In winter, especially when there is snow on the ground, air temperature forecasting can become very difficult compared to the rest of the year.
Snow cover often causes the air in the lower few tens of feet to become colder than the air above. This is known as a temperature inversion. Clouds, wind and changing snow cover can all affect the temperature profile, particularly the air near the ground. Snow cover reflects solar rays and also enhances terrestrial radiation (Earth’s rays heading out into space).
Both of these processes cool the air near the ground. Clouds reverse the process of terrestrial radiation, causing the air near the ground to warm up. Wind has the effect of mixing up the air. Depending on the amount of turbulence, windy conditions can disturb the temperature profile, sometimes mixing warmer air from above down to the ground.
It all makes for a complicated forecast.
