Watch: Cumulus clouds bubble over Cascades in unstable atmosphere

It was a pleasant, sunny Monday in the lowlands, but up in the northern Cascades, the skies were quite a bit more turbulent.

A weak trough of low pressure slid over the region bringing a little bit of cooler air aloft.  That creates instability in the atmosphere and soon the day's heat used the mountains as a springboard to shoot some towering cumulus clouds over the ridgetops.

Kevin Freitas was watching the show and took this amazing time lapse video of the clouds' development:

The show was visible by satellite images as well:

Unfortunately some of those cumulus clouds graduated into thunderstorms that brought lightning to north-central Washington, triggering at least one wildfire along the Colville Indian Reservation, according to the Northwest Interagency Coordination Center.