Thunderstorms & Hail


All thunderstorms are dangerous and every thunderstorm produces lightning. The Southeastern United States is very likely to have lightning and thunderstorms, especially in the summertime.


Thunderstorms are the result of convection in the atmosphere. They are typically the by-product of atmospheric instability, where air masses of varying temperatures meet. Rapidly rising warm moist air serves as the engine for thunderstorms.


A typical thunderstorm can be three miles wide at its base, rise to between 40,000 to 60,000 feet in the troposphere, and contain half a million tons of condensed water. Conglomerations of thunderstorms along cold fronts (with squall lines) can extend for hundreds of miles. 

Thunderstorms contain tremendous amounts of energy derived from water condensation. According to the National Weather Service, a thunderstorm is classified as severe when it produces one of three elements:

  • A tornado
  • Hail at least 0.75 inches in diameter
  • Winds at least 58 miles per hour


While thunderstorms can occur in all regions of the United States, they are most common in the central and southern states because atmospheric conditions in these regions are most favorable for generating powerful storms.


Hailstorms are a potentially damaging formation of severe thunderstorms. Hail is created when strong rising currents of air within the storm, called updrafts, carry water droplets to a height where they freeze.

Ice particles will continue to grow in size, eventually larger than .75 inches causing them to become too heavy to be supported by the updraft and fall to the ground. 

Hail is larger than sleet and will only form inside a thunderstorm. The size of the hailstones is a direct function of the size and severity of the storm.

Thunderstorm and Lightning Safety

  1. Before a Storm

Before Thunderstorm and Lightning

  • Remove dead or rotting trees and branches that could fall and injure people or damage property.
  • Delay outdoor activities.
  • Remember the 30/30 Lightning Safety Rule: Go indoors if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay indoors for 30 minutes after hearing the last clap of thunder.
  • Secure outdoor objects that could blow away or cause damage.
  • Get inside a home, building or hard top vehicle (not a convertible). Although you may be hurt if lightning strikes your car, you are much safer inside a vehicle than outside.
  • Remember, rubber-soled shoes and rubber tires provide NO protection from lightning. However, the steel frame of a hard-topped vehicle provides increased protection if you are not touching metal.
  • Shutter windows and secure outside doors. If you can’t find shutters, close window blinds, shades or curtains.
  • Unplug any electronic equipment well before the storm arrives.
    • If in a forest: Seek shelter in a low area under a thick growth of small trees.
    • If in an open area: Go to a low place such as a ravine or valley. Be alert for flash floods.
    • On open water: Get to land and find shelter immediately.
    • Anywhere you feel your hair stand on end: Squat low to the ground on the balls of your feet. Place your ears over your head between your knees. Make yourself the smallest target possible and lessen your contact on the ground. DO NOT LIE FLAT on the ground.

Know the Terms

Familiarize yourself with these terms to help identify a thunderstorm hazard:

Severe Thunderstorm Watch - Tells you when and where severe thunderstorms are likely to occur. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio or television for information.

Severe Thunderstorm Warning - Issued when severe weather has been reported by spotters or indicated by radar. Warnings indicate imminent danger to life and property to those in the path of the storm.

Additional Resources

Want to learn more about thunderstorms, lightning and hail? Visit these sites to learn about the science behind these systems and how to be prepared:

Listen to Local Officials

In any emergency, always listen to the orders given by local emergency management officials.