Thunderstorms
A thunderstorm affects a relatively small area when compared to a hurricane or a winter storm. The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Despite their small size,
ALL thunderstorms are dangerous! Of the estimated 100,000 thunderstorms that occur each year in the United States, about 10 percent are classified as severe.
Tornadoes
Although tornadoes occur in many parts of the world, they are found most frequently in the United States. In an average year, 1,200 tornadoes cause 60-65 fatalities and 1,500 injuries nationwide.
- A tornado is a violently rotating column of air extending from a cumuliform cloud, such as a thunderstorm, to the ground.
- Tornadoes may appear nearly transparent until dust and debris are picked up or a cloud forms within the funnel.
- The average tornado moves from southwest to northeast, but tornadoes can move in any direction and can suddenly change their direction of motion.
- The average forward speed of a tornado is 30 mph but may vary from nearly stationary to 70 mph.
- The strongest tornadoes have rotating winds of more than 200 mph.
- Tornadoes can accompany tropical storms and hurricanes as they move onto land.
- Waterspouts are tornadoes that form over warm water. Water spouts can move onshore and cause damage to coastal areas.
Be Ready Year Round
- Tornadoes can occur at any time of day, any day of the year.
- Have a plan of action before severe weather threatens. You need to respond quickly when a warning is issued or a tornado is spotted.
- When conditions are warm, humid, and windy, or skies are threatening, monitor for severe weather watches and warnings by listening to NOAA Weather Radio, logging onto weather.gov or tuning into your favorite television or radio weather information source.
Tornado Fiction and Fact
- FICTION : Lakes, rivers, and mountains protect areas from tornadoes.
- FACT : No geographic location is safe from tornadoes. A tornado near Yellowstone National Park left a path of destruction up and down a 10,000 foot mountain.
- FICTION : A tornado causes buildings to “explode” as the tornado passes overhead.
- FACT : Violent winds and debris slamming into buildings cause the most structural damage.
- FICTION : Open windows before a tornado approaches to equalize pressure and minimize damage.
- FACT : Virtually all buildings leak. Leave the windows closed. Take shelter immediately. An underground shelter, basement or safe room are the safest places. If none of those options are available, go to a windowless interior room or hallway.
- FICTION : Highway overpasses provide safe shelter from tornadoes.
- FACT : The area under a highway overpass is very dangerous in a tornado. If you are in a vehicle, you should immediately seek shelter in a sturdy building. As a last resort, you can either: stay in the car with the seat belt on. Put your head down below the windows, covering with your hands and a blanket if possible, OR if you can safely get noticeably lower than the level of the roadway, exit your car and lie in that area, covering your head with your hands. Your choice should be driven by your specific circumstances.
- FICTION : It is safe to take shelter in the bathroom, hallway, or closet of a mobile home.
- FACT : Mobile homes are not safe during tornadoes! Abandon your mobile home to seek shelter in a sturdy building immediately. If you live in a mobile home, ensure you have a plan in place that identifies the closest sturdy buildings.
Tornado Safety Rules
Occasionally tornadoes develop so rapidly that advance warning is not possible. Remain alert for signs of an approaching tornado such as a dark, often greenish sky, large hail, or a loud roar similar to a freight train.
- The safest place to be is an underground shelter, basement, or safe room.
- If no underground shelter or safe room is available, a small, windowless interior room or hallway on the lowest level of a sturdy building is the safest alternative.
- Mobile homes are not safe during tornadoes. Abandon mobile homes and go to the nearest sturdy building or shelter immediately.
- If you are caught outdoors, seek shelter in a basement, shelter or sturdy building. If you cannot quickly walk to a shelter:
- Immediately get into a vehicle, buckle your seat belt and try to drive to the closest sturdy shelter.
- If flying debris occurs while you are driving, pull over and park. Now you have the following options as a last resort:
- Stay in your vehicle with the seat belt on. Put your head down below the windows, covering with your hands and a blanket if possible.
- If you can safely get noticeably lower than the level of the roadway, exit your car, and lie in that area, covering your head with your hands.
- Your choice should be driven by your specific circumstances
Lightning
- There is no safe place outdoors when a thunderstorm is nearby.
- The vast majority of lightning victims were going to a safe place but waited too long before seeking safe shelter.
- More than 80% of lightning fatality victims are male, typically between the ages of 15 and 40.
- Lightning fatalities are most common during summer afternoons and evenings.
- The energy from one lightning flash could light a 100-watt light bulb for more than 3 months.
- Many wildfires in the western United States and Alaska are ignited by lightning.
- The channel of air through which lightning passes can be heated to 50,000°F—hotter than the surface of the sun! The rapid heating and cooling of the air near the lightning channel causes a shock wave that results in the sound we know as “thunder.”
How Far Away Is the Lightning?
Count the number of seconds between a flash of lightning and the sound of the resulting thunder. Divide this number by 5 to get an estimate of the distance in miles to the lightning strike. Remember, if you are outdoors and can hear thunder, you are in danger of being struck by lightning.
Lightning Fiction and Fact
- FICTION : If it is not raining, then there is no danger from lightning.
- FACT : Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall. This is especially true in the western United States where thunderstorms sometimes produce very little rain.
- FICTION : The rubber soles of shoes or rubber tires on a car will protect you from being struck by lightning.
- FACT : Rubber-soled shoes and rubber tires provide NO protection from lightning. The steel frame of a hard-topped vehicle provides increased protection if you are not touching metal. Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside.
- FICTION : People struck by lightning should not be touched because they carry an electrical charge.
- FACT : Lightning-strike victims carry no electrical charge and should be helped immediately. Anyone who has been hit by lightning requires immediate professional medical care. Call 9-1-1 and begin CPR immediately if the person has stopped breathing. Use an Automatic External Defibrillator if one is available. Contact your local American Red Cross chapter for information on CPR and first aid classes.
- FICTION : “Heat lightning” occurs after very hot summer days and poses no threat.
- FACT : “Heat lightning” is a term used to describe lightning from a thunderstorm too far away for the thunder to be heard.
