What are tornadoes?
A tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. The most violent tornadoes are capable of extreme destruction with wind speeds of up to 300 mph. They can destroy buildings, uproot trees and hurl vehicles hundreds of yards. They can also drive straw into trees. Damage paths can be in excess of one mile wide to 50 miles long. In an average year, about 1000 tornadoes are reported nationwide. On average 60-80 people die every year from tornadoes, with most of those deaths occurring in the United States.
How do tornadoes form?
Most tornadoes form from a thunderstorm. You need warm, moist air from the Gulf and cool, dry air from Canada. When these two air masses come together, they create instability in the atmosphere. A change in wind direction and an increase in wind speed (wind shear) with increasing height creates an invisible, horizontal spinning effect in the lower part of the atmosphere. Rising air in side the updraft tilts the rotating air from horizontal to vertical. An area of rotation, between 2 and 6 miles wide, now extends through much of the storm. Most strong tornadoes form within this part of strong rotation, known as a mesocyclone.
When are tornadoes most likely to occur?
Tornadoes can happen at ANY time of the year and at any time of the day or night. Tornadoes are most likely to occur between 3 p.m. and 9 p.m. In the southern states, tornado season is from March-May. Peak times for tornadoes in the northern states are during the summer. A few southern states have a second peak for tornado outbreaks in the fall.
Where do most tornadoes occur?
The geography of the central part of the United States, known as the Great Plains, is suited to bring all of the ingredients together to form tornadoes. Most tornadoes occur in this area every year and is why it is commonly known as “Tornado Alley”. Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Iowa, Missouri, Arkansas and Louisiana all make up Tornado Alley, however tornadoes have happened in all 50 states!
What is the difference between a tornado watch and warning?
Watch- conditions are favorable to develop tornadoes, tune into your local news channel, or radio for updates on the weather. Monitor it closely.
Warning- A tornado has either been indicated on radar, or a trained storm spotter or emergency management worker spotted a tornado and you need to take shelter NOW!
How can you protect yourself and your family from tornadoes?
Find a safe place in your house where household members and pets will gather during a tornado. A basement, storm cellar or an interior room on the lowest floor with no windows, some homes do not have any of these options, in that case a bathtub will provide you with some shelter. In a high-rise building, pick a hallway in the center of the building. You may not have enough time to go to the lowest floor. In a mobile home, choose a safe place in a nearby sturdy building. If your mobile home park has a designated shelter, make sure you share the location with everyone in your home. No mobile home is safe during a tornado. If you are in a car during a tornado, find a building to take shelter in or a low area such as a ditch, and lay flat, and cover your head. Practice drills regularly, especially if you live in Tornado Alley. Never open windows during a tornado! Get to shelter immediately.