Gorgeous sunset gave clues to impending thunderstorms

Sunset taken July 12, 2012 from Mukilteo, WA.

Before the thunderstorms stole the spotlight Thursday night and Friday morning, it was the incredible sunset that was the talk of the town Thursday evening.

But those sunsets included a sign that the thunderstorms were close at hand.

The sky was dotted with tiny, puffy cumulus clouds. Those who have been in the Midwest and East Coast know that those little cumulus clouds are a signal that much larger storm clouds are coming.

That's because those little clouds, officially known as "altocumulus castellanus" (ACCAS), are a sign of an unstable atmosphere -- the air "bubbling" to the small clouds that can gradually get larger.

Around here when you see them, it means it's likely muggier than you're used to and you could soon hear some rumbles of thunder. (The clouds were also prevalent on Sunday ahead of the storms that night.)

Thursday night, they just happened to be part of brilliant sunset that had some aid from our wildfire haze imported from Asia.

Here are two videos that show the effect as well, both taken by Greg Johnson of

And here is the video that shows the ACCAS clouds at the start, followed by the thunderstorms a short time later:

And finally, here is another video shot by Kathryn Schipper: