Weather Blog

Friday's thunderstorms show off some amazing clouds

Friday's thunderstorms show off some amazing clouds

The photos looks straight out of Kansas, but no, they were taken here in the good ol' Puget Sound region.

Some thunderstorms formed off the Cascade Mountains early Friday afternoon and then winds in the upper atmosphere steered the storms southwest into the Seattle-Tacoma-Everett areas.

Reports of thunder and lightning were scattered across the region, with also reports of 1/4" hail and bursts of gusty winds in the storm's downdrafts.

The photo above and video below was taken by Jonathan Cooper, who went up to Glacier Peak High School in Snohomish during the storm (around 5 p.m.) to chase some photos. What you're seeing is a "shelf cloud" caused by the outflow from the storm's downdrafts.



We also had a few photos of Mammatus clouds -- also signs of instability in a good thunderstorm.



Both clouds are pretty rare sights around here, but sure pretty to look at!

The storm, as I mentioned, was also a windy one.  Thunderstorms can produce a strong downdraft as cold air and rain rush out of the storm's base, creating a line of strong winds as they do so.

Power outages were reported in at least Silver Lake, Bothell, Kirkland, Redmond, and Bellevue as a gust of wind blew out from the storm. There were also several reports of tree branches -- or in some cases, the entire tree! -- across northern King and southern Snohomish County.  Wind speeds that I could find from spots in near the storm were in the 35-40 mph range but it wouldn't surprise me to hear of higher gusts.

This video below was taken by Joey Sipos who was near Redmond/Sammamish when the storm hit. "A huge tree branch almost hit my car so I pulled over and started filming!" he wrote to me.

Thunderstorms are all gone now. Enjoy a much calmer holiday weekend!