Law and Public Safety

Law and Public Safety

Tornadoes

Tornado Picture

Tornadoes are one of nature's most violent storms. They can appear suddenly without warning and can be invisible until dust and debris are picked up or a funnel cloud appears. Planning and practicing specifically how and where you take shelter is a matter of survival. Be prepared to act quickly. Keep in mind that while tornadoes are more common in the Spring time, they can occur at any time of the year, making advance preparation important. When the outdoor warning siren system is activated, you should seek shelter in a basement or designated safe area in your home, business or school. Once you are in a safe area, seek information about the storm from the local media or NOAA Weather-Alert Radio.


Should you lose power after a tornado and plan on using a generator, be sure to follow generator safety tips to keep you, your family and others safe.

Download this informative .pdf entitled, "Before, During and After a Tornado: What to do" and share the information with friends and family so we can can be prepared for one of our areas most frequent hazards. Or watch one of these videos produced by Missouri's State Emergency Management Agency (SEMA):



Tornado Terms:

TORNADO WATCH: Tornadoes are possible in your area. Remain alert for approaching storms. 


TORNADO WARNING: A tornado has been sighted or indicated by weather radar. If a tornado warning is issued for your area, move to your pre-designated place of safety. Once you are in your basement or safe room, turn on a TV, AM/FM radio or NOAA Weather-Alert Radio. Do not leave your safe area until the storm has passed. 


How to Prepare For a Tornado:

Be alert to changing weather conditions.


  • Listen to a NOAA Weather-Alert Radio or local media for the latest information.
  • Look for approaching storms
  • Look for the following danger signs:

  •    Dark, often greenish sky
       Large hail
       A large, dark, low lying cloud (Particularly if rotating)
       Loud Roar, similar to a freight train

If you see approaching storms, any of the danger signs, or you hear the outdoor warning siren system, be prepared to take shelter immediately.


What to Do During a Tornado

If you are under a tornado WARNING, take shelter immediately!


  
If you are in:
A structure (e.g. residence, small building, school, nursing home, hospital, factory, shopping center, high-rise building)
Then:
Go to a pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Get under a sturdy table and use your arms to protect your head and neck. Do not open windows.
 
If you are in:
A vehicle, trailer, or mobile home
Then:
Get out immediately and go to the lowest floor of a sturdy, nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.
 
If you are:
Outside with no shelter
Then:
Lie flat in a nearby ditch or depression and cover your head with your hands. Be aware of the potential for flooding.
Do not get under an overpass or bridge. You are safer in a low, flat location.
Never try to outrun a tornado in urban or congested areas in a car or truck. Instead, leave the vehicle immediately for safe shelter.
Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.

What To Do After a Tornado:

Recovering from a disaster is usually a gradual process. Safety is a primary issue, as are mental and physical well-being. If assistance is available, knowing how to access it makes the process faster and less stressful. This section offers some general advice on steps to take after disaster strikes in order to begin getting your home, your community, and your life back to normal.



Tornado Myths:

MYTH: Areas near rivers, lakes, and mountains are safe from tornadoes. 
FACT: No place is safe from tornadoes. In the late 1980's, a tornado swept through Yellowstone National Park leaving a path of destruction up and down a 10,000 ft. mountain.


MYTH: The low pressure with a tornado causes buildings to "explode" as the tornado passes overhead.
FACT: Violent winds and debris slamming into buildings cause most structural damage.


MYTH: Windows should be opened before a tornado approaches to equalize pressure and minimize damage.
FACT: Opening windows allows damaging winds to enter the structure. Leave the windows alone; instead, immediately go to a safe place.

How do Tornadoes Develop?

Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts. These thunderstorms often produce large hail, strong winds, and tornadoes. Tornadoes in the winter and early spring are often associated with strong, frontal systems that form in the Central States and move east. Occasionally, large outbreaks of tornadoes occur with this type of weather pattern. Several states may be affected by numerous severe thunderstorms and tornadoes.

graphic of a horizontal spinning effect

 Before thunderstorms develop, a change in wind direction and an increase in wind speed with increasing height creates an invisible, horizontal spinning effect in the lower atmosphere.

graphic of rising air tilting rotating air from horizontal to vertical

 Rising air within the thunderstorm updraft tilts the rotating air from horizontal to vertical.

a graphic depicting an area of rotation

An area of rotation, 2-6 miles wide, now extends through much of the storm. Most strong and violent tornadoes form within this area of strong rotation.


Tornadoes Take Many Shapes and Sizes

Weak tornado Strong tornado Violent tornado

Weak Tornadoes
  • 69% of all tornadoes
  • Less than 5% of tornado deaths
  • Lifetime 1-10+ minutes
  • Winds less than 110 mph

Strong Tornadoes
  • 29% of all tornadoes
  • Nearly 30% of all tornado deaths
  • May last 20 minutes
  or longer
  • Winds 110-205
  mph

Violent Tornadoes
  • Only 2% of all tornadoes
  • 70 % of all 
   tornado deaths
  • Duration Can 
    exceed 1 hour

County Police Logo
Office of Emergency Management (OEM)
14847 Ladue Bluffs Crossing Dr.
Chesterfield, MO 63017
Telephone: (314) 628-5400
Email: msmiley@stlouisco.com