September 22, 2014

Climatologist talks about the meaning of “flash drought”

Many are calling this dry spell in July that followed the wettest spring on record a “flash drought.” Iowa State University extension climatologist, Elwyn Taylor, is not one of them. “Well, I wouldn’t. But that’s the term that they like to use these days when a drought sneaks up on people and all of a sudden it’s there when they didn’t realize it was coming,” he says.

Taylor says drought is defined by law as dryness in any county that cuts crop yields by 10-percent. So unless that happens for Iowa’s corn, Taylor isn’t using the word drought. “The trend for the nation this year for corn yield would be 160-bushels per acre. And so, if we ended up with a yield of 144 or less — then we’re in a drought,” Taylor explains.

“And this is a county-by-county deal, so there’ll be some counties in drought. We don’t know this will be the whole corn belt like it was last year.” As for the flash drought, Taylor says he understands why the term is being used.

“We had flash flooding earlier because we had so much rain that the streams were flooding, to now we’re in the weather pattern that will bring extensive dryness and heat. Well, if we can have flash floods, I guess we can have flash droughts as well,” Taylor says.

Taylor says slow moving polar weather patterns are lengthening the dry period just like they caused persistent spring rains.