High wind warnings headed your way? A thunder storm might be brewing. Turns out, the loud crashes of thunder and bright bolts of lightning are just what we see on the surface. Behind the scenes there is a complicated weather phenomenon.
Whether it’s a severe thunderstorm warning or just a few heavy showers, here’s everything you need to know about thunderstorms from how they form to when your region is most likely to be affected.
How do thunderstorms form?
A thunderstorm is the result of something called a convection cell, which occurs when warm, wet air or water vapor rises into colder air causing the vapor to condense into water droplets. The cool air drops, warms and rises again. A small form of this cycle results in a cloud, but if it occurs with large amounts of air a thunderstorm can be sparked.
What causes a thunderstorm?
There are three main ingredients: unstable air, lift and moisture. Unstable air means there is warm, wet air near the surface and dry, cold air just above it. To create the storm, that air must be lifted. Lift occurs when the warm, less dense air rises, displacing the colder air above it. In a thunderstorm that warm air is also wet. This moisture often comes from the ocean, especially if there are warm currents which result in increased evaporation.
When are they most common?
Thunderstorms can occur year-round, 24-hours a day, but they are most common in spring or summer during the afternoon and evening. This also varies depending on where you live! In western and southwestern states and along the Gulf Coast, storms are likely to happen during the afternoon. In the plains states a storm is more common in late afternoon or evening.
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What are the categories of thunderstorms?
there are four main types of thunderstorms, each classified by the quantity and behavior of their convection cells. The first and most simple is an ordinary cell storm, which consists only of one cell. There are also multi-cell cluster and multi-cell line storms, both made up of a group of cells but differing in shape as indicated by the name. The final category is the supercell stormwhich is the most dangerous, and forms when there is a mesocyclone or updrafts within the cell that spiral as the air travels upward.
What is thunder?
That sometimes-frightening clap heard in the midst of a storm is actually the sound of air expanding. When lightning strikes the shock travels from the clouds to the Earth’s surface and then back again. With that return path, the air surrounding the bolt heats up so much it explodes outwards, compressing the other air only to expand, cool and contract again creating a loud shock we can hear from the ground: thunder.
What is lightning?
Thunder’s sky-brightening partner is actually a giant spark of electricity. It occurs when the opposite charges exist between clouds or a cloud and the ground build up so much that the air cannot act as an insulator anymore and there is a rapid discharge of electricity. The air is then neutralized for awhile until the charges build up once more and you see another bolt.
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How does a thunderstorm stop?
When the downward drafts in a cell become stronger than the warm air moving up a storm will start to slow. With limited warm, moist air moving upward, the cloud droplets cease to form, ushering in a light rain as the storm peters out.
Why do most thunderstorms happen at night?
In the US many thunderstorms actually occur in the afternoon, when the surface is the warmest. Further inland, storms may occur later as warm, moist air travels in from the coastlines.
How long does a thunderstorm last?
The lifespan of a storm is typically not longer than an hour.
Where does it thunderstorm the most?
The southeastern states in the US have the most thunderstorms per year as a result of the warm and wet winds coming in from the Gulf of Mexico. Florida is particularly known for its thunderstorms and holds the record for the number of thunderstorm days per year.
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What is the longest thunderstorm ever recorded?
The longest thunderstorms are supercell systems. There is limited data on the longest ever storm, however in 1979 Tropical Storm Claudette hit Houston, Texas, dropping 42 inches of rain in just 24 hours. This remains the world record for the highest rainfall over flat land in a 24-hour period.
www.usatoday.com
George is Digismak’s reported cum editor with 13 years of experience in Journalism