Our position east of the Appalachian Mountains sometimes results in a unique setup that can cause our weather to vary significantly.
Cold Air Damming, or the wedge as many call it is when cold air gets wedged up against the mountains. Clockwise flow around an area of high pressure to our north results in winds low level winds with a NE/E component that push up against the east side of the mountain range.
At the same time, moisture from the south overruns this cool air allowing for clouds to form. Drizzle or light rain can also occur in a wedge setup.
The wedge is strongest across central VA and NC – but even in coastal VA and NC, we can see some influence of the wedge.
Wedge setups result in cloudy, damp, dreary days. They can be a pain to forecast as models sometimes under estimate the amount of cold air associated with them, or forecast the wedge to break sooner than it actually does.
Our region isn’t the only spot that sees the wedge or cold air damming. It can also occur on the eastern side of the Colorado Rockies.
