While higher terrain stays relatively mild, low-lying spots can become significantly colder, sometimes cold enough for frost ...

The winds enclose a large pool of extremely cold air, according to the NOAA. Here is a much simpler way to visualize the Arctic polar vortex: In a simple scenario, with little weather occurring ...

Ever noticed how valleys and low-lying areas feel chillier on calm, clear nights? That’s cold air pooling in action. As the sun sets and the ground loses heat, the air near the surface cools down.