It is estimated that at least 1,000 thunderstorms are in progress somewhere around the globe as we speak. Many of these storms will be harmless
in nature, but some will become severe, and unleash their fiery of destructive elements! The most violent breed of severe thunderstorms are known
as "Supercells". Supercells often unleash violent tornado outbreaks, or widespread "Derecho" events. Derecho is Spanish meaning straight
forward. The most common elements of any "severe" thunderstorm are damaging straight-line winds of 58 mph or higher, large diameter hailstones of
at least 1 inch in diameter or larger, and of course, tornadoes. Other elements which are associated with severe storms are very heavy rainfall
which can result in dangerous flash floods, and vivid lightning displays. Knowing how to protect yourself from these storms is key to your own
Image at left shows thunderstorms as they appear from space. Taken from the International Space Station in 2016. Courtesy of NASA.
The most destructive element from a severe thunderstorm is known as a "tornado". By definition, a tornado is a violently rotating column of air in
the form of a funnel shaped pendent which extends from the base of a thunderstorm to the ground. It is not classified as a tornado unless the
funnel is on the ground! Tornadoes come in a variety of shapes and sizes, ranging from a thin rope-like funnel to a large wedge - often a mile or
more in width! The black or grey funnel may hop along and skip along the surface, and may appear as a single funnel, or as a group of tornadoes from
the same thunderstorm. The wind speed around a tornado vortex has never been accurately measured, but recent engineering studies from the damage left
by tornadoes seems to suggest the wind speeds could exceed 260 mph (EF5 rated tornado). Most tornadoes travel from the southwest to the northeast, but
have also traveled from northwest to southeast, at speeds ranging from stationary to 70 mph. A tornado which forms or moves over a body of water is
known as a "waterspout". Tornadoes of any magnitude can produce widespread destruction to property, and may even injure or kill people and animals in
their path. Their fore, it's very important to take shelter quickly when a tornado is approaching your location!
Image at left courtesy of NOAA/NWS 2016.
Large hail in the form of odd shaped balls of ice which falls from a thunderstorm to the ground can be very destructive to crops and other outdoor
vegetation. It can also damage buildings, trees, and vehicles. Hailstones under 1 inch in diameter can still be damaging, but is not considered as
"severe" hail by definition. Hail can range in size from peas to audio CD's! Hail is formed inside the storm when updraft's of air carry a raindrop
higher into the storm where colder air freezes the raindrop into ice. This ice pellet then drops back down into the warmer air where another raindrop
forms on the ice pellet. Again, updraft's lift the ice pellet into the colder air where it refreezes. This process continues until the ice ball becomes
too heavy to stay inside the storm, so it falls to the ground as hail. The larger the hailstone, the more impact it will have. Remember, large hail
can injure you!
Image at left courtesy of NWS 1998.
DAMAGING THUNDERSTORM WINDS!
Severe thunderstorms can produce dangerous gusts of straight-line winds which often exceed 58 mph. These are known as "micro bursts". Micro burst winds
can produce heavy damage to trees, power lines, signs, water towers, buildings, and vehicles. If these winds become strong enough, they may develop into
a Derecho event, producing a more widespread area of destruction. Derechos are rare, but have occurred. The strongest known Derecho wind reported was 136
mph. When severe thunderstorms approach which contains damaging winds, you should always take shelter.
Image at left courtesy of NOAA/NWS 2016.
YOUR SEVERE WEATHER SAFETY PLAN!
So, do you have a severe weather safety plan made? If you already have a plan in place, then you know what to do and where to go should severe weather
strike. But if you don't have a plan, then now is the time to create a plan. Before you create your plan though, you do need to do a few things.
