National Weather Service United States Department of Commerce

Severe Weather and Heavy Rain from the Ohio Valley to the Mid-Atlantic; Heat Persists in the South-Central U.S.

Widespread strong thunderstorms with damaging winds and locally heavy rain are expected across portions of the Ohio Valley into southern Mid-Atlantic and Carolinas. Rounds of strong thunderstorms are expected to develop across the northern and central Plains. Sweltering heat remains most persistent across the South-Central Plains and Lower/Middle Mississippi Valley through next week. Read More >

Shelf clouds are often associated with squall lines, and many times they are reported as wall clouds, funnel clouds, or rotation. Below is a brief review of what a shelf cloud, wall cloud, and funnel cloud look like. Remember, that the main threat with any squall line is severe damaging winds associated with the shelf cloud, although brief spin-up tornadoes can occur. Often times, these tornadoes are rain-wrapped and short-lived.

A shelf cloud will usually be associated with a solid line of storms. The wind will come first with rain following behind it. It may appear to rotate on a horizontal axis.

 

Crawford County wall cloud

Wall clouds will rotate on a vertical axis, sometimes strongly. The wall cloud is much smaller and more compact than a shelf cloud and is usually under a rain free cloud base.

 

Scud clouds are often mistakenly called wall clouds or funnel clouds. In reality, these are just rising clouds due to increased low level relative humidity. They will not rotate and will rise slowly.