Thunderstorm lightning

Cause of Thunderstorm Lightning

As the thunderstorm forms, it produces ice in the upper cloud. The formation of ice in a cloud is an important element in the development of lightning. Those storms that fail to produce large numbers of ice crystals may also fail to produce lightning. Strong rising and sinking motions within the cloud are important too, as
they enhance collisions among cloud particles
causing a separation of electrical charges.
Positively charged ice crystals rise to the top of
the thunderstorm and negatively charged ice
particles and hailstones drop to the middle and
lower parts of the storm.

As the differences in charges continue to increase, positive charges rise up taller objects
such as trees, houses, and telephone poles. The
charge can also move up you, causing your hair
to stand on end! This is natures way final way of
warning you that lightning can strike very soon near you.
The negatively charged area in the storm sends out a charge torward the ground called a step leader. It is invisible to the human eye & moves in stepstorwards the ground. It takes less than a second for lightning to get close to the ground, and when it does it is attracted by all of the positively charged objects causing a channel to develop