What caused all the hail on Wednesday?

Layers of cold vs warm air explains phenomenon

CHICOPEE, Mass. (WWLP) – You may be wondering why we had so much hail Wednesday. There is, of course, a good reason for it.

To simplify things, imagine a cold layer higher up in the sky, where temperatures are below freezing. Then, imagine a warm layer of above-freezing temperatures down closer to the ground.

When a storm brings only rain, it is because that storm formed in the warmer layer, so there is no opportunity for freezing. This happens either when the cold layer begins higher up in the sky, or when storms form lower to the ground.

What happened Wednesday is that the cold layer was lower to the ground than it usually is at this time of year. With updrafts in the thunderstorm, that forced the top part of the storm into the cold layer, where lifted rain could freeze into hail, and fall down to the ground as hailstones.