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My name is Jennifer Kitsmiller and I am a meteorologist with the National Weather Service
in Missoula, Montana. As we approach the late spring and summer months, the threat for lightning
greatly increases across Montana and Idaho. Being that we are in a part of the country
that enjoys the great outdoors, there are times that we are all exposed to the danger
of lightning. Lightning leads to an average of 54 deaths a year in the United States and
is a factor that should never be ignored. We hope this short video will help to educate
about the dangers of lightning and provide some guidance on how to minimize the likelihood
of injury or death from lightning.
First things first, what causes lightning? Understanding the science of lightning is
just the first step in understanding why it is so important to get to a safe place anytime
thunderstorms are in the area. If you can hear thunder, even a distant rumble or a crackling
aloft, you are already in danger of becoming a lightning victim. With rare exception (such
as volcanic eruptions and large forest fires), virtually all lightning is produced by thunderstorms.
In simple terms, lightning is a giant spark of electricity between the atmosphere and
the ground. Ice is a key component to lightning, and thus lightning occurs only in clouds that
extend above the freezing level. As bits of ice within the cloud collide, friction results
in an electrical charge, which builds up over time. Typically, a negative charge ends up
concentrated at the bottom of the cloud, and since opposites attract, a positive charge
builds at the surface. The ground's electrical charge tends to concentrate on things that
stand up, such as mountains, trees, or even people. The charge streaming up from these
higher points will eventually connect with the charge from the cloud, and a lightning
strike is born. The massive amount of heat generated from the lightning bolt (in excess
of 50,000 degrees Fahrenheit) causes the air to expand rapidly, resulting in thunder.
Air is generally a poor conductor of electricity, however, if the charge difference between
the cloud and the ground becomes too large, the insulating capacity of the air starts
to break down. This breakdown occurs on a molecular level and allows negative charges
to start moving more freely, in what is called a stepped leader. The actual lightning stroke
is preceded by the stepped leader, which makes a rapid and staggered advance of negatively
charged air from the base of the cloud. When the stepped leader approaches the ground,
a spark surges upward from the ground towards the stepped leader. When the two connect,
a pathway is created for the flow of electricity, which initiates a series of brightly illuminated
strokes. Because individual strokes occur in rapid succession, lightning appears to
flicker and flash. This video demonstrates what a lightning strike looks like in slow
motion. Although the video is about 30 seconds long, the depicted lightning strike actually
occurs in only a fraction of a second.
From 2002-2011, 3 deaths were reported in Montana and 2 in Idaho resulting directly
from lightning. Although when compared to the national average, Montana and Idaho have
relatively few reported deaths, if you weight these deaths by the population of each state,
Montana ranks in the top 10 for lightning fatalities and Idaho ranks in the top 20.
This is largely due to our small populations, but can also be partly attributed to our outdoor
loving culture, which leaves many people exposed to the elements each year.
So what is the most likely time of year for people to be struck? July tops the list due
to it being at the peak of summer when many outdoor activities are occurring across the
country. The statistics also show that men are more likely to get struck by lightning
than women. From 1995 to 2008, 82 percent of lightning fatalities were male. The commonly
accepted reason for this is that men tend to take more risks in lightning storms and
tend to have more outside related jobs. Sports related or recreational activities
are involved in almost half of all lightning related deaths.
There are a lot of myths that surround lightning. Part of lightning education is understanding
the truths about lightning. How many of these have you heard before?
Myth 1: Lightning never strikes the same place twice.
Fact: Lightning often strikes the same place repeatedly, especially if it's a tall or
isolated object. The empire state building gets hit nearly 100 times a year. Higher terrain
such as mountain peaks are also a frequent target for lightning.
Myth 2: If it's not raining or there aren't clouds overhead, you're safe from lightning.
Fact: Lightning often strikes more than three miles from the center of the thunderstorm,
far outside the thunderstorm cloud. In fact, bolts can strike as much as 10-15 miles from
a thunderstorm. If you can hear thunder, lightning is within striking distance. As the saying
goes, when thunder roars, go indoors. Once in a safe location, it is recommended you
stay there for thirty minutes after you hear the last roar of thunder.
