Severe Weather Preparedness Week: Severe Thunderstorms & Tornadoes

Nicole Madden, Kaitlin Wright,

CHARLOTTE, NC — It’s day two of Severe Weather Preparedness Week here in the Carolinas and today’s topic focuses on severe thunderstorms and tornadoes. A thunderstorm is a storm that can produce lightning and thunder and is often times associated with heavy rain, strong wind, and even hail. The Carolinas experience 40-50 thunderstorm days per year with ten percent of those classified as severe.

For a storm to be categorized as severe it needs to meet one of three criteria :

  • has hail at least 1″ in diameter
  • damaging wind gusts at least 58 mph
  • or produces a tornado

A tornado is a rotating, violent column of air extending from the base of a thunderstorm to the ground. Not all thunderstorms produce tornadoes. But, a few ingredients are needed for a tornado to form: Moisture, wind shear, lift, and instability. Tornadoes can happen any time of the year, but the reason why the majority of storms occur during the spring and late fall is due to the strong cold fronts as warm and cold air masses collide to give that lift to storms. Warm, moist air at the surface is needed to rise to form a thunderstorm updraft. For a storm to rotate it needs shear, or a change of wind direction and increasing wind speed with height. This intense change in wind speed and direction causes a horizontal rotating column of air. The rising air within the updraft of the storm will tilt the horizontal column of air vertical. The faster the rotating column spins the more it will stretch from the base of the storm. . This is known as a funnel cloud and it’s not until it reaches the ground that it’s considered a tornado.

Tornadoes can have winds speeds in excess of 300 mph and track several states with damage paths more than one mile wide. Although, there is more opportunity for tornadoes to form during the spring and late fall with the collision of colder and warmer air from a cold front, they are possible any time of the year. The Carolinas have had a tornado every month. Most tornadoes occur between March and June with the most active month being May. April brings the most destructive and deadly tornadoes to the region.

It is important to know what to do in case of severe weather and knowing the difference between a tornado watch and a tornado warning is the first step. A tornado watch means conditions are possible for a tornado to occur. Take all necessary steps to ensure you have a plan in case a warning is issued. Think of it like the Wicked Witch of the West while she was on her bicycle in Kansas during the Wizard of Oz, Dorothy knew she could be a threat. Once, she turned into the Wicked Witch with the green makeup, hat, and broom, it was on. A tornado warning means a tornado has already been confirmed or has been identified on the radar. This means the storm is happening and you must take shelter immediately.

Download the WCCB Weather App to stay ahead of the storms. It will alert you of any watches or warnings and the WeatherWise teams will bring you live updates, so even if you need to take shelter from the storm away from your tv, or you lose power, you can still get all the information you need.