Supercells are a rare occurring weather phenomenon related to thunderstorms.
What is a Supercell?
Supercells are an extreme thunderstorm. They are rare because they need a lot of energy to form. Hail the size of baseballs and tornados may accompany a supercell. They are formed when an updraft, which is when warm, moist air rises, condenses within a thunderstorm. A wall cloud is usually formed below the rest of the storm which gives it a chance to form a tornado. Downdrafts are made of colder air and make gusts of wind that go towards the ground. These can destroy trees and buildings. A wind shear is a type of wind which can change direction quickly and causes the split between the downdraft and the updraft within the the storm. If there is a rotating wall cloud and it is persistent, that may mean that a tornado will form.
How do Supercells Form?
Supercells need a variety of atmospheric conditions to form. They need at least 50% humidity at sea level to form a supercell thunderstorm. A tornado needs to have at least 55% humidity. This does change due to elevation. Supercells also need instability and lift within the atmosphere for it to form. When the air at the surface is warmer than the air above it, the atmosphere becomes unstable. The faster the air rises, the more unstable the atmosphere is. The last condition a supercell needs to form is a wind shear which creates a horizontal vortex and is tilted upwards by a thunderstorm updraft, creating the deep updraft supercells require.
What are the Types of Supercells?
There are three types of supercells. One kind of supercell is called a Classic Supercell which can be powerful on rare occasions. A Classic Supercell produces the most tornados and an average amount of rain from the rear of a forming downdraft. Another type of supercell is called a High Pressure Supercell which is more devastating because it has a torrential rain downpour from the forming downdraft. The tornados that these supercells create are obscured by rain and you never know it is there. High Pressure Supercells are darker compared to the others and produce the most rain and hail. The last type of supercell is called a Low Pressure Supercell. This kind of supercell is one that creates an amazing spectacle and because of this it is often used in photography. This type of supercell creates the most hail and can be completely transparent on rare occasions.
During a supercell the same precautions are taken as if there was a tornado or a lightning storm. This includes moving to the cellar, basement or any underground area in your house and turning off all the electricity so that it will make you less of a target for the lightning strike.
The variety of supercells that occur in the world are formed in a simmilar fashion and caution needs to be taken if they appoach.