El Nino, Climate Change? What's Behind This Roller-Coaster Winter In WNC

ASHEVILLE, N.C. -- It's been a roller-coaster winter season here in the mountains.

So far we've seen record-breaking warmth, and record-breaking snow.

It's left many asking what's behind the big swings.

Shorts and t-shirts at Christmas. Then just a few weeks later, everyone's bundled up.

But what's to blame? This round of El Nino, or something much bigger, like climate change?

"Sometimes these two phenomena act together to give certain outcomes for a location," said Jake Crouch, a climatologist from the National Climatic Data Center in Asheville.

He says what we're experiencing is a naturally recurring event.

"Right now we're in a really strong El Nino. It's one of the strongest we've seen in our period of record," he said.

While El Nino has impacted local weather, the term is not interchangable with climate change. "Climate is separate from that. It doesn't necessarily drive the El Nino pattern."

Every two to seven years, sea-surface temperatures in the Pacific Ocean increase at a drastic rate. The result is a distinct separation between winter months.

"With a strong El Nino, we tend to start winter pretty warm. And then we end winter on a cooler note," Crouch added.

And wetter. That's exactly what's happening this winter.

December 2015 was the warmest winter on record, over 12 degrees above average in Asheville. Just a month later on January 22, single-day snow records in Asheville were set at 10.6 inches.

"That was just amazing," said Crouch. "Mind blowing numbers coming in."

Big extremes in a short timeframe: that's all El Nino.

However in the long term, you're also seeing the effect of climate change in the mountains.

"The past twelve months here in Western North Carolina are pretty representative of that," Crouch said.

2015 as a whole across the entire U.S. was one of the hottest ever, with four states recording the warmest year on record.

"We are warming the world. We are warming here in the U.S.. There is no doubt in the data, in historical data, that climate change is happening," noted Crouch.

The heat was accompanied by drought. From May 12 until October 8 of 2015, the North Carolina drought monitor registered abnormally dry conditions, and even moderate drought with deficits exceeding 5 inches.

So what's next on this roller coaster of weather?

"Global temperatures have risen to record levels, and we've seen that repeatedly throughout the years. I think that's the kind of cycle we're in here in Western North Carolina. I don't seen anything slowing down. Thus expect more extremes to our weather as well here in the mountains."