Is Nashville's climate changing?

Sunday, August 22, 2010 at 11:45pm

Weather patterns in Middle Tennessee can be pretty up and down. But this year, residents have experienced the limits of what Mother Nature has to offer: bitter cold and snow in February, heavy rains and flooding in May, and scorching heat and near-record temperatures this summer.

“It certainly has been a year of extremes,” said National Weather Service Meteorologist Bobby Boyd, adding that weather records dating back 140 years show the area goes through wet-dry periods and hot-cold spells.

Does the dramatic range this year mean Earth is about to spin into the sun? Nah.

But Boyd said the climate is changing.

“I don’t think there’s any question, and most meteorologists and climatologists would agree, that climate is changing and always has been,” he said.

He said the recent hot streak — broken Thursday by record rainfall and a high of 84 degrees — was unusual.

The high temperatures included 31 consecutive days (July 18 to Aug. 17) with temperatures at 90 degrees or higher. Although that didn’t break the 34-day record set during the blistering hot summer of 2007, it tied the record for the second-longest string of 90 degree-plus days. To find other 31-day strings, one must look all the way back to 1952 and 1954.

“We’ve had a stretch of hot weather all summer,” Boyd said. “The difference this summer has been that we’ve had real high humidity levels. It’s unusual to have high temperatures and high humidity levels. And that’s what’s made it so miserable — high humidity levels and high dew point levels coupled with hot temperatures.”

In general, triple-digit temperatures (the official high at Nashville International Airport hit 101 degrees on Aug. 4.) are accompanied by relatively low humidity, Boyd said, citing droughts in 1980, 1988 and 2007, when several temperature records were shattered.

“I think weather and meteorology goes through cycles. We go through hot periods. We go through cold periods. It goes through cycles. That’s something that’s always existed in our record. And climate does change as we go through time.”

4 Comments on this post:

By: jrminkel on 8/23/10 at 7:29

I was disappointed to see Mr. Boyd make no mention of global warming as a source of climate change in Nashville and elsewhere. Statistically, the kind of flooding Middle Tennessee experienced in May is to be expected only once every 1,000 years. It's true that no single weather event can be attributed to global warming. But global warming-induced climate change loads the dice in favor of extreme flooding by releasing more water vapor into the atmosphere. The current flooding in Pakistan as well as the recent heat wave and wildfires in Russia both point to global warming-induced climate change taking place around the globe. It would have been nice for Mr. Boyd to acknowledge that we are not simply passing through a cyclical phase.

By: SirKnight on 8/23/10 at 10:07

Ha, ha. Sarcasm noted, jrminkel!

By: yogiman on 8/23/10 at 1:50

Well, maybe Mr. Bord should check it out with Al Gore. Al can tell him what the weather uis going to be... can't he?

By: yogiman on 8/23/10 at 1:51

Excuse me, I meant Boyd. Sorry, Bobby.