August 7, 2015

Washington state climatologist provides weekly drought updates

This year’s pathetic snow season wasn’t just a problem for skiers. Now that it’s summer, salmon are struggling because there’s not enough snowmelt to feed streams, and water managers are worried by lack of snowpack or summer rains to feed water supplies until the fall.

When Gov. Jay Inslee first declared a drought in April, the Department of Ecology funded the office of the Washington State Climatologist at the University of Washington to produce weekly updates on the current conditions. These reports, which come out every Thursday, have tracked a changing drought situation.

“We had normal precipitation through the winter, but it was falling as rain rather than snow because the temperatures were so warm,” said Karin Bumbaco, the assistant state climatologist. “It didn’t look like the droughts that we’d seen before.”

That so-called “snow drought” was followed by a prolonged spell of warm, dry weather.

“This spring was warmer than we’d expected, and we saw that continue into the summer — July was the warmest month ever in Seattle,” Bumbaco said. “The situation has morphed more into what you’d expect a standard meteorological drought to look like, with lack of precipitation and extremely warm temperatures.”

Each week since mid-April, Bumbaco has prepared a report that includes the temperature, precipitation and streamflow data for the past week and month, and information from the national U.S. Drought Monitor. About 65 percent of the state’s rivers and streams are now in the lowest 10 percent of flow rates compared to previous readings at the same time of year.

The second page initially focused on weather in the regions of declared drought. Now that the drought is statewide, that page is a rotating discussion of conditions in different regions, or the drought’s effects on things like salmon runs, agriculture or hops harvests.

The most recent report, for example, looks at river temperatures and the effects on salmon runs and fish hatcheries, a water district’s restriction on fruit-tree irrigation in the Wenatchee region, and soil moisture levels on the Olympic Peninsula, where a fire is burning in a residential area near Shelton.

The third page offers a look ahead. It includes forecasts for the next eight to 14 days and further out, and will occasionally look at whether the current conditions match earlier forecasts. That page is written by Nick Bond, the state climatologist and a meteorologist with the UW’s Joint Institute for the Study of the Atmosphere and Ocean. Here there is some good news, with precipitation on the horizon.

The original audience for the weekly report was mostly state agencies and water managers, Bumbaco said, but interest from the general public has been increasing with the continuing drought.

“We’ve gotten positive feedback on the newsletter,” said Jeff Marti, drought coordinator at the state Department of Ecology. “The climate office does a great job of condensing recent and forecasted climate data into a simple format that we can readily share with members of the public.”

The team plans to continue producing the reports through the end of September, or longer if the fall rains come later than usual. After that, the reports will become part of the state climatologist’s archives.

“I think it’s going to be a great resource for looking back in our next drought,” Bumbaco said. “It can help us to see how the drought of 2015 played out, and what its impacts were.”

The state climatologist’s office also produces a monthly newsletter that discusses various weather topics, along with a summary of the past month’s conditions and any notable events or trends.

“We hope the one-stop shopping represented by the weekly drought report is proving to be informative and interesting to a wide audience,” Bond said.

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For more information, contact Bumbaco at 206-543-3145 or kbumbaco@uw.edu, Bond at nab3met@uw.edu or 206-526-6459 and Marti at jeff.marti@ecy.wa.gov or 360-407-6627.