Atmosphere And Weather

How a Thunderstorm Forms

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"How a Thunderstorm Forms"
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There are three things needed for a thunderstorm. One is moisture in the air to form clouds and rain. Two, unstable air is warm air that rises rapidly. The third component of a thunderstorm is 'lift'. Lift factors include sea breezes, weather fronts, and mountains, which lifts air to form thunderstorms.

Most thunderstorms occur during the spring and summer months. There are times when thunderstorms develop during the winter and fall months. Most thunderstorms occur during the afternoon along the Gulf Coast, southeastern and western states. In the Plains states, thunderstorms usually occur during the late afternoon or at night. An example of a winter thunderstorm with lightning happened during a 1993 blizzard in Washington, D.C. The lightning caused power outages.

How Thunderstorms Form

First Stage or Developing stage has very little rain. Fluffy cumulus clouds indicate that the moist air is rising. The sky begins to darken, and occasionally lightning strikes but there is no thunder.

Second stage or Mature stage the sky looks black, and sometimes, dark green. Hail develops during this stage. Hail forms when strong rising currents of air within a storm (“updrafts,”) carry droplets of water to a height where the water freezes. The ice particles grow in size until they are too heavy for the updraft to hold and the hail falls to the ground. Large hailstones fall at speeds of 100+ miles per hour. That is why damage from hailstones is prevalent.

Strong winds occasionally develop that can destroy plants or tree branches. Tornadoes also form during this stage of the thunderstorm. Thunder and lightning are the most prevalent at this time.

The National Weather Service (NWS) defines lightning as the product of rising and descending air within a thunderstorm that separates positive and negative charges. Rain water and ice particles affect the electrical charge. The accumulation of negative and positive charges and electrical energy causes the electrical discharge. The flash and electrical power of lightning have enough power to light a 100 watt light bulb for three months or more. The air of a lightning strike heats to 50,000 degrees F. This is hotter than the surface of the sun. The cooling of the air is rapid. The rapid heating and cooling of air (literally a shock wave) causes thunder.

The third and final stage of the thunderstorm is the dissipating stage. Rainfall decreases. More intense wind bursts may occur. Lightning strikes are still dangerous at this time.

Most thunderstorms do not last more than an hour or so during the three stages. The mature stage has the longest time element.

Thunderstorms can cause a lot of damage to people, plants and animals in a short amount of time.

More about this author: Nan C Avery

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