starting to cool after three years, but their effect on Northwest salmon will persist for another year or two.

“Strange times, but things are looking up, that’s the message,” said Marisa Litz of the Washington Department of Fish and Wildlife.

Litz made her comments on Tuesday at the agency’s annual unveiling of Columbia River, coastal and Puget Sound salmon forecasts. She recently completed her doctorate from Oregon State University in Fisheries Science, focusing on how variable ocean conditions affect growth and survival of young salmon in the Northwest.

Tuesday’s meeting began a six-week process that concludes with the Pacific Fishery Management Council adopting ocean salmon fishing seasons in mid-April.

The “blob,” a huge pool of warm water in the north Pacific Ocean, formed in December 2013, Litz said. Sea surface temperatures were 2 to 4 degrees warmer than normal.

El Nino warm-water conditions peaked in November 2015. A weak La Nina (cooler than normal), occurred in June 2016, she said.

With the warmer ocean water came a low biomass of the type of copepods good for the diet of salmon and a high biomass of southern copepods, which are not as beneficial, she said.

Strange sightings in 2015 and 2016 included tropical fish off Vancouver Island in British Columbia, ocean sunfish in Alaska and huge seabird die-offs in Oregon, Washington and Alaska.

Domoic acid, a natural marine toxin, has — at times — closed some recreational and commercial razor clam fisheries on the West Coast.

Substantial cooling occurred between late October 2016 and Christmas, Litz said.

Currently, the ocean is in a “neutral” condition, neither El Nino or La Nina.

“If we remain in a neutral situation, things should be looking up,” Litz said.

Also helpful for salmon is the average snowpack this winter in the Cascade and Rocky Mountains.

The snowpack was a record-low in 2015 and the run-off was poor in 2016 when an average snowpack was melted early by a warm spring, she said.

Columbia River forecast — A return of 582,600 fall chinook salmon is forecast for 2017. That compares to 641,900 in 2016 and 1.3 million in 2015.

“It’s below recent average returns, but a run size of almost 600,000 is still decent for the Columbia River,” said Ron Roler, Columbia River policy coordinator for the Department of Fish and Wildlife.

The forecast for the popular upriver bright stock of fall chinook is 260,000, compared to 406,600 in 2016 and 919,000 in 2014.

Roler said he is optimistic about the upriver bright stock.

“I expect it to bounce back with good ocean and good outmigration conditions,” he said. “It’s a healthy stock.”

A good return of 158,000 fall chinook to Spring Creek National Fish Hatchery on the Columbia River in eastern Skamania County is forecast. That compares to 44,600 in 2016.

That stock of chinook provides good catches in the ocean and at Buoy 10 in the estuary, but becomes much less desirable as the fish deteriorate when moving up the Columbia River, Roler said.

The Columbia coho forecast of 386,300 compares to the poor return of 259,000 in 2016.

Roler said the forecast is 71 percent of the 10-year average.

Coho releases in the Columbia River have dropped from almost 30 million in the 1970s through 1990s to fewer than 20 million in 2016.

Coho releases in to waters downstream of Bonneville Dam have dropped from 25.8 million in the 1970s to 10.9 million in 2016.

The PFMC will adopt the final ocean fishing season when it meets April 7 to 12 in Sacramento. Fall sport-fishing rules for Buoy 10 and the lower Columbia will be announced at the end of the PFMC process.