A cloud is formed and grows at the height. As long as the air package from the ground is warmer than the ambient air at height. If there are really good conditions, the cloud peak will still reach the tropopause. Which during the summer is about one mile in height. At that height it can be 50 degrees cold so the cloud peak consists entirely of ice particles. That flow out in the direction of the wind and cause the cloud to resemble an anvil.
The strongest part of the flash discharges
Between ground and clouds during thunderstorms normally goes from the ground up to the cloud. The main discharge pushes upwards by up to one third of the light speed, about 100,000 kilometers per second.
When the rain and hail left the cloud, different charges rapidly arise with over and shortages of positive. Ond negative charges and to “compensate” this happens discharges, – we see this as lightning.
The flash in turn is the visible result. Of the air being heated up so strongly as the speed is terribly fast. The flash itself is only 2-3 cm wide, – while the light street can be 10-meter wide.
The mole is caused by the air being expelled. And expanding by the heat at a rate that exceeds the sound several times! Since the flash extends over several kilometers, the mule is usually extracted and can sound like when “tearing paper”. If the flash hits a distance of less than 500 m. However, a sharp violent bang is experienced, with subsequent violent noise and heavy vibrations.
The “zick-zack” pattern of the flash is due to the fact that the flash is usually (but not always) “comfortable”, which means that it searches for a path with the least resistance (= high ionicity), – therefore. The path of the flash gate will not be the shortest, but also the most convenient.
The voltage difference between ground and clouds can be several hundred million volts. And the current in the main discharge itself is several tens of thousands of amperes. In some cases several hundred thousand amperes.
The flash always goes down in the same place
Before the main discharge can take place, a road must be built, a flash channel. This is done by charging “feels” through the air in stages of type 30 meters through so-called shock ionisation. Since the charges in advance do not know which path will be the easiest. The jump occurs several different directions, which causes the flash to look like an up. And nervous tree with several “branches” closest to the cloud underside.
The whole thing that we perceive as a lightning strike. With precharge and main discharge, takes a couple of tenths of a second. Sometimes one or more consecutive flashes are included which follow the same path in the air. The noise that is heard occurs when the air is heated in an instant up. To 30000 degrees or more of the flash and with a blast expanding in all directions.