One of those is to do a complete survey of where you live. Unless your well familiar with where you live, you need to know the general layout of the
building. This will help you to complete one part of your safety plan. Does your building have a basement for instance. Knowing what area of the building
is safest is the first part of your safety plan. Otherwise, my building does not have a basement, so where would the safest place be? The survey you do
will aid in finding this out. But now what if I live in a mobile home, where is the safest place to go? Unfortunately, for those of you who live in a
mobile home, there really is no safe place you can be. Even though the trailer may be tied down and well anchored, such units can be easily blown apart
by an F-2 rated tornado, or high winds. So if you live in a mobile home and you get word of a tornado warning, the best thing to do is evacuate it, and
head for a safer shelter area. The choices you make now, could mean the difference between life or death.
Everyday people are forced to make many choices about things in their lives, and even choices they don't want to make. Many of those choices will likely be
wise ones, but others, not so wise. In fact, if a bad choice is made, it could be lethal! At the surface, many people would say and believe that it's wise
to have a smoke detector in your home. Why? The obvious answer is to alert you should a fire happen somewhere inside the building. After all, where their is
smoke there is fire! In fact many schools, hospitals and clinics even take this a step further by conducting monthly fire drills. Why? So that everyone knows
where to go and what actions to take if a fire broke out in the building. Now you may be asking, okay, but what does this have anything to do with severe
weather safety? By having a plan of action should a fire break out, everyone will know what to do, and where to meet. That same holds true for developing a
severe weather safety plan! So that everyone knows what to do, and where to go for safety. Think about it. Wouldn't it be a lot better to be safe then sorry?
So now you have a few more choices to make!
* Did you know the taking shelter under a highway overpass is foolish and dangerous? It's true because the wind velocity is enhanced under the overpass,
and can actually pull a person from under the rafters out into the air. Never take shelter under a highway overpass!
* Did you know mobile homes are also very dangerous places during a tornado, or high winds. Even if your home is tied down and well anchored in
concrete footings, an F-2 rated tornado can blow it apart in seconds! You should evacuate a mobile home if a tornado is approaching!
* Did you know that tornadoes can pass through major cities? It's true, and has been reported. In our coverage region, the cities like Chicago, Illinois
and the twin cities of Minnesota all have been struck by tornadoes.
* More fast facts coming soon!
SAFETY IS NO ACCIDENT! GET PREPARED NOW BEFORE IT'S TOO LATE!
Your survival during any severe weather event depends on one vital factor. PREPAREDNESS! There is no time like the present to start preparing for
what may happen at anytime. We cannot stress the term preparedness enough because it's so critical. Remember, the more prepared you are now, the safer you will
be when the event happens. In this section, we will focus on creating your severe weather safety plan for use at home. We'll also mention what you should do while away
from home (i.e. shopping, or attending a public function). The following are some general guidelines to help you create a home severe weather safety plan:
Before you get started, you first need some basic knowledge about the home or dwelling you live in (if you have lived in this home for over a decade, you can skip this
step). Find out if their is a basement. Is this a full or partial basement? If their is no basement, does it have a crawl space beneath it? If the home does not have any
basement or crawl space, you need to find out where suitable shelter areas might be. Remember, every home is different, so you need to take this into account. If you run
into trouble finding suitable shelter areas inside you home, you can always contact the nearest office of the National Weather Service for assistance. They will send
someone to your home to help identify areas which can serve as shelter areas. Otherwise, once you have identified where the safest places are inside you home, you are
now ready to whip up your plan. The National Weather Services reccomends that you plan addresses two (2) primary things. Those are....
1. Where the shelter is located. And,
2. How to reach this area as quickly as possible.
You recall those high school days, and having fire drills conducted every so often! When the alarm sounded, everyone knew what to do, and where to meet outside the
building. That's because the school had a plan of action made up in advance. Everyone knew the plan and responded accordingly. This same scenerio holds true for
tornadoes. So, the very first thing to include in your plan is the designated "safe" area (basement, crawl space, or in an enclosed small room on the lowest level). You
also need a direct route to the shelter area. This path needs to be kept clear of boxes, clothes, toys, and such at all times. If you have an underground
storm cellar, you need to calculate the distance from your house to the entrance of the cellar. This will be very critical because the further you have to go to reach the
entrance of the cellar, the more time you spend in transit to the cellar. Remember, time is very precious when a tornado is approaching, so you need to get into the
cellar as quickly as is possible.
