Western Oregon and southwest Washington have deteriorated from moderate to “severe drought” in the past week, the U.S. Drought Monitor reported Thursday.
A severe drought that already had covered much of Eastern Oregon crossed over the Cascades into the Willamette Valley and as far south as Douglas County. The percentage of the state in severe drought more than doubled to 55 percent from 25 percent. The southwest corner of Washington, making up 6 percent of the state, moved from moderate to severe drought. It’s the first time any part of Washington has been in a severe drought since late 2015.
“What we really need is to see some recovery in soil moisture and streams flows, and the long-term forecast is hot and dry,” said Kathie Dello, associate director of the Oregon Climate Change Research Institute.
The weekly drought report, a snapshot of current conditions, continues a summer-long trend toward drought developing in the Northwest. The USDA reported this week that while some crops were thriving in the heat, others were showing signs of stress.
The USDA, National Oceanic and Atmospheric Administration, and the University of Nebraska collaborate on the Drought Monitor. The four stages of drought range from moderate to exceptional.
Some 83 percent of Oregon and 29 percent of Washington are at least in moderate drought. Most areas not in drought are “abnormally dry,” according to the monitor.
Two months ago, Washington was on the wet side, as was Western Oregon. The National Weather Service’s Climate Prediction Center says the odds favor above-average temperatures and below-normal precipitation to continue for the rest of the summer.
Washington State Assistant Climatologist Karin Bumbaco said periodic summer rains have been absent, while temperatures have been high.
“It’s looking like it’ll get worse before it gets better,” she said.
In Idaho and California, conditions have been steady. Some 6 percent of Idaho is in a moderate drought, while drought conditions range from moderate to extreme over 44 percent of California.
Washington State Climatologist Nick Bond said he expects August to be warmer than average, but for temperatures to be more moderate than in July.
“I don’t think there will be the sustained heat as it has been in July,” he said.
Sea-surface temperatures along the equator in the Pacific Ocean have been warming up. There is a 70 percent an El Nino will form next winter, according to the Climate Prediction Center. Northwest winters are generally warm during an El Nino.
La Nina conditions, a cooling of the ocean associated with robust snowpacks, have prevailed the past two winters. A third straight La Nina can probably be ruled out, Bond said.
“My feeling is that it’s more likely than not to get into the weak to moderate El Nino category,” he said.
In a weekly crop report, the USDA said that irrigated crops in Oregon were doing fine, but unirrigated pastures were drying up. In Washington, unusually high temperatures around Puget Sound were stressing crops. “All producers with access to irrigation were irrigating,” according to the USDA.