What Makes Air Unstable?

Tools

By By Steve Pool

SEATTLE - Don't you love those days where it'll be sunny for 20 minutes, then you scramble for your umbrella as it pours?

Usually in the days following a good-sized storm, we get a rush of colder air moving into the upper levels of the atmosphere. That makes it easier for clouds and storms to form because when pockets of warm air rise from the ground, it'll keep rising farther since it will stay warmer longer relative to the surrounding cold air.

If the air is really unstable (read: really cold air moving in), it can create storm cells with heavy rain with frequent lightning and/or hail. These storms tend to form in the afternoon and evening after the sunshine has had a chance to warm the ground and get the process started.

Your Photos

YouNews Sun halo Sun halo
Sun halo near Orondo, WA over Memorial Day Weekend. Photo by Stephanie Campbell.
YouNews Almost Old Enough!! Almost Old Enough!!
About a week ago I posted 3 pictures of 4 newly hatched Dark-Eyed Oregon Junco chicks. These are the same little ones, 8 days old now. They should fledge by June 1. It's amazing how quickly they grow. A week ago there was tons of room in the nest.
YouNews 70th Annual Memorial Day Service 70th Annual Memorial Day Service
Each year since 1946, the Nisei Veterans Committee has held a Memorial Day Service to honor all who have died in service of their country, especially members of the 442nd Regimental Combat Team, the most highly decorated unit for size and length of service in the history of the US Military, and the Military Intelligence Service, a group credited by General MacArthur's staff with shortening the War in the Pacific by two years