John Wheeler: The weather in winter is sometimes much warmer a few hundred feet up
Temperature inversions, when a layer of warm air aloft covers cooler air below, are much more common during winter.
FARGO — The layer of air comprising the lower few hundred feet above the ground is known meteorologically as the "boundary layer." It is this lower layer of the atmosphere that is most affected by the interaction between sunshine and the Earth's surface. In winter, when the ground is covered in snow, a great deal of the sunlight is reflected back into space, allowing the boundary layer to get and stay cool. Temperature inversions, when a layer of warm air aloft covers cooler air below, are much more common during winter.
During an inversion, the warmer air above can have completely different characteristics than the air at the ground, including different wind speed and direction. In some cases, a persistent fog can form under the inversion and last for days, while just a few hundred feet up, the weather is sunny and much warmer than at the ground.