Monday, July 15, 2019

Wait, how can there be a drought when it’s raining?

While recent rain is helping many parts of the state, more than a
few scattered showers are needed to fix Washington's drought.
For the past few months, Washington’s weather has been all over the map.

Residents of Spokane and the south east experienced a relatively damp spring, while much of western and central Washington have seen warmer than normal temperatures and low precipitation since April.

And for most of the summer, the usually fire-resistant west side has had a higher risk of wildfires relative to historical norms than has most of Eastern Washington, according to the National Interagency Fire Center.

As of July 11, the U.S. Drought Monitor still shows abnormally dry to severe drought conditions in all but the southeast corner of our state. Five percent of the state’s rivers are at record low, and many locations in western and north central Washington are expecting between 50 and 75 percent of normal stream flow through September.

So what does this all mean when more than half the state is in a declared drought emergency?

Jeff Marti, Ecology’s Water Resources Program drought coordinator, says recent precipitation has been a welcome change, but it hasn’t made up the deficit caused by warmer than usual conditions and a lack of snow pack.

“Over the last few days, some parts of the state have gotten some good shots of rain, and some places, like the Olympic Peninsula, have really needed it," Marti said. "Some rivers have rebounded nicely, but about a quarter of our rivers are still experiencing flows much below normal. It will take continuing rainfall to make that more than a temporary rebound. Our lowest flow season is still ahead.”

Conditions by region


While cooler weather and some rain has bumped up flows that supply irrigation water and support important fish migration in Central Washington, water supply remains in flux. Low reservoir levels in the Yakima Basin – the 7th lowest storage volume in 44 years – mean farmers must remain vigilant and fish managers on alert.

From arid areas to sudden downpours, weather patterns east of the Columbia River have meanwhile been wide ranging. The northeast portions of Pend Oreille and Stevens counties are in severe drought, while the east side’s midsection has seen thunderstorms and flash flood warnings several times over the past few weeks.

Crop damage from heavy rains was reported in Okanogan and Ferry counties, although NOAA’s National Weather Service shows total regional precipitation hovering just under average for the past month.

Conditions in the southeast have mirrored the majority of the U.S., and are wetter than in past years. Walla Walla basin water users have seen some low flows, but that’s mainly due to normal demand across the border in Oregon.

Taken as a whole, Washington’s lingering dehydration – the 13th driest July-June period ever recorded in the state – stands in stark contrast to the rest of the country. According to NOAA, the continental U.S. had its wettest 12 months on record, even as the Pacific Northwest became more parched. And with much of the summer yet to come, resolving this drought will require more than scattered showers.
Washington precipitation departure from average (inches), from July 1-15, 2019. Image courtesy of NOAA.

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