Thunderstorms

How do Thunderstorms Develop?

THUNDERSTORMS ARE SMALL STORMS THAT FORM FROM THE STRONG UPWARD MOVEMENT OF HOT, HUMID, UNSTABLE AIR.    Under these conditions, when hot humid air rises it forms CUMULONIMBUS CLOUDS - THE ONLY TYPE THAT PRODUCES THUNDERSTORMS. If the air is hot and humid enough it rises really fast making the air in the cloud highly unstable, and can generate lightning.

What is Lightning?

lightning_forms.gif

Friction between the dust and ice particles within the cloud generates an electrical charge.  Positively charged particles accumulate in the top of the cloud, and negatively charged particles build up in the bottom of the cloud.  WHEN THE DIFFERENCE IN CHARGE BETWEEN THE CLOUD AND THE GROUND IS GREAT ENOUGH, AN ELECTRICAL CURRENT FLOWS BETWEEN THEM...AND WE SEE LIGHTNING!

Most lightning occurs within a cloud, but they sometimes strike the Earth.  If positive charges build up on Earth surface a current can form from the Earth to the cloud.

Lightning, like all electricity, is very dangerous.  During a lightning storm it is obviously a bad idea to be outside, but if you find yourself out during a lightning storm make sure you are not the tallest thing around!

All electrical currents, including lightning, take the path of least resistance, meaning they go the most direct route from one charge to the opposite charge.  If you are the tallest thing around during a lightning storm you make yourself the shortest path.  Avoid trees, and other tall objects to stay safe.  

What is Thunder?

The electrical discharge of lightning generates incredible energy in the form of electricity, light and heat.  A typical lightning strike is 28,000 degrees Celsius!

THIS INCREDIBLE HEAT CAUSES THE AIR AROUND THE LIGHTNING BOLD TO EXPAND RAIPIDLY, CREATING A VACUUM IN ITS PATH. 

AFTER THE LIGHTNING PASSES, THE AIR COLLAPSES BACK IN ON ITSELF CREATING A HUGE BOOMING NOISE WE CALL THUNDER.

 

Types of Thunderstorms

Air Mass Thunderstorms

Air mass thunderstorms are small isolated storms located in the middle of an mT air mass.  

They typically last for around one hour before breaking up.

Frontal Thunderstorms

Frontal thunderstorms develop in the warm air directly ahead of a cold front.  They develop in a huge long line called a squall stretching over much of the length of the front itself.  Because they are all together, frontal thunderstorms are much more severe and longer lasting.