UT Geologist Says Big Cities Make Their Own Weather

Knoxville — Weather forecasters know that urban areas trap heat in asphault and concrete, but a University of Tennessee geologist said that big cities can create their own weather.

Dr. Ken Orvis said cities like Nashville and Atlanta often attract storms moving eastward.

“Convection over the city is enhanced, which sucks in thunderstorms going by,” Orvis said, “or it can actually make thunderstorms right over the city.”

Orvis said huge cities like New York City have so much rising heat in the summer that they divert thunderstorms around their edges.

But Orvis said he is not sure that other Tennessee cities would have such an effect on the weather.

“I don’t know about Memphis, but I would guess that Knoxville is too small to have a heat island that could change the weather.”