Myth 3: Rubber tires on a car protect you from lightning by insulating you from the
ground. Fact: Most cars are safe from lightning, but it is the metal roof and sides that protect
you, NOT the rubber tires. Remember, convertibles, motorcycles, bicycles, open-shelled outdoor
recreational vehicles and cars with fiberglass shells offer no protection from lightning.
When lightning strikes a vehicle, it goes through the metal frame into the ground. Don't
lean on doors during a thunderstorm.
Myth 4: A lightning victim is electrified. If you touch them, you'll be electrocuted.
Fact: The human body does not store electricity. It is perfectly safe to touch a lightning
victim to give them first aid. Cardiac arrest is the immediate cause of death for those
who die from lightning strikes, however some deaths can be prevented if the victim receives
the proper first aid immediately. If someone is struck, call for help immediately by dialing
9-1-1. If the victim is unresponsive or not breathing, begin CPR or use an Automatic External
Defibrillator (AED) if one is available. If possible, move the victim to a safer place.
Lightning can strike twice. Although only about 10% of people who are struck by lightning
are killed, the other 90% often suffer from various degrees of disability. A few side
effects from lightning strikes include short-term memory loss, difficulty with multitasking,
slowed reaction time, irritability, personality change, forgetfulness, intense headaches,
ringing in the ears, dizziness, nausea and vomiting, and difficulty sleeping.
Myth 5: If outside in a thunderstorm, you should seek shelter under a tree to stay dry.
Fact: Being underneath a tree is the second leading cause of lightning casualties. Lightning
is attracted to tall objects, particularly when they are isolated. As tempting as it
may be to take shelter from the rain under a tree, this is not a good course of action.
Myth 6: If trapped outside and lightning is about to strike, you should lay flat on
the ground. Fact: Laying flat increases your chance of being affected by potentially deadly
ground current. If you are caught outside in a thunderstorm, you should keep moving
towards a safe shelter. If you cannot reach shelter use the lightning crouch position
which is pictured above. By making yourself as small as possible and minimizing your contact
with the ground, you will decrease the likelihood of being affected by a lightning strike.
So what should you do when a thunderstorm approaches? If you are inside an enclosed
building, you should be relatively safe from a lightning strike. However, with a few added
precautions, you will further increase your safety. It is wise to stay off corded telephones.
Electricity can travel through the wiring in your home if it is struck. There have been
reports of individuals being struck while talking on the phone. Cell phones, however,
are safe. Likewise, don't touch electrical equipment or cords during a lightning storm.
Avoid plumbing. Activities such as doing the dishes or taking a shower should be avoided.
Stay away from windows, doors and concrete walls which could leave you exposed to the
current. What should you do if you are outside when
a thunderstorm approaches? The best option is to plan ahead. Monitor
the weather forecast for thunderstorms, and consider postponing activities to avoid being
caught in a dangerous situation. If you do continue on with your plans, know where you
will go and how long it will take to get there if threatening weather emerges. Make sure
to monitor the weather while you are outside. Look for signs of a developing thunderstorm
such as darkening skies, flashes of lightning or increased winds. Remember, no place outside
is safe from lightning! If you hear thunder, lightning is close enough to strike. Immediately
move to an indoor shelter such as an enclosed building or a car with a metal roof and sides.
Once you are in a safe shelter, stay there until 30 minutes after you hear the last clap
of thunder.
If you are caught outside with no safe shelter anywhere nearby, the following actions may
reduce your risk. Immediately get off elevated areas such as hills, mountain ridges or peaks.
Avoid open areas. Don't be the tallest object around. NEVER lay flat on the ground. Use
the lightning crouch position demonstrated earlier. NEVER use a tree, cliff or rocky
overhang for shelter. Immediately get out and away from ponds, lakes and other bodies
of water. Stay away from objects that conduct electricity such as barbed wire fences, power
lines, windmills, etc. Thank you for listening to this brief presentation
on lightning safety. We hope you keep these safety tips in mind as we move into the spring
and summer months and begin enjoying the great outdoors. Stay safe out there, and please
remember, when thunder roars, go indoors!