That brings us to the second thing - timing to reach your shelter of choice. Before 1980, the average lead time for most tornado warnings was three (3)
minutes. Unless shelter was immediately available in a short distance, there was increased potential for serious injuries, and even death. Three minutes is hardly
enough time to do anything, so it's no wonder deaths and injuries were so high. Today, the average lead time for tornado warnings is thirteen (13) minutes, thanks
largely to Doppler radar and it's capabilities. Yet, thirteen minutes is still not enough time. So we all need to work with what we do have. Here is where conducting
home tornado drills comes into the spectacle. By rehearsing your safety plan, you can lesson the time needed to reach your designated meet point. Such drills
should be done on a fair weather day. Unless you include it in your safety plan, instead of having everyone meet in the shelter area itself during a drill, perhaps you
can have your family meet outside in the back yard. It's open ended. Conducting tornado drills is not required by any local, state, or Federal laws, but it does give
your family a chance to practice the home safety plan. But what about in mobile homes, and public places? Just keep reading on.
For those who reside in pre manufactured homes (mobile homes), the only safe choice is to have a nearby shelter area you can get to on a moments notice.
Even though your home is well anchored and tied down, an F-2 rated tornado could easily destroy it in only seconds. This is why mobile homes are not safe
during a tornado or high winds. In the event their is no available shelter close by, get down into a ditch or ravine. Crouch down and protect your head with your hands.
In shopping centers and malls, hospitals and clinics, schools, nursing facilities, move quickly to pre-designated shelter areas. Such areas are usually marked
for easy acess. If you are unsure where to go, ask a staff member for assistance. Never run out to your parked vehicle for shelter!
Never be outside during a thunderstorm! If however, you are caught outside and no shelter is available, stay away from tall objects such as trees, power lines,
water towers, and bodies of water. Avoid being on hilltops or mountains. Try to get to a head-high clump of trees or brush. As an extreme last resort, crouch down
where you are in the open. Bend forward placing your hands on your knees. The idea is to remain as low of a target as possible. Remember, their is no safe
place outdoors from lightning.
When a severe thunderstorm WARNING is issued for your area, all outside activities should cease at once, and everyone should move indoors quickly. Inside,
stay away from all windows and doors. Unplug any electrical devices such as radios, TV's, computers, stereos, hair driers. Don't use the telephone during the storm
unless it's an emergency. The lightning may strike the line outside. During the day, keep a careful lookout and watch for signs of rotation in the clouds, wall cloud,
or a funnel cloud. If you observe any of these, or even a tornado on the ground, take cover at once! Never wait for a warning or run outside to capture
video of the tornado! This is not only foolish but dangerous.
SOME TERMS OFTEN USED IN PREDICTING SEVERE WEATHER YOU SHOULD KNOW!
As part of severe weather safety, the National Weather Service (NWS) uses some terms that everyone should know and understand. Each of the following terms has
a different meaning, and that is also explained as well as any actions you should take in each situation. This is important for safety because you need to know
what kind of weather to expect, and what actions to take!
A few extra things to bear in mind....:
1). Although rare, on occasion conditions in the atmosphere may come together and trigger a more serious outbreak of either straight-line winds, or violent
tornadoes. These kind of events are known as Particularly Dangerous Situations or PDS for short. When PDS conditions are expected to occur, special
statements are issued by the National Weather Service to the public using every means available. Everyone in these areas should prepare immediately for the
rapid development and approach of any thunderstorms! Remember, Derecho events can often pack winds in excess of 120 mph! The stronger more violent tornadoes
can pack winds of 260 mph or greater! Either event can cause extreme damage to property, and result in injury or death. PDS situations should NOT be
WHAT IT MEANS ||
WHAT YOU SHOULD DO
SEVERE THUNDERSTORM WATCH
||Atmospheric conditions are favorable for severe thunderstorm development in and close to the watch area over the next several hours.
||Continue with regular activity, but keep an eye to the sky every so often. If you see cumulus clouds towering up into the atmosphere, this could
indicate a developing storm. Be ready to respond if a warning is issued. Remember, severe thunderstorms can and generally do produce tornadoes, often with
little or no advance warning!
