
Tornadoes
For information on tornado strength and damage, checkout this tornado infographic by Weather Underground.
Shown here washing over the sky and rolling up to the Seattle shore, roll clouds are a rare treat usually awarded to those living in coastal areas. When a large pool of cooler, sinking air near the ground sweeps under moister, warmer air, the contrast can give the air a spin along a long horizontal axis, much like a rolling pin. The cool air may come from a sea breeze or a decaying thunderstorm. A roll cloud is often detached from all other nearby clouds, giving it extra prominence.
Click on the posters below to learn more about the conditions and to download free high-res print and postcard files!