From now through the end of September, drought is likely to develop or persist throughout most of Washington and into northwestern Oregon and the Idaho panhandle, according to a new seasonal drought outlook by NOAA's Climate Prediction Center.
Portions of the Snake River in Idaho--which have been getting above-normal precipitation--are well outside the predicted drought areas.
Climate experts discussed the new forecast during a June 24 NOAA webinar.
John Abatzoglou, associate professor of geography at the University of Idaho, noted that most of Oregon, Idaho and Montana are not currently experiencing drought, nor are they expected to this summer. The locations where drought is expected are generally the same areas that have seen lower than normal precipitation over the last two months.
Washington's Olympic Peninsula and the northwestern portions of Puget Sound are already classified as severe drought areas, with moderate drought stretching along the coast into northeast Oregon, east into central Washington, and across the Canadian border through Washington, Idaho and the tip of northwest Montana, Abatzoglou said.
He noted that the drought doesn't stop at the Canadian border, but extends throughout a huge area encompassing southeast Alaska and parts of British Columbia and Alberta.
Many of the areas that are climatologically wet in normal years are now experiencing drought, while some of the drier areas have seen above-normal precipitation. "This is quite reflective of what we see during El Ninos," Abatzoglou said.
Troy Lindquist, hydrologist with the National Weather Service in Boise, said El Nino is expected to continue through this summer and fall, and possibly into winter.
Despite some cooler-than-normal periods, temperatures overall this year have been warmer than normal, he said. Summertime heat is expected to arrive in early July. "The outlook pretty strongly favors above-normal temperatures, and a slight lean toward below-normal precipitation," he said. That means areas that are already in drought are likely to get worse.
Those conditions are expected to produce a greater chance for significant wildland fire potential along the Canadian border, western Washington and western Oregon, Lindquist said.
Despite the drought outlook, water supply overall looks favorable in many areas, he added. The water supply in northwestern Washington and along the Canadian border ranges from 55 to 85 percent of normal, while many rivers and streams in Oregon and Idaho range from 90 to 193 percent of normal.