National Weather Service United States Department of Commerce

Frigid Airmass to Bring Significantly Colder Temperatures; Snow Continues Downwind of the Great Lakes

A frigid cold airmass will bring significantly colder weather across the eastern two thirds of the country early this week. Record low temperatures are expected in the Southeast by Tuesday morning. Moderate to heavy lake effect snow will continue downwind of the Great Lakes through Monday. Several inches of snow accumulation is expected, including in portions of the Chicago Metro Read More >

Automatically generated image showing areas of convective available potential energy.

 

Thumbnail of an automatically generated image showing areas of convective available potential energy. Thumbnail of an automatically generated image showing areas of convective available potential energy. Thumbnail of an automatically generated image showing areas of convective available potential energy.
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CAPE 

This is a surface based Convective Available Potential Energy (CAPE) measurement only.  In the cool season, elevated instability may be much higher than surface based cape.

On average, CAPE of 1000 J/Kg is usually sufficient for strong to severe storms. CAPE of 3,000 to 4,000 J/Kg or higher is usually a signal of a very volatile atmosphere that could produce severe storms if other environmental parameters are in place.

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