- Written by Tim Howard
- Hits: 2955
All thunderstorms are dangerous. Every thunderstorm produces lightning. While lightning fatalities have decreased over the past 30 years, lightning continues to be one of the top three storm-related killers in the United States. In 2010 there were 29 fatalities and 182 injuries from lightning. Although most lightning victims survive, people struck by lightning often report a variety of long-term, debilitating symptoms.
Other associated dangers of thunderstorms include tornadoes, strong winds, hail and flash flooding. Flash flooding is responsible for more fatalities – more than 140 annually – than any other thunderstorm-associated hazard. Dry thunderstorms that do not produce rain that reaches the ground are most prevalent in the western United States. Falling raindrops evaporate, but lightning can still reach the ground and can start wildfires.
THUNDERSTORMS AND LIGHTNING.
A thunderstorm is defined as a storm that contains lightning and thunder which is caused by unstable atmospheric conditions. When the upper air which is cold sinks and the warm moist air rises, storm clouds or ‘thunderheads’ develop resulting in thunderstorms. This can occur singularly, in clusters or in lines. Severe thunderstorms can bring in heavy rains which can cause flash floods, strong winds, lightening, hail and tornadoes.
The National Weather Service defines a thunderstorm as severe if it contains hail that is three quarter of an inch or the wind gusts are at 58 mph or higher. These storms are constantly monitored by the National Weather Service Storm Prediction Center in Norman, Oklahoma. A warning is issued by this center to the areas where the severe thunderstorm or a tornado is predicted.
The type of cloud which is usually responsible for thunderstorms is ‘cumulonimbus’ (a Latin word which translates to ‘rain heaps’). These types of clouds can span the entire troposphere and can be more than 12 miles high. During extreme storms, the updrafts can reach as high as 100 mph while the downdrafts can be even higher. Aircrafts totally avoid these types of clouds as the turbulence found inside them are usually on the extreme side.
It has been estimated that are nearly 16 million thunderstorms annually all over the globe. In the United States, Florida ranks first with a 100 thunderstorms days annually. Across the globe, Kampala, Uganda holds the record of about 240 thunderstorm days annually.
Types of Thunderstorms.
Once upon a time the thunderstorms were classified simply as light and severe. However, with an increase in understanding and better equipment, thunderstorms are now classified into the following four categories based on the physical characteristics of the storm:
- Single Cell Thunderstorms: have a lifespan of about 30 minutes and are not severe. The storms of this kind are rare and as these occur randomly, they are very difficult to forecast.
- Multi-cell Cluster Storm: are the most common type of thunderstorms and occur in a group. Storms of this kind can persist for a few hours and can produce moderate sized hail and weak tornadoes.
- Multi-cell Line Storm: consists of a long line of thunderstorms that can produce hail the size of golf balls and weak tornadoes. Storms of these kinds can easily be predicted with the help of radar.
- Super-cell Storms: although rare are highly organized thunderstorms. Storms of this kind pose a high threat to life and property as these can produce strong to violent tornadoes.
Here are some interesting thunderstorm facts:
- There are about 1800 thunderstorms occurring at any moment across the world.
- All thunderstorms produce lightening which often strikes outside of the area where it is raining and is known to fall more than 10 miles away from the rainfall area.
- A severe thunderstorm can produces winds that can cause as much damage as a weak tornado and these winds can be life threatening.
- Further, thunderstorms of this degree can produce hail that can be three-fourth of an inch in diameter that fall at a speed more than 100 mph. Hailstones of this size cause more than $1 billion damage of properties and crops annually.
- We all know that light travels faster that sound and this is the reason as to why we can see the lightening before we hear the thunder. To calculate the distance that you are away from the thunder, count the seconds that has passed between a lightning and the next sound of thunder and divide the duration by five. The result will give you the distance in miles.
Some thunderstorms can be seen approaching, while others hit without warning. It is important to learn and recognize the danger signs and to plan ahead. In the United States, lightning kills 300 people and injures 80 on average, each year. All thunderstorms produce lightning and all have the potential for danger. Those dangers can include tornadoes, strong winds, hail, wildfires and flash flooding, which is responsible for more fatalities than any other thunderstorm-related hazard.
The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Nearly 1,800 thunderstorms are occurring at any moment around the world. That’s 16 million a year!
