|SEVERE WEATHER SAFETY CENTER
Welcome to our updated severe weather safety center! We revised and updated these pages with all new information,
graphics, statistics, and much more. We firmly believe that knowledge is power, and the more a person knows about safety,
the more prepared he is. That's truly what safety is all about - PREPARDNESS. In today's complex and ever
changing society, their is still a fair amount of apathy and complacency among the general public when it comes to
severe thunderstorms and tornadoes. We tend to ignore the signs of their approach with ideas of "it won't strike me", or
"that storm will fade out before getting here". From a safety standpoint, these a very bad and even lethal ideas a person
can have. While it's true that the chances your location will ever be hit by a tornado for example, are very small, it is
still just as important to be prepared, just in case. That's where knowing safety rules comes in, and why we have created
these pages. One of our goals here at our office is to spread the word about safety, to educate everyone on what to
expect, what to do, and how to do it. If we all do our part, we can be prepared for the next severe storm or even tornado.
Do you know where the safest location is in your home? Click here to take a kind of "quiz" to
find out where safe areas are in not only your home, but in public places as well. While this is not really a quiz, it is
designed to "point out" potential safe areas. We do have a short "quiz" which you can take so you can find out what you
know about severe weather safety. To take the quiz, just head here.
A thunderstorm is considered "severe" when it goes from it's mature stage to severe before dissipating. At any
given moment, some 1,000 thunderstorms are in progress somewhere around the globe. Of these, roughly a third of them will
become severe. You see, not all thunderstorms which develop will ever become severe, but those that do become severe will
be capable to produce elements which can destroy, injure, and even kill. The National Weather Service classifies a
thunderstorm as "severe" if it contains any or all of these elements:
Other elements, though not listed above, are also just as dangerous during severe thunderstorms. One such element is the
lightening. Each year, lightening kills an average of 58 people in the United States. A single bolt of lightening can reach
a temperature of 50,000 degrees Fahrenheit, and pack up to 100 million volts of electricity! A person who is hit by
lightening recieves a severe electrical shock and may be burned. However, they carry no electrical charge and can handled
safely. If you witness someone struck by lightening, don't just stand there! Get medical attention at once. Another hazard
not mentioned is flash floods. Flash floods commonly occur when too much rainfall occurs over the same locations which the
ground is unable to absorb. The excessive rainwater thus drains into rivers, streams, and lakes causing them to rise. If
enough water gets into these rivers and streams, they flood over resulting in flash floods.
||WINDS >= 58 MPH
To learn more about flash flood safety, scroll down this page to that section.
In order for a thunderstorm to develop, the atmosphere needs to be "unstable". Instability results when warm and
moist air from the southern plains meets cool and dry air from the north. This meet usually occurs along boundarys called
"fronts". A unique kind of boundary, referred to as a "dry line" is often the focus for a more violent breed
of severe thunderstorms called "supercells". Supercell thunderstorms often unleash very large diameter hail and the
strong to violent tornadoes.
Whenever severe weather is forecast for your area, you need to be fully alert and prepared for what is expected. The
National Weather Service uses specific terminology when forecasting severe thunderstorms, tornadoes, and flash floods, so
be sure to become familiar with them. They could save your life! The table below will help explain what each term means
and what you need to do in each situation.
Although rare, sometimes conditions in the atmosphere may become volatile enough to produce very dangerous lines or clusters of
severe thunderstorms which produce widespread destructive straight-line winds that can exceed 95 mph. These events are known as
"Derechos". Derecho is Spanish meaning straight forward. Derecho events are classified as particularly dangerous
situations, so if such conditions are expected, everyone needs to be especially alert and monitoring the latest developments.
Another thing people need to understand is the fact that while in the majority of instances, tornadoes will not happen in areas
covered by a severe thunderstorm watch. However, in borderline cases it becomes quite difficult for forecasters to determine
whether the threat will be mainly large hail and damaging winds, or from those elements and tornadoes too. Therefore you should
treat a severe thunderstorm watch with the same importance as tornado watches.
