Why do tornadoes form during Tropical Storms like Debby (+ will NC get another)?

On Wednesday night, Tropical Storm Debby brought tornadoes to the Carolinas, a typical occurrence for tropical systems.

North Carolina had “several confirmed tornadoes overnight,” and there’s a possibility that more could touch down, according to Jonathan Blaes, a meteorologist with National Weather Service Raleigh.

In Lucama, a town just over 50 miles east of Raleigh, a man was found dead inside of his home, which was damaged by a tornado, The Charlotte Observer previously reported. At least 10 other homes were damaged, and portions of a middle school were destroyed.

“We’re still watching the storm, which is capable of producing tornadoes across northeastern North Carolina,” Blaes said.

At least one tornado usually forms during tropical storms in the United States, according to the National Ocean Service.

Why do tornadoes form during storms?

Hurricanes and tropical storms have a “strong vertical shear” — change in wind speeds and direction, according to AccuWeather — and the instability creates favorable conditions for a tornado.

Hurricanes are considered unstable because they bring with them warm, moist air that wants to rise above a layer of cooler, less-moist air, according to LiveScience.

Tornadoes spawned by hurricanes often form in the system’s rain bands, which extend far away from its center, according to the National Science Foundation. But they can also form near the eyewall, which is the ring of clouds that surround the storm’s eye.

“In general, tornadoes associated with hurricanes are relatively weak and short lived, especially in comparison to those that occur over the Great Plains of the United States,” the National Science Foundation says. “Nonetheless, the effects of tornadoes, added to the effects of hurricane-force winds, can produce substantial damage.”

What are the signs of a tornado?

A developing tornado may include these indicators, according to the National Weather Service:

• Rotating funnel-shaped cloud

• Approaching cloud of debris

• Dark or green-colored sky

• Large, dark, low-lying cloud

• Large hail

• A loud roar that sounds like a freight train

If you notice any of these signs, you should take cover immediately and monitor local media for weather alerts.

How to prepare for a tornado

Here are some ways you can prepare for a tornado, according to the Centers for Disease Control and Prevention:

• Identify the safest place to take shelter in your house, such as storm cellar, basement or inside room without windows.

• Create and practice a tornado emergency plan.

• Write down important phone numbers, including emergency numbers, insurance policy types and vehicle registration information.

• Store important documents in a safe location

• Prepare an emergency supplies kit, with items for first aid, water and food

• Remove possible hazards, like heavy items stored on high shelves.

This story was originally published August 8, 2024 at 12:18 PM.

Evan Moore

The Charlotte Observer

Evan Moore is a service journalism reporter for the Charlotte Observer. He grew up in Denver, North Carolina, where he previously worked as a reporter for the Denver Citizen, and is a UNC Charlotte graduate.