Cold Air Damming (CAD) also know as a wedge. This feature builds in at the surface when a high pressure in the Mid-Atlantic or Northeast exceeds the strength of 1030mb, usually occurring throughout most of Western Virginia, Western North Carolina, some of Upstate South Carolina, and Northeast Georgia. The feature is relatively dominant when a system moves in, when it is built in.

There are two types of CAD:

Classical, which is when a high pressure builds in the Northeast or Southern Canada as a storm moves through.

In- Situ, which is where a high pressure moves out of the Mid-Atlantic or Northeast, then moves out to sea once a storm system moves in. The cold air is still funneled in though the high is well off shore, or is lingering due to cloud cover.

CAD often is what results in ice storms throughout the CAD region. In addition, CAD also is a buffer to severe weather events when present, negating the threat down to a minimal level.

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