Thunderstorms are generally rain showers that contain thunder and lightning.  One simple way to identify a thunderstorm is by looking at its cumulonimbus clouds that are white and tower high into the sky.  Hail, high winds, or tornadoes may accompany in thunderstorms, especially those that are severe.  In the United States alone, approximately 100,000 of thunderstorms occur annually, yet only ten percent reach severe limits.  In order for the storms to be severe, there need to be a tornado, winds blowing at the rate of 58 mph or more (about 93 kph), or 3/4-inch (19 mm) hail.

While thunderstorms are indeed exciting to study, they are still dangerous.  Thunderstorm-related deaths have been reported each year; causes of death are usually from lightning strikes and flash flooding.  People spending time outdoors can hear the first rumbles of thunder before torrential rains and high winds arrive.  Whenever a thunderstorm arrives, go inside.  


Sadly, hundreds of people are injured by lightning yearly.  Avoid standing underneath trees or other tall objects that lightning may strike.  Even the most intense lightning can slice a tree and let that fall onto cars.  Sometimes it can mess up power lines, leaving a number of homes and businesses without power.  Keep in mind that whenever you hear thunder, you could be close enough to be struck by lightning, so seek shelter promptly.


Severe hailstorms can also create problems.  If a hailstone is about two inches in diameter, that is big enough to cause injuries.  Large hailstones can also cause cracks and dents onto vehicles.  So people need to head to a sturdy shelter to avoid possible injuries during a hailstorm.

*Flash Flooding

Thunderstorms moving slowly and dumping heavy rain create flooding instantly.  If necessary, the National Weather Service will prompt a flash flood warning for an area vulnerable to rivers cresting or water-covered roads.  Heavy rains can create ponds and flooding to streets and rivers, and they should be avoided by not driving through them.  Instead, turn around.    


Increasing winds are normally associated with thunderstorms.  These winds can be so strong, they may knock big trees onto roads.  Utility poles can be knocked down as well, and debris such as signs and is likely to be blown all over the place.  Mobile homes are certainly not the best place for protection, since they can be damaged by those high winds quite easily.  Find shelter at a sturdy building on the first floor.


Thunderstorms can produce tornadoes with little or no warning.  Tornadoes swirl, sometimes on land, and they have very high winds.  Catastrophic damages such as a demolished school building can happen in rural and urban areas.  Use a basement or the very first floor to keep safe from these twisters.

Thunderstorms occur year round in many parts of the world, and can be dangerous.  Remember this friendly tip from the National Weather Service:  If thunder roars, go indoors.  You would be close enough to be struck by lightning.