Severe Storms in the Midwest


Types of Storm Cells


Single Cell Storm- These storms, hence the name, consist of one cell. They do not usually produce severe weather, though it can happen. Most of the severe weather that come from these storms is made by micro-bursts and down-bursts. The only things severe are the winds and heavy rainfall, light hail, and rarely, an extremely weak tornado. Single celled storms only last for 20-30 minutes if not shorter.


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Multicelled Storms- Multicelled storms are the most common out of all of the storm types. These storms consist of many cells in either a multicell-cluster or a multicell-line. The strongest precipitation cell in a multicell-cluster is the highest cloud, which it can produce moderately heavy rainfall. On the other hand, the strongest cell in a multicell-line is usually in the middle with weaker cells surrounding the stronger one. Multicell storms can produce occasional flash floods with heavy precipitation, moderate hail, winds from down-bursts, and a weak tornado.


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Multicelled Cluster




Supercell storm
A supercell storm is by far the most severe, and rarest out of the four. It has a deep rotating updraft, which makes this storm different from all of the rest. This cycling updraft is called the mesocyclone. Though a mesocyclone is one of the key ingredients of a tornado, there are some factors from keeping some of these massive storms from producing one of these monsters.
These storms are extremely dangerous in their conditions. They can produce large hail, flash floods, extreme precipitation, strong winds, and weak to violent tornadoes.


Structure of a super cell

Like most storms, super cells are made of separate parts. To begin with, the anvil. The anvil is given its name due to the shape of the cloud that deeply resembles an anvil. It is extremely cold, and holds some of the moisture of the storm that is transported from the bottom of the troposphere towards the top. This really helps forecasters determine the direction the storm is going, and how fast it is moving due to the light density which allows wind to move it along easily.
The Flanking line is created by the combining of the outflow boundary into warm and moist air. It is seen as the line of cumulus clouds near the front of a supercell. The clouds nearest the storm may eventually merge into the parent storm, thus becoming the storm itself. It usually feeds into the updraft.
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Supercell Storm
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Severe Lightning




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Tornado on the Ground

Severe Conditions

Lighting

The phenomenon lightning is the expulsion of electricity which is followed by thunder. The ingredients needed in order for lighting to occur include wind, friction, humidity, and pressure from the atmosphere. Ice within the clouds may also be essential to the formation, as the ice crystals might be the key element for the separating of the positive and negative charges. Due to the severity and heavy rain fall of super cells, cloud to ground lightning is common. Lightning can travel up to speeds of 130,000 and reach staggering temperature of up to 54,000 degrees F.

Hail/Rainfall

As we all know, rain is a liquid form of precipitation that comes from the formation of clouds. Rain requires the atmosphere to be in conditions that are right for water to be stable, in other words liquid form. Air also has to be saturated enough in order for rain to be able to be able to fall to the ground without evaporating. The precipitation Virga helps add water to the air by falling and being evaporated back into the atmosphere. Always be on the look out for rising waters if you live in a flood prone area. Get to higher ground as soon as you hear of heavy rainfall. It's best to be prepared rather than suffer the consequences. On the other hand, hail is the solid form of rain. Hail formation is only possible with a strong updraft of air from the parent thunderstorm (similar to the conditions of a tornado) and is usually formed in a severe thunderstorm. It needs a slightly lower temperature in order for the solid cast to form. The sizes of hail can range from .20in to 5.9 inches around. To put this into a better perspective it can range from the size of a pea to the diameter of a computer CD.
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High Flood Waters

Tornadoes
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Hail damage

When a severe storm has the right conditions, they might be able to produce one of the most deadliest wind structures know to the world, tornadoes. These forms of destruction are caused only when the conditions are perfect. As most people know, the air must be warm and moist accompanied by eastward movement of wind. The clash of cold, dry air and the warm, moist air is only one of the key facts needed to create the right environment for a tornado. Many of the facts are still unknown to meteorologists, and that is why they are studying all they can about these deadly wind storms. However, we do know that these certain essentials are needed to create the perfect environment. First of all, tornadoes cannot form but only in a low pressure atmosphere, accompanied by a cold front in order for the moist air to travel upward. After the formation of the thunder cloud (only if the atmosphere is in an unstable condition [which is caused mostly when dry air is on top of the most air near the surface of the Earth]) the presence of not only strong winds, but the high turning clockwise of air is also needed.

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Tornado
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Safety Kit
Where do these conditions occur?

All of these conditions that were listed can happen almost anywhere in the world. (with the exception of polar/tundra regions) All throughout the united states, regions everywhere have experienced some form of severe weather. Though in some places more often then others, these circumstances can happen almost anywhere. However, in specific areas such as the central regions of the US, experience severe storms the most out of all other places. This area is nicknamed tornado alley. Around parts of Oklahoma, Kansas, Texas, Florida, and Illinois lay areas that endure more tornadoes and severe weather than anywhere else in the united states. tornadoUSmap.gif

Safety and Precautions

Do not take severe weather lightly. Many deaths have been caused by the unpreparedness of people under these circumstances. One of the first rules of safety in sever weather, is to find some sort of shelter immediately. Some types of shelter only exist during certain conditions. A trailer/car does not provide the adequate amount of shelter during a tornado (They are even more dangerous to be in during tornadoes), therefore you must leave them in order to get to safety. However during a severe thunderstorm (those of which that DO NOT produce tornadoes) it is safest to stay in these structures in order to prevent electrocution from lighting and the possibility of hail. One should store all essentials needed to survive if they live in tornado prone areas. Water, non-perishable food, medicenes, first-aid kits, and special essentials are the most important things needed. Never try to outrun tornadoes, for that is one of the leading causes of death from tornadoes. Instead, leave the car and find a ditch or crevice in the ground and get into a position in which your arms are covering your head. It is usually not the tornado itself that kills, but the debris. Have plans and be prepared.

Websites Used for Information

http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/svr/type/spr/home.rxml

http://www.theweatherprediction.com/severe/structure/
http://en.wikipedia.org/wiki/Lightning
http://www.nssl.noaa.gov/edu/safety/tornadoguide.html
http://www.weather.com/encyclopedia/tornado/form.html
http://en.wikipedia.org/wiki/File:Globdisttornado.jpg