Two of the most commonly confused terms in weather are watches and warnings. And as WTOL 11 Chief Meteorologist Robert Shiels says, they have two very different meanings and it's very important that you understand the difference.
When you hear the term "watch" -- tornado or thunderstorm -- it means that conditions are right for a twister or a severe thunderstorm to form. It's a good idea to have a TV or radio nearby for frequent updates.
But when a warning is issued, that's a much different story. For severe thunderstorms, a "warning" means that one has been spotted and is moving into or is currently in a specific county or counties. In the case of a tornado warning, it means that a funnel cloud has actually been spotted or indicated by radar.
If given for your area or county, it means you should take immediate cover.
Knowing basic terminology is the first step in staying safe in a thunderstorm:
- A SEVERE THUNDERSTORM WATCH is issued by the Storm Prediction Center and means conditions are favorable for the development of thunderstorms that will exceed severe limits.
- A SEVERE THUNDERSTORM WARNING is issued by the local office of the National Weather Service. They use radar, satellite, lightning detectors, and spotters to follow thunderstorms and issue warnings for counties when severe weather is imminent.
Here are some safety tips for when a thunderstorm is approaching:
- If you can hear thunder, you are close enough to the storm to be struck by lightning. Seek safe shelter immediately.
- DO NOT seek shelter in small sheds, under isolated trees, or in convertible automobiles. Move to a sturdy building or car.
- If lightning is occurring and a sturdy shelter is not available, seek shelter inside a hard top car and keep windows up.
- Stay away from water, this includes boats.
- Telephone lines and metal pipes can conduct electricity. Avoid using the telephone or any electrical appliances. Use phones ONLY in an emergency.
- Do not take a bath or shower. Turn off air conditioners. Power surges from lightning can overload compressors.
- If you are boating or swimming, get to land and find shelter immediately
Knowing the difference between a tornado watch and a tornado warning can save your life.
- TORNADO WATCH - Conditions are favorable for the development of thunderstorms that will have a strong capability of producing tornadoes.
- TORNADO WARNING - A tornado has been spotted by a trained observer or Doppler radar has indicated a developing tornado and you should seek shelter immediately.
If a Tornado Warning is issued for your county, here are some steps you can take.
- If you are at home or in a small building, move go to the basement. A basement provides the safest shelter from a tornado.
- If there is not a basement in the building, move to an interior room or hall. The room should be small, such as a bathroom or closet on the lowest level of your house.
- If possible, make sure there are no windows in the room to avoid injury from flying glass.
- If you are at a school, hospital, factory, or shopping mall, there should be a pre-designated shelter area.
- If there is not, move to an interior hallway on the lowest floor, avoiding large windows or glassed areas.
- It is best if you stay away from large rooms like school gyms or dining rooms.
- You should crouch down and protect your head with your hands.
- If you are threatened by a tornado and you are in a high rise building move to center of the building.
History has proven that the worst place to get caught in a tornado is a mobile home or car. If a tornado threatens your area, leave the mobile home or car and seek shelter in a sturdy structure. If you are in a car and a sturdy shelter can't be reached, leave the car and lie in the nearest ditch, gully or low spot shielding your head with your hands. An automobile provides virtually no protection against the strong winds of a tornado.
Tornadoes are classified into three types:
- Weak Tornadoes (F0/F1) - These account for 70% of all tornadoes, causing less than 5% of tornado deaths. They may last from one to ten minutes with wind speeds less than 113 mph.
- Strong Tornadoes (F2/F3) - These account for 29% of all tornadoes, causing nearly 30% of tornado deaths. They may last for more than 20 minutes with wind speeds from 113 mph to 206 mph.
- Violent Tornadoes (F4/F5) - These account for 1% of all tornadoes, causing almost 70% of tornado deaths. They may last more than one hour, with wind speeds exceeding 206 mph. The forward speed is usually around 30 mph, but can vary widely from stationary to nearly 70 mph.
Tornadoes generally move from the southwest to northeast, but they can be unpredictable and change directions anytime. The bottom line for safety is to all seek shelter during a tornado and never try to outrun one if you are in a car. Tornadoes are often destructive and even deadly.