WHAT IT MEANS ||
WHAT YOU SHOULD DO
SEVERE THUNDERSTORM WATCH
||Atmospheric conditions are favorable for severe thunderstorms in and close to the watch area.
||Continue with regular activity, but keep an eye to the sky every so often. Watch for signs of cumulus
clouds which tower up into the atmosphere. Be ready to respond quickly to a warning.
SEVERE THUNDERSTORM WARNING
||Doppler radar has detected severe thunderstorms either within or about to enter your county or parish.
||This is the time for immediate action! If outdoors, move indoors. Inside, stay away from all
windows and doors. Unplug electrical items likes stereos, computers, radios, hair dryers, and such. Never use the telephone
during a thunderstorm unless it's an emergency! The lightening may strike the line outside. If caught in your vehicle, remain
inside of it, but do not lean on the doors.
||Atmospheric conditions are favorable for severe thunderstorms and tornadoes in and close to the
||Continue with regular activity, but keep your eye on the sky occasionally especially if you will be outdoors.
Watch for signs of cumulus clouds which tower up into the atmosphere. Be ready to respond quickly to a warning.
||A rotation was detected on Doppler radar within a severe thunderstorm within or about to enter your county
or parish, or a tornado has been sighted by storm spotters on the ground near your location.
||TAKE COVER IMMEDIATELY! In most homes and small buildings, move at once to your basement or storm cellar.
In homes without a basement, move quickly to any interior small room or hallway on the lowest level of the building. Closets or
bathrooms make good choices. Protect yourself with a blanket. In mobile homes, get out and find a more sturdy shelter.
FLASH FLOOD WATCH
||Conditions are favorable for intense thunderstorm development. These thunderstorms may produce flash
flooding due to slow movement, or repeated development/movement(training) over the same locations.
||If you live near or along any river, stream, or creek, or other low lying location which can easily
flood, remain alert for signs of rising water levels. If you see flooding starting to happen, get to a safe location at once.
FLASH FLOOD WARNING
||Dangerous flash flooding is imminent, or now occuring in or near your location.
||If you live in the immediate threat area, evacuate at once for higher ground. Select a route that will
not take you into already flooded areas. Never drive through a flooded section of roadway, even if it looks shallow! The
depth of the water may be too great to allow for safe passage. Be extra cautious at night when it's harder to recognize
Here are some basic guidelines to know and follow in severe thunderstorm situations:
A)...If you plan to be at a local beach swimming, or having a picnic at the park, make sure you have a portable NOAA
weather radio along so you can hear the latest information, including any warnings for your area. If you see clouds
towering up into the atmosphere, you should think about heading to a shelter area. Beach pavillions are not safe areas
during thunderstorms. Running to your vehicle is not a wise choice either since the storm may produce damaging
winds or even a tornado. Your best option is a sturdy safe building.
B)...If you plan to be out on the lake in your boat fishing, or just crusing around, keep your eye on the sky occasionally.
Watch for clouds which tower up into the atmosphere. If you see such clouds towering, or a thunderstorm bearing
down on your location, or hear a special marine warning issued, head for safe harbor at once. If you have little time to do
so, and your vessle has a cabin, drop anchor and get inside the cabin. Stay away from metallic items. Be sure you have
a portable NOAA weather radio so you can hear the latest information.
C)...Summer usually results in many exciting outdoor activities and fun for everyone. This often includes camping, biking,
hiking, and numerous sporting and other important events. If you plan on any of these activities when their is a threat for
severe weather, be sure to take a NOAA weather radio along. With it, you can keep up with the very latest information,
including any watches or warnings for the area. But you also keep an eye to sky too, and watch for towering clouds up into
the atmosphere. This may be your clue to developing thunderstorms, and if you can hear thunder, it's wise to head for safe
shelter quickly. Don't wait for a warning to be issued, which may cause panic and fear, and you may not be able to reach
safety in time.
