It seems that whenever it’s unseasonably warm in Chicago in winter and early spring, it seems that it is always very windy. Why?
Thanks, Mick L., Chicago
You are absolutely correct. By definition, unseasonably warm weather occurs during the colder times of the year, when warmth is confined to the southern states. Strong atmospheric forces are needed to transport the warm air as far north as Chicago, and the best mechanism for doing this is an intense low-pressure center passing north of the city that generates strong-southerly winds. Once the storm system moves east of Chicago, winds shift northwest, and a sharp turn to colder weather follows. If warm air moved into Chicago in winter or spring in a light wind situation, it would trigger a lake breeze that would quickly put a lid on rising temperatures in the city.