ASHEVILLE, N.C. (WLOS) — When cold fronts move through western North Carolina, the setup can create one of the most common winter patterns: Northwest flow snow.
Northwest flow snow happens when cold, moist air blows in from the northwest behind a front. The air behind the front brings polar air from Canada, the Midwest and the Great Lakes. As that air hits the mountains, it’s forced upward. The air cools further and forms clouds and snow showers.
Northwestern-facing slopes tend to receive the most snow during these events as the air cools on the northwestern sides. The highest snow accumulations are typically along the Tennessee and North Carolina border, where that upslope lift is strongest. But as the air drops into the valleys, like around Asheville, it warms and dries out. Some mountain towns can get several inches, while the valleys may only see flurries due to our mountain topography…