Science & Environment

State climatologist warns of ‘flash droughts’ as heat wave fries Oregon

By Brian Bull (KLCC)
July 27, 2022 10:01 p.m.

With many parts of Oregon seeing temperatures in the upper 90s and beyond this week, the state climatologist says there’ll be definite intensifying of existing drought conditions.

It’s the first major sustained hot spell of the year, with the sun bearing down on areas already suffering historically dry and arid conditions.


Related: Records fall as Northwest swelters under multiday heat wave

Larry O’Neill is an associate professor at Oregon State University and the state climatologist. He told KLCC that when these kinds of heat waves hit in the middle to near end of summer, there can be formations known as “flash droughts.”

“And what a flash drought is, it’s basically a rapid drying of any remaining moisture in the soil and plants, and just the landscape in general,” explained O’Neill. “And so those conditions can lead to a quick intensification of drought conditions. And so we’re monitoring that very closely right now.”

Most recent drought map for Oregon.

Most recent drought map for Oregon.

U.S. Drought Monitor


O’Neill says areas most susceptible to flash droughts are the foothills of the Cascades, and then areas of Douglas County, namely Roseburg down into Medford.

The roughly weeklong heat wave hitting parts of Oregon could also be one for the record books.

O’Neill says it’s not so much the intensity of the temperatures, as it is the duration that makes these “very interesting times.”

“The fact that it’s forecast to occur over 5 or 6 days and then gradually taper off… if that forecast holds, this’ll be one of the longest heat waves in the Pacific Northwest in our historical record… that amount of drying of the landscape over a weeklong period,” said O’Neill.

“So this may be the second consecutive year where we have a historically significant heat wave in the Pacific Northwest, the likes of which we haven’t seen before.”

The heat wave will also worsen drought conditions and increase the risk of human-caused wildfires. People are advised to hydrate and limit the use of fire or machinery that could produce sparks or heat.

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