I know we don't get strong tornadoes here, but with our cool weather, how do we get ANY?!
Tornadoes don't occur often in Washington state, and even less frequently in western Washington. They are most likely to develop west of the Cascades either during the spring or late autumn months. Tornadoes that do develop here are weak because our thunderstorms are weak. The typical pattern of cool, moist ocean air prevents the sharp cooling with increasing altitude (what we call the lapse rate) that leads to an unstable air mass. Such instability allows rising air (carrying moisture) to keep rising and build large thundershowers. East of the Rockies, thunderstorms can easily top 40,000 or 50,000 feet. In Washington, it's unusual for them to exceed 25,000 feet. But because we do get thunderstorms, even if weak and wind shear (the change in wind speed and/or direction with altitude) we can get tornadoes.