National Weather Service United States Department of Commerce

Major Winter Storm to Impact the Mid-Atlantic and Northeast; Inclement Weather in the Pacific Northwest

A major winter storm is expected to bring heavy snow, strong winds, and coastal flooding across the Mid-Atlantic and Northeast that may cause impossible travel conditions and power outages. Blizzard conditions are possible along the Northeastern Seaboard. Wet weather and strong winds return to the Pacific Northwest and north-central California. 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.