|GENERAL THUNDERSTORM HAZARDS
METEOROLOGIST JEFF HABY
Five areas of interest will be covered in this writing on general thunderstorm hazards including:
2. Visibility, Slick Roads
3. Roof Damage
4. Wind Damage
5. Water Damage
Lightning is one of the primary killers from thunderstorms. Lightning does not require a severe thunderstorm warning. ANY storm can
produce lightning (severe or non-severe). Lightning also strikes with little or no warning. Many lightning deaths occur when it seems
the storm is “winding down and the rain has slackened or stopped”. For these reasons (produced from any thunderstorm / little or no
warning / thinking storm is over), lightning is responsible for dozens of deaths each year. Storm deaths from flooding and tornadoes
are often heard about more partially because several deaths often occur at once and the storm event is often on people’s mind. Lightning
tends to kill one person at a time (although multiple deaths at once do occur) and can occur from ordinary storms that are not on
people’s mind as much.
People commonly go outside during a thunderstorm such as to go to the car, participate in outdoor activities or to walk to another location. The
thinking can be, “getting struck by lightning is like the odds of winning the lottery… it is not going to happen to me”. This can make people
feel more comfortable when outside during a storm given that the odds are very low of getting struck. The threat from lightning can not
be visually seen like with many of the cases with other weather events (tornado seen approaching, flooding seen in road) thus the victim
has basically no time to make a decision to avoid lightning. The decision to avoid lightning has to be made before going outside or being
stuck outside. This can be difficult to do but can mean the difference between life and death since a great percentage of lightning deaths
occur outside (although a few deaths occur inside also such as when lightning travels through plumbing or electrical wire).
VISIBILITY, SLICK ROADS
Another general thunderstorm hazard is driving. The storm does not have to be severe to cause significant driving problems. One problem
with driving in the rain is visibility (VIS). Even with good windshield wipers it can be frustrating to keep constant visibility through
the changes in intensity of rain. Splashing and spraying from nearby vehicles can also reduce visibility. It is important to drive slower
and more cautiously when it is raining. Since the visibility is reduced, it is important to turn on headlights during these rainy and
wet conditions so that other drivers can see you better. Fogging up inside the car can be a problem during rain. This is because the
humidity is high and it is easy to condense moisture on glass. Be familiar with the proper and best techniques to unfog the windows
in your particular car in order to prepare for this potential problem.
An additional problem when it rains is that the roads become slicker. Water reduces friction between the tires and the road. The condition
of the tire will play a role in how significant the problem with wet roads become. It should be assumed the cars around you and your
car will have less friction with the road. This results in longer stopping distances when putting on the brakes. It also means it can
be easier to lose control of the vehicle. The problem with less road friction is another reason to drive slower and with more caution
Thunderstorms add wear and tear to a roof. It may take one storm to damage a roof or it can be the cumulative impact of storms over many
years or a combination of both. There are several ways in which the weather elements can damage a roof. They include the impact from hail,
damage from wind, thaw and freeze opening up cracks, water leaking through the rotting wood, and long term damage from the sun. Many of
these factors contribute to the roof needing to be replaced after several years. One big storm though can do the damage all at once. The
big events are large hail and severe wind. A hail storm or wind storm may be significant enough that the roof needs immediate attention
due to leaks that are opened by the hail or wind. A leaking roof will lead to continued and further damage each time it rains.
Roof damage can result in 1000s of dollars of needed repairs, thus roof replacement is big business. The proper home insurance can
substantially reduce these costs to the home owner when a replacement is needed. A new roof adds value to the home and is a primary
defense from the weather. Over many years though the weather wins and a replacement is needed.
A 58 mph wind or above is a severe wind. A severe thunderstorm warning will be issued when wind speeds are this high or greater from a
thunderstorm that has developed. Wind speed lower than this can also cause considerable damage and death. Thus, any thunderstorm is
capable of producing damage and death. One threat results from the wind blowing objects down. One of the most common objects that can
be blown down includes tree branches. Tree branches are extremely heavy and will severely damage anything they fall on. Locations with
big and tall trees are especially in danger of having trees fall on objects below. These objects can include houses and cars. The damage
produced from any one tree can result in 1000’s of dollars of damage. A person under a tree can be injured or killed by a falling limb. This
makes it very important to keep trees pruned. This reduces the chance of a weak limb falling on property or a person. Wind can also produce
damage to fencing, sheds and any fragile materials exposed to outside air. Precautions should be taken before a storm strikes such as
reinforcing fencing, putting away loose outside materials, pruning trees, and having cars safely parked.
There are several ways in which thunderstorms can produce water damage. One type of damage can be done to landscaping and gardens. The
runoff from rain will tend to flow in thin and long bands. Where the water is flowing, erosion will occur. If the soil is loose, then
this runoff will quickly erode an area. This can result in the loss of soil, displacement of soil and significant time in order to repair
Rain events can also hide pot holes in the road. With the pot holes hidden, cars will run into them causing potential damage to the car and
an enlargement of the pot holes. It is not uncommon to notice more and bigger pot holes after rain events. Wet roads can also make it more
difficult to see painted road lines and to see reflection from headlights.
Water damage also occurs when water seeps into areas that are supposed to be water proof. This can result in damage to houses, window
frames, doors and cars. It is important to check to see if a seal is maintained over time. If the seal is compromised it should be fixed
quickly to reduce damage.