'Thousand-year' events like historic flooding on NC coast due to climate change, weather experts say

Communities along the Carolina coast are continuing to dry out after last week's deadly storm that dumped upwards of 20 inches of rain in localized spots.

The storm , dubbed a "thousand-year event" by some climatologists, is the type of system experts say we may need to get used to in the years to come.

In fact, in just the last 25 years there have been nine storms along the Carolina coast that would meet the definition of a multi-hundred or thousand-year event.

"When we talk about 500-year, thousand-year flood event, or ten-year flood event, it doesn't mean it can't happen two months from now. It doesn't mean it can't happen next year," said Steve Pfaff, meteorologist-in-charge with the NWS' Wilmington office.

Pfaff says that Potential Tropical Cyclone 8 -- the unnamed storm that wreaked havoc last week -- had all the ingredients of a highly impactful, wet system despite not having a name.

"I think it just goes to really teach us again that it doesn't have to have a name to have impacts associated with it," Pfaff said.

The term "thousand-year event" relates to the probability that a storm or flood event could occur in a given year -- in the case of thousand-year storms, .1%. But Pfaff says since Hurricane Floyd in 1999, they've become significantly more common.

"The problem that we're seeing is a lot of these multi-hundred-year thousand-year events that have occurred just in our office's area of responsibility has increased markedly since Hurricane Floyd in 1999," he said.

Despite many coastal residents being caught flat-footed by the storm, Kathie Dello with the State Climate Office of North Carolina says it wasn't the forecast that was off -- but the communication.

"Some of the models had 15-plus inches of rain in them. But we're talking about forecasting things that haven't happened in the past," Dello said.

Dello believes that warmer water and air in the atmosphere are supercharging these storms -- pushing the limits of North Carolina weather.

"So we've been having this weather whiplash here in North Carolina, swinging back and forth between extremes. The dry is really dry and the wet is really wet. It's tough to prepare for both," she said.