National Weather Service United States Department of Commerce

Heavy Rain in the Southeast; Wintry Mix from the Plains through the Ohio Valley

A storm system will bring a number impacts to the central and eastern US. Heavy rain and thunderstorms are expected in the Gulf Coast and Deep South. Further north, a wintry mix may produce a glaze of ice from the Ozarks/Mid-South east through the Ohio Valley. Accumulating snow is expected from the central Plains east into the Upper Ohio Valley/Lower Great Lakes. Read More >

Wave clouds (or gravity waves): These form when stable air moves over a raised land feature, such as hills or mountains, and is forced upward. Gravity then causes the air to fall back down, and it begins to oscillate, creating that ripple effect. 

 

 

This visible satellite image was taken at 400 pm PDT 9 Sep 2000. The cloud lines oriented north to south are wave clouds. They are the result of west-to-east wind flowing over the Cascade mountains of Washington and the Rocky Mountains of Montana and Alberta.