Cold air damming occurs when a shallow cold air mass is funneled across the earth's surface due to topography. Cold air is dense and stable and thus it resists flowing over elevated terrain unless the cold air mass is deep or the forward momentum of the air mass is strong. Below is a cold air damming episode that occurred on January 26, 2004. This is a sounding from Atlanta showing the contrast of air masses in the vertical (32 F at surface while 54 F at 900 mb).  |