New Study Shows Increase In Stormy Weather In Western Washington

Mar 20, 2013

Climate change will affect different regions of the country in different ways. In the Southwest it may get warmer and drier. In the Northwest, however, climate models predict it getting warmer and wetter.


A stormy scene on the Dungeness Spit in Washington state. Climate researchers say rainfall data suggests it's getting stormier on the Olympic Peninsula.
Credit masmediaspace / Flickr

  That means less snow and more rain. It could also mean more stormy weather. Ashley Ahearn from our EarthFix desk reports on a new study in the journal Nature Climate Change.

The Northwest is famous for its steady gray drizzle. But for violent storms and down pours? Not so much. That might be changing.

Scientists at Washington University in St. Louis looked at rainfall data gathered at 13 sites around the U.S. over the last 70 years or so.

But they weren’t just looking at how much rain falls. They were looking at how much rain falls …per hour. That level of detail in the data gave them a measure of how “stormy” it is.

One of the 13 sample sites was on the Olympic Peninsula. Jonathan Katz is a professor of Physics at Washington University and a co-author of the paper.

Katz: “So here we have some evidence, at least in one place, that it is getting stormier. There really appears to be a systematic increase in the amount of rain that comes in intense bursts as opposed to a very steady drizzle.”

The study did not find a significant increase in stormy weather at the other 12 test sites. Katz says this could be because it rains steadily on the Olympic Peninsula, as opposed to other parts of the country that are prone to thunderstorms and hurricanes. An increase in short bursts of intense precipitation would be more noticeable here.

Eric Salathé is a senior researcher with the University of Washington’s Climate Impacts Group. He says this study adds a piece of information to the broader climate predictions for the Northwest.

Salathé: “I would look at this study and say, with climate change we should be concerned about heavier precipitation.”

Of course, one sample site does not equate to a region-wide prediction for rainfall patterns. Climate experts in the Northwest say more detailed sampling and analysis needs to be done, but heavier precipitation could add to the coming challenges of flood management and stormwater runoff.

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