Commonwealth Journal

September 25, 2012

'Neat’ cloud formations are followed by storms

By BILL MARDIS, Editor Emeritus
Commonwealth Journal

Somerset —  

The noontime sky was swirled in restless meringue yesterday as menacing lightning, heavy rain  and hail pounded downtown Somerset.
Clouds overhead were unusual, almost weird. The sky was a swirl of light and dark. Someone said it looked like elongated Swiss cheese.
The storm approached from the northwest as a wavy, almost black wall cloud, extending halfway across the horizon. Once overhead, a light show developed. Lightning flashed and thunder rolled from the churning sky, a scenario almost scary. Marble-size hail sent downtowners rushing for cover.
Pete Geogerian, meteorologist at the National Weather Service in Jackson, said no warnings were issued because of the storm. He called the cloud formations “neat” and said it was the result of temperatures in the 50s and 60s with stable air near the surface and unstable air above. Thunderstorms with rain falling through the interface between the stable and unstable air created what he called stratocumulus clouds.
Stratocumulus clouds belong to a class of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, normally below 8,000 ft. Weak convective currents create shallow cloud layers because drier, stable air above the instability prevents continued vertical development. Normally, there is very little precipitation with this type of cloud development, but yesterday was an exception.
The stormy weather followed nearly a week of near record cold for this early in the year. Frost was reported on Wednesday, September 19; Sunday, September 23; and Monday, September 24.
The earliest frost in this area since 1950 was a 36-degree reading September 14, 1964, according to the National Weather Service. Temperature dropped to 32 degrees on September 27, 1991 and to 28 degrees on October 3, 1974.