• Thunderstorms affect relatively small areas. 
• A typical thunderstorm is 15 miles in diameter and lasts for about 30 minutes. 
• Severe thunderstorms can produce large hail or have winds of at least 58 mph. 
• Some wind gusts can exceed 100 mph and produce tornado-like damage.

Know the Warning Terms

Severe Thunderstorm Watch

Weather conditions are favorable for producing severe thunderstorms. Remain alert and stay informed. 

Severe Thunderstorm Warning

Severe weather has been reported or indicated on weather radar. Seek shelter immediately.

Before Severe Storms and Lightning

• Secure outdoor objects. 
• Close/shutter windows and secure outside doors. 
• Consider postponing outdoor activities. 
• Know where the nearest shelters are. 
• Know where to get weather reports. 
• Have a weather radio with battery backup. 
• Check your emergency kit – is it ready?

During Thunderstorms with Lightning

• The safest place to be during a thunderstorm is any normal building (with water pipes or electricity). 
  • Most hard top cars are safe from lightning. (It is the metal roof and metal sides that protect you, NOT the rubber tires.) 
  • Convertibles, motorcycles, bicycles, fiberglass vehicles offer no protection from lightning. 
• Avoid contact with interior metal during the storm. 
• No place outside is safe when thunderstorms are in the area. 
• If you hear thunder, lightning is close enough to strike you. 
• When you hear thunder, immediately move to safe shelter: a building or an enclosed, metal-topped vehicle with windows up. 
• Stay in safe shelter at least 30 minutes after you hear the last sound of thunder.

If you are outside and cannot find shelter

• Avoid tall trees, hilltops, open fields, beaches, cliffs. 
• Avoid ungrounded sheds or flimsy structures – especially in open areas. 
• If you are in a boat – get to shore and off the water as soon as possible and find shelter. 
• Get to the lowest area available that is not in flood area.

Facts About Thunderstorms

• Warm, humid conditions are favorable for storm development. 
• Storms may occur singly, in clusters or in lines. 
• Storms typically produce heavy rain for a brief period. 
• Ten percent of storms are severe – typically including high winds and large hail.

Facts About Hail

• Hail is larger than sleet and forms in thunderstorms. 
• Updrafts are strong rising currents of air within a storm that carry water droplets to a height where they freeze and become hail. 
• Hail can range from pea-sized (most common) to as large as baseball-sized or more. 
• Large hail stones fall faster than 100 mph and can injure or even kill people.

Facts about Lightning

• All thunderstorms produce lightning. If you can hear thunder, you are in range of lightning. 
• Lightning often strikes the same place repeatedly, especially if it’s a tall, pointed, isolated object. 
• Lightning can strike up to 15 miles from the center of the thunderstorm, far from the rain or storm cloud.