D)...If caught in your vehicle during a thunderstorm, remain calm but alert and continue driving at reduced speed. Be
watchful for damaging winds and flying debris or large hail. If such conditions develop, try to get to a safe sturdy building
at once. If no shelter is available, pull over and stop. Remain with your vehicle until the immediate danger is passed then
proceed with caution. In cases where a tornado is approaching, you need to get out and into a sturdy shelter at once.
Vehicles offer NO protection from a tornado.
E)...Lightening is a thunderstorm's single worst killer. If you are outdoors when thunderstorms approach, this includes
being at sporting events like golf, head for safe shelter quickly. If there is little time to reach shelter, try to get to your
vehicle. If all else fails, crouch down in an open area away from trees and power lines. Do not lie flat on the ground. Indoors,
make sure to stay away from all windows and doors. Don't operate electrical items during the storm.
F)...If you live in mobile homes, or other pre manufactored homes, you need to evacuate them immediately if damaging
winds or especially a tornado approaches. Even if well tied down and anchored, such homes can be flipped over and totally
destroyed in a tornado. Most mobile home parks now have proper shelter areas for use in such events.
The underlying message then is clear. Stay alert and informed, and monitor local weather conditions.
Second to lightening, the single most destructive element of severe thunderstorms are tornadoes. A tornado is a violent
twisting windstorm which is comprised of a "funnel" shaped pendant extending to the ground from the base of a thunderstorm.
It is not classified as a tornado unless the funnel cloud reaches the ground. Tornadoes come in a variety of sizes and
shapes ranging from the weakest (F0) to the most violent (F5) maxi-tornadoes. The winds of a tornado vortex have never been
accurately measured, but studies from tornado damage suggest they could well exceed 300 mph. The season of peak
tornado occurence is from April to September, but tornadoes have occured in every month. A tornado can form as a single
storm, or in groups. Sometimes, several smaller vortices will rotate around the main funnel. These vortices are called
"suction vortices". A tornado that moves over or forms over a body of water is known as a "waterspout".
In order for tornadoes to form, their first needs to be several ingredients or "parameters" which come together in
the atmosphere. When such conditions exist, the information is passed on to the public in the form of outlooks, watches, and
warnings. When the potential exists for severe thunderstorms and tornadoes, it is very critical for everyone to become
familiar with tornado safety rules, and have a pre arranged plan for safe action at the ready in case it's needed. Tornadoes
can occur very suddenly, and without prior advance warning. This means you may have only seconds to act!
The following safety tips were developed with your personal safety in mind. Make sure you review them thoroughly, as
they may save your life!
In most homes and small buildings, move at once to the basement or storm cellar. Try to get under something sturdy, such
as a heavy table or work bench in the center of the basement or cellar. If you have none of these items, then another safe
alternative would be under a stairwell. In each case, take along a heavy blanket or matress to protect yourself from flying
debris and glass. If your home does not have a basement or cellar, then move to any interior small room or hallway on the
lowest level of the dwelling. Closets or bathrooms are wise choices. Again, take along a heavy blanket to protect yourself
from flying debris and glass. Some people still open their windows before taking cover in a tornado, on the basis this will
equalize the pressure on the walls and roof. However, studies have concluded that opening windows with an approaching
tornado has "no effect" on the atmospheric pressure inside the home. In fact, if a tornado funnel actually got close enough
to your home, the violent winds will probably have already done most of the damage. Therefore, do not waste time with
opening the windows. If you reside in an apartment complex, the safest place to take cover is in the basement, or on the
lowest level in any interior small room or hallway. Be sure you have along something to protect yourself from flying debris
Among one of the least safest places to be during a tornado is a vehicle. A tornado can pick up a vehicle, and bounce it,
flip it, and toss it around like a toy, and when it's over completely destroy it. If you are caught
in your vehicle when a tornado is approaching, one of the first things you need to do is try to find a safe sturdy building to
take cover in. If you live in well populated cities and towns, there are a number of such places where you can find suitable
shelter. Otherwise, if you are not able to reach a safe place in time, simply pull over to roadside and stop. Get out of your
vehicle and into a ditch or ravine, or even a culvert. Have something available to protect yourself with. Above all, never
seek shelter under a highway overpass! These are not safe locations to be when a tornado threatens, and you place
yourself at substaintial risk for injury or even death. Another common myth is that you can outrun an approaching tornado.