SEVERE THUNDERSTORM WARNING
||Doppler radar has detected severe thunderstorms either within or about to enter your county or parish.
||If you are outdoors, cease all activities and move inside your house or a safe building at once. Indoors, stay away from all windows and doors.
Don't use the telephone during the storm unless it's an emergency. The lightning could strike the line outside. Make sure to unplug all electrical items during the storm.
Remain alert and informed.
||Atmospheric conditions are favorable for severe thunderstorms and tornadoes in and close to the watch area over the next several hours.
||Continue with regular activity, but keep your eye on the sky occasionally especially if you will be outdoors. If you observe cumulus clouds towering
up into the atmosphere, this could indicate a developing storm. Be ready to respond if a warning is issued.
||A thunderstorm capable of producing a tornado has been detected on Doppler radar, or trained spotters have reported a confirmed tornado on the
||If you live in the direct downstream location from the reported tornado, take cover at once! Otherwise, remain fully alert and prepared
to take cover if necessary since the thunderstorm could produce additional tornadoes.
FLASH FLOOD WATCH
||Conditions are favorable for significant flash flooding over the next several
||If you live along or near to any river, creek, or small streams be alert and
watch for signs of rising water levels. If you observe flooding starting to occur, evacuate the area
at once. This also holds true for low lying areas which can flood easily.
FLASH FLOOD WARNING
||Flash flooding is imminent, or already occurring near your location.
||Evacuate the area immediately, and move to higher ground. Don't waste time
gathering clothes or food. Stay out of already flooded areas. Never attempt to cross a flooded
section of roadway! The water depth may be too great to allow for safe passage.
2). A common misconception amongst most people these days are that they actually feel less threatened during severe thunderstorm events as opposed to
tornado events. This stems apparently from the ideas that the storms will weaken and die out before reaching them, or change direction, and miss their location
altogether. While it is possible these scenarios may happen, chances are good that if your area is put under a severe thunderstorm warning, such severe weather
is most likely to occur. You should never assume that a severe thunderstorm won't strike and therefore let down your guard. Always treat a severe
thunderstorm warning as seriously as a tornado warning.
3). The issuance of a severe thunderstorm watch does not preclude the occurrence of tornadoes! In the vast majority of cases, tornadoes don't occur in
areas covered by a severe thunderstorm watch. However, in borderline cases, it becomes difficult for forecasters to fully determine whether or not tornadoes
may happen. It is for this reason people need to be aware that tornadoes could also occur during a severe thunderstorm watch period as well. In addition,
sometimes a watch can be issued for areas close to where you live, but your specific location is not included in the watch. Don't let this cause you to let
down your guard! If your area is close to the watch area, but not in the watch area, storms may still affect your area. Thunderstorms rarely ever follow a
straight line, or remain within man made boundaries created around them. So if your location is not "in" the watch area but close to it, you should also be
alert as well.
As previously mentioned above, the National Weather Service classifies a thunderstorm as "severe" if it contains one or more of the following:
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. Some
people have driven their vehicles into flooded sections of roadway, and became stranded and trapped inside their vehicle. This is outright foolish because
the flood water could sweep you and your vehicle away, and you could loose your life. Here are some key things to remember:
||WINDS >= 58 MPH
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
VERY IMPORTANT! Midwest Weather Service is a small private establishment created for the sole purpose of severe
local storm prediction and forecast services for our clients. We are in no way affiliate with, or have any ties with NOAA, it's National
Weather Service, or Storm Prediction Center. Our products are released for the coverage region we serve, and originate from, and are disseminated
by our Storm Center.
- 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 occurring, 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.