Despite their small size, all thunderstorms are dangerous. Every thunderstorm produces lightning, which kills more people each year than tornadoes. Heavy rain from thunderstorms can lead to flash flooding. Strong winds, hail, and tornadoes are also dangers associated with some thunderstorms.
Lightning's risk to individuals and property is increased because of its unpredictability, which emphasizes the importance of preparedness. It often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall. Most lightning deaths and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.
- Average 93 deaths and 300 injuries each year
- Causes several hundred million dollars in damage to property and forests annually.
- Straight-line winds.
- Winds can exceed 100 mph!.
- One type straight-line wind, the downburst, can cause damage equivalent to a strong tornado.
- Large Hail.
- Causes nearly $1 billion in damage to property and crops annually
- Costliest United States hailstorm: Denver Colorado, July 11 1990. Total damage was $625 million
- Flash Floods/floods.
- The number ONE thunderstorm killer nearly 140 fatalities each year
- Most flash flood deaths occur at night and when people become trapped in automobiles
Thunderstorms need three things:
- Moisture—to form clouds and rain.
- Unstable Air—relatively warm air that can rise rapidly.
- Lift—fronts, sea breezes and mountains are capable of lifting air to help form thunderstorms.
Thunderstorms are most likely to occur in the spring and summer months and during the afternoon and evening hours, but they can occur year-round and at all hours of the day or night. Thunder and lightning can sometimes even come with a snowstorm!
Thunderstorm Watch and Warnings.
A severe thunderstorm watch is issued by the National Weather Service when the weather conditions are such that a severe thunderstorm is likely to develop. (A severe thunderstorm has winds at least 58 miles per hour or hail at least three-fourths of an inch in diameter.)
A severe thunderstorm warning is issued when a severe thunderstorm has been sighted or indicated by weather radar. A warning is more severe than a watch.
Thunderstorms may occur singly, in clusters, or in lines.
Some of the most severe occur when a single thunderstorm affects one location for an extended time.
Thunderstorms typically produce heavy rain for a brief period, anywhere from 30 minutes to an hour.
Warm, humid conditions are highly favorable for thunderstorm development.
About 10 percent of thunderstorms are classified as severe—one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.
Who’s Most at Risk from Thunderstorms?
People who are outdoors, especially under or near tall trees
People who are in or on water
People who are on or near hilltops
People who are in automobiles when flash flooding occurs near them
People who are in mobile homes and automobiles
Remember the 30/30 Lightning Safety Rule: Go indoors if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay indoors for 30 minutes after hearing the last clap of thunder.
1) Seek refuge in a building, inside a car is safe; unless it is a convertible car.
2) Inside a building don't use your phone unless for emergency.
3) If outside and you can't find a shelter here is what to do: Avoid to stick out like a sore thumb by being the tallest point of your surrounding environment. Ex; being on top of a mountain or in a flat field or in a small boat. If you are in a big boat stay inside. In a field lay down on your stomach. Don't go near any motorcycle, golf cart and drop your golf club.
4) Stay away from fences or any metallic tubes or cables or lone tree in an open field, this tree will attract lightning. In an open field don't seek shelter in an isolated shack. In a forest seek shelter in lower ground under heavy brush. In the country seek shelter in a *ravine or valley and beware of heavy rain which will flood gullies. In the middle of field if you suddenly feel your hair rising sure sign that a lighting will strike, throw yourself on your knees, your hands on your knees, don't lay flat on the ground.
5) Victims of lightning bolts will suffer a terrible electrical shock that can give them burns but not ALWAYS. They are not however carrying electricity thus can be safely attended. It is even possible to reanimate someone that you may think was killed by the lightning. If there was a group of persons that was hit, then bring help first to those who seem dead.
6) According to the Red Cross when a victim does not breath you MUST give her the artificial respiration mouth to mouth at the rhythm of one blow per 5 seconds and 3 seconds for kids* till a doctor comes along. THIS MUST BE DONE IMMEDIATELY.
7) Victims who are only stunned by the shock `still have to be attended they can suffer from burns at the fingers, toes near their belt or under their jewelries.
- Written by Tim Howard
- Hits: 1925
A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm (or sometimes as a result of a hurricane) and produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly. The damage from a tornado is a result of the high wind velocity and wind-blown debris. Tornado season is generally March through August, although tornadoes can occur at any time of year. They tend to occur in the afternoons and evenings: over 80 percent of all tornadoes strike between noon and midnight.