While it is true that if you are familiar with the area, you can select routes which get you out of the path of the oncoming
tornado, attempting to outrun it is quite risky and unwise. You don't know how fast the tornado may be approaching, and
it could catch up with you. You are further ahead by choosing to locate available shelter.
Whenever you are away from your home, you should still think about safety when a threat for severe thunderstorms or
tornadoes occurs in your area. Most public places offer shelter areas for people to use during a tornado emergency. For
example, in the following places you would seek shelter in pre-designated locations...
When attending outdoor events such as meetings, picnics, sporting events, swimming at the beach, boating, camping,
or other outdoor activity, pay close attention to the local weather conditions if a tornado watch has been posted for your
area. Watch the sky every so often for signs of cumulus clouds that tower up into the atmosphere. Try to listen for any
thunder. Most of all, be sure to have a portable NOAA weather radio along. This will alert you to any warnings for your
area. If storms bear down on your location, head for a safe shelter area. Don't wait for a warning!
Like vehicles, pre-fabricated(mobile homes) or similar dwellings are NOT safe places during high wind events
which can be associated with or without thunderstorms, or especially when a tornado is approaching. Even if properly
tied down and anchored in concret footings, these homes can be torn up, flipped and tossed around, and completely
destroyed. Your best option is to evacuate them immediately if you see a tornado
approaching, or receive word of a tornado warning. Many mobile home parks today have underground storm cellars
available for the people to use. Check with your park manager to find out where shelter is located near you. If your park
is among the few, who still have no shelter available, evacuate your mobile home, and seek cover in a nearby ditch or
ravine. Take along something to protect yourself from flying debris and glass.
When thunderstorms develop and then produce heavy to torrential rainfall over various locations, the ground may be
unable to absorb all the water so quickly. In most urban city areas, this excess water drains off into sewers and other
drainage areas, while in rural locations, the excess water drains into nearby rivers, creeks, and streams causing them
to rise. If too much rainfall occurs, the sewers and other drainage areas, along with the rivers, creeks, and streams begin
to flood over, resulting in dangerous flash flood events. By definition though, a flash flood is a raging torrent of flood water
which can sweep up nearly everything in their path, including but not limited to trees, power lines, vehicles, boulders,
and even whole buildings like houses. People have been severely injured and even killed because they drove their vehicle
into a flooded section of roadway, and became stranded and trapped. Knowing what to do when flash floods are expected
can mean the difference between life and death. Here are some key things to remember:
- Shopping centers and/or malls, retail store chains, and resturants
- Schools, colleges, and universities
- Hospitals, clinics, and nursing homes
- Factories, machine shops, law offices, court houses, and other public places
The long and short of safety is knowing what to do in each instance, and having a thorough and complete knowledge of
safety rules and related information. This can go a long way toward your survival when such events occurs.
The information provided on this page is intended for instructional purposes to help educate the public about the dangers
of severe thunderstorms, tornadoes, and flash floods. It is not intended as a complete guide to severe weather safety. If
you would like additional information, please contact our office through the contact page, or you can contact your local
office of the National Weather Service.
- If you live in low lying areas which are subject to sudden flooding, remain alert and watch for signs of flooding
starting to occur. If you are camping near any river or stream watch for rising water levels.
- If you live near any rivers, creeks, or streams, keep a watch for signs of rising water levels. If you see flooding
starting to occur, evacuate the area at once! Don't wait for a warning to get issued!
- If flooding is occuring, stay out of those locations. Select a route that will get you to safer grounds. Do not go
back to your home for clothing, food or other supplies.
- Never drive your vehicle through a flooded section of roadway! The water depth may be too great to allow for
safe passage. If you become stranded in your vehicle in a flooded section of roadway, don't panic! Try to get out and move
to a dry area if possible. Remember, flash flood waters rise very quickly, and you could be engulfed in your vehicle.
- Be especially cautious at night when it's harder to recognize flood dangers.