Technically, there is none. In general, the term "thundershower" tends to denote a fairly weak storm with light to moderate rainfall and low levels of lightning activity. However, there are no defined parameters that distinguish between a thundershower and a thunderstorm.
In fact, in order to avoid confusion, we in the National Weather Service do not use the term "thundershower". If a shower is strong enough to produce lightning, even just one single bolt, it's called a thunderstorm. Top
This is a seemingly simple question, but there is no single answer that fits everyone. The odds of being struck vary from person to person because they depend on several factors. The most significant are:
Geographical location and climatology
Diurnal and annual climatology
Personal lifestyle/hobbies
Where there is a lot of lightning, there is an increased chance of being struck. The central Florida peninsula from Tampa Bay to Cape Canaveral has the highest lightning concentration in the United States. More than 90% of the lightning in this area occurs between May and October, between the hours of noon and midnight.
During this time of day and year, people in Central Florida who spend a large portion of their lives outdoors (e.g. construction workers, park rangers, golfers, campers etc.) are more likely to be struck than anywhere else in the country. On the other hand, thunderstorms are uncommon in the Pacific northwest, and are virtually unheard of during the winter months.
People in this region who spend much of their lives indoors (e.g. shopkeepers, librarians, bowlers, billiard players, etc.) might win the lottery before they were struck by lightning. It is impossible to assign one single probability to every person in every situation.
There are NO SAFE PLACES outdoors during a lightning storm. Don't kid yourself--you are NOT safe outside. Following these tips will not prevent you from being struck by lightning, but may slightly lessen the odds.
If camping, hiking, etc., far from a safe vehicle or building, avoid open fields, the top of a hill or a ridge top. Keep your site away from tall, isolated trees or other tall objects. If you are in a forest, stay near a lower stand of trees.
If you are camping in an open area, set up camp in a valley, ravine or other low area. Remember, a tent offers NO protection from lighting. If you are camping and your vehicle is nearby, run to it before the storm arrives.
Stay away from water, wet items such as ropes and metal objects, such as fences and poles. Water and metal are excellent conductors of electricity. The current from a lightning flash will easily travel for long distances.
Lightning struck and traveled down the flag of a golf green. The bolt then branched out along the ground leave dead grass as an indicator of the ground current.
NO! Lying flat on the ground was once thought to be the best course of action, but this advice is now decades out of date.
When lightning strikes the earth, it branches out along the ground. The lightning bolt can be fatal up to 100 feet away from the point of strike.
These currents fan out from the strike center in a tendril pattern, so in order to minimize your chance of being struck, you have to minimize BOTH your height AND your body's contact with the earth's surface. Top
Lightning struck the pole and traveled down the flag to the golf green. The bolt then branched out along the ground leave dead grass as an indicator of the ground current.
We don't recommend the crouch because it will not significantly lower your risk of being killed or injured from a nearby lightning strike.
Be aware of your situation and PLAN AHEAD. If you going to be involved in an outdoor activity, make sure you know what the forecast is, ESPECIALLY if you live in a lightning prone area. If storms are forecast, have a plan of action that you can enact quickly to reduce your chances of being struck. Top
An entire lightning strike employs both upward and downward moving forces. However, the return stroke of a lightning bolt travels FROM THE GROUND INTO THE CLOUD and accounts for more that 99% of the luminosity of a lightning strike. What we SEE as lightning does indeed travel from the ground into the cloud. Top
In photographs, it may APPEAR that lightning is descending from the cloud to the ground, but in reality, the return stroke is so brilliant that as it travels up the strike channel, it illuminates all of the branches of the stepped leader that did not connect with a streamer. Top
Almost all lightning will occur within 10 miles of its parent thunderstorm, but it CAN strike much farther than that. Lightning detection equipment has confirmed bolts striking almost 50 miles away. Top
YES! If a bolt strikes your house or a nearby power line, it CAN travel into your house through the plumbing or the electric wiring! If you are using any electrical appliances or plumbing fixtures (INCLUDING telephones and computers), and a storm is overhead, you are putting yourself at risk! FACT: About 4-5% of people struck by lightning are struck while talking on a corded telephone. Top
Absolutely! While rubber is an electric insulator, it's only effective to a certain point. The average lightning bolt carries about 30,000 amps of charge, has 100 million volts of electric potential, and is about 50,000°F.
These amounts are several orders of magnitude HIGHER than what humans use on a daily basis and can burn through ANY insulator (even the ceramic insulators on power lines!)
Besides, the lightning bolt may just have traveled many miles through the atmosphere, which is a good insulator. Your ½" (or less) of rubber will make no difference. Top
Install a lightning protection system and make sure your insurance covers lightning damage. Lightning tends to strike the tallest object and boats on the open water fit this profile to a tee. Lightning protection systems WILL NOT prevent your boat from being struck, but they can help minimize the damage. Top
Lightning rods will not prevent your building from being struck. Rather the purpose of lightning rods is to intercept a lightning strike, provide a conductive path for the harmful electrical discharge to follow (the appropriate UL-listed copper or aluminum cable), and then disperse the energy safely into the ground (grounding network).
While lightning rods help protect a structure, and you, from a direct lightning strike, a complete lightning protection system is needed to help prevent harmful electrical surges and possible fires caused by lightning entering a structure via wires and pipes.
A complete system also includes electrical surge protection devices for incoming power, data, and communication lines; and surge protection devices for vulnerable appliances. Lightning protection may also be needed for gas piping. Top
It depends. Do you have electrically sensitive equipment and do you think your building may be struck? Contrary to some popular beliefs, lightning protection systems DO NOT prevent lightning.
Instead, they actually bank on the assumption that your building will be struck. They help mitigate damage by giving the lightning a preferred pathway into the ground, not unlike a flood spillway system. Top
