GREENSBORO, N.C. — Many folks across the Piedmont Saturday night heard what they described as "loud booms" that sounded like explosions. The booms were heard in Yadkin, Stokes, Surry, Forsyth, Davie, Rockingham, and Randolph counties.
There are several theories as to what the booms could have been, but none have been confirmed.
WFMY's Ben Smart spoke to Dan Leins with National Weather Service in Raleigh on Sunday, who said there were no significant weather events close by that caused the booms. WFMY's Meteorologist Christian Morgan confirmed that to be true, however, there was a piece of the weather setup Saturday night that could have influenced how loud the sound was and how many people heard it. It's called a temperature inversion.
According to WFMY's Christian Morgan, there was a strong temperature inversion Saturday night, meaning there was a layer of warm air above the surface, trapping in a colder layer of air near the ground.
This isn't uncommon, but typically temperatures decreases with altitude. When an inversion happens, the air actually warms and temperatures increase with altitude for several layers of the atmosphere before it starts to cool again. This is the inversion. It's very typical at night because of the ground losing solar radiation, or it's heating from the sun. Because the ground isn't taking on anymore heat, it starts to release that heat, cooling the ground but warming the layer of air directly above it, which is how the inversion sets up.
Trapped in a layer of cold air, sound waves continually bounce back and forth against the ground and the warm layer of air, making them echo loudly and travel farther. Anything like an explosion, thunder, a car crash, or these booms that were heard, can be heard for many miles, and quite loudly, too.
