Re: Why is lightning uncommon in the winter

ID=858567008.Es

Dear Brad:

The reason that lightning is uncommon in winter has to do with the source of lightning.
Lightning is produced by rapid convection (lift) within clouds. When you have lift, ice
particles in the clouds rub together, producing a static charge. The more energetically
they rub together, the greater the charge that builds up.

During wintertime, lift in the atmosphere is less energetic. This is because the difference in
density (due to either temperature or humidity differences) between the two air masses that create
a front (where wintertime precipitation usually originates) is not as great as during summertime.
Since the lift is usually not as rapid, less static charges build up and lightning is less likely to occur in wintertime.

In summer, frontal storms and thermal (AKA: airmass) storms ("afternoon showers and
thunderstorms") are BOTH energetic enough to often cause lightning. Airmass thunderstorms are
rare in most of the U.S. during wintertime. So, overall, lightning is much more common in
the summer.

If you have further questions about this topic, please feel free to contact me by e-mail.

Clay Harris
Middle Tennessee State University
cdharris@frank.mtsu.edu