Weather Blog

Sequim asks: Does this look like a stormy November day to you?

Sequim asks: Does this look like a stormy November day to you?
Photo: David Britton

The Olympic Rain Shadow strikes again -- only this time, it was pretty dramatic!

As a warm front moved into Western Washington Wednesday morning, most of the region was covered in a moderate November rain.

But not part of the Olympic Peninsula, where the Olympic Mountains turned into one of the world's largest umbrellas once again.

That bright, colorful photo above was taken at 3 p.m. by David Britton of about 4 miles east of Discovery Bay. Yes -- Wednesday at 3 p.m.

Want to know what it looked like in Seattle from the Univ. of Washington campus at the same time?

Seattle and Discovery Bay are not all that far apart -- about 35-40 miles as the crow flies. I've also marked Keystone, WA (top blue pin there.) You'll see why in a second.

View Rain Shadow in a larger map

KOMO News photographer Peter Mongillo was sent up to the Keystone ferry dock on Whidbey Island to get wind video for the evening newscast. But he also managed to capture the rain shadow in action on video. This too was Wednesday afternoon:

And here is a dramatic visible satellite photo, also taken at 3 p.m. Note the impressive clear spot over Sequim:

Air coming off the Pacific Ocean slammed into the southwestern side of the mountains, causing lift and in essence "wringing out" the moisture. Then as this drier air came down the northeastern side of the mountains, it sank and dried out further, creating this amazing dry spot on the landscape.

Sure enough, the rain gauge at Sea-Tac Airport had reported 0.31" of rain through 6 p.m. on Wednesday while Sequim reported zero rain. Just more proof as to how Sequim can have a lower average annual rainfall (about 15-18") than Flagstaff, Arizona!

(Want to know more about the Olympic Rain Shadow and how it forms? Check out our Weather FAQ entry. And you can get more cool facts and timely updates about Seattle and Northwest weather by following Scott on Twitter @ScottSKOMO and on Facebook at "Scott Sistek KOMO".)

P.S. Thursday morning update: Once the front passed and the wind shifted overnight, the rain shadow disappeared and Sequim actually got a good dose of rain. A city weather station recorded 0.20" Wednesday night into Thursday morning - about 2 percent of their average annual rainfall!