PORTLAND, Ore. – While much of the nation is basking in a mild, tranquil weekend, forecasters are busy in the Pacific Northwest with an autumn storm that is bringing a rare risk of severe weather to the Oregon coast, with even a small risk of weak tornadoes.

A frontal boundary is racing in off the Pacific Ocean, with its eyes on the Oregon coast later Sunday. The storm system will bring widespread showers and scattered thunderstorms Sunday afternoon with gusty winds of 30-40 mph.

In addition, atmospheric conditions are favorable for creating some rotation, giving a risk of a waterspout or weak tornado along the Oregon coast or even into the Portland and Vancouver, Washington area late Sunday into Sunday night, according to the NWS in Portland.

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“Cannot rule out a waterspout or weak tornado at the coast late Sunday into Sunday night either as wind profile becomes more favorable for rotation,” NWS Portland forecasters said.

NOAA’s Storm Prediction Center has painted the area in a Level 1 threat on their 5-point severe weather risk scale, with a small percentage chance of an isolated tornado.  

While Level 1 severe weather risks are fairly common across much of the nation during the year, they are rare in the coastal Pacific Northwest, where the cool, marine air inhibits severe weather.

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The severe weather risk holds into Monday, with chances of weak tornadoes or waterspouts bumping up even a little higher with even more favorable ingredients in place for stronger storms and weak rotation.  

“While this (forecast) may sound scary to some, please keep in mind the over 99% of the population will not see or experience a tornado even if one does develop somewhere,” NWS Portland forecasters wrote in their Sunday morning weather discussion. “That being said, people should at least ensure they have a way to receive NWS warnings just in case. It is also worth securing any loose outdoor objects that may easily blow away in the wind.”

Oregon only sees a few tornadoes anywhere in the state each year, and they are typically weak, rating an EF-0 or 1. The state has never had a deadly tornado, though six died in April 1972 when an EF-3 tornado struck just across the Columbia River in Vancouver.

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Wind Advisories are also in effect for the greater Portland and Vancouver area as the main center of the storm moves in on Monday, with gusts to 45 mph possible.