Why is it not typical to have thunderstorms in winter months?
There are several conditions required to produce a thunderstorm. One is shear, the other is instability. 'Shear' is a change in wind speed or direction with altitude. We do still see that during the winter. Instability comes from a strong decrease in temperature with altitude...rather warm temperatures near the ground, cold temperature farther up in the atmosphere. During the winter months, there's less sun to heat the ground...and the cooler air aloft holds less moisture. That means less instability...and a reduced chance of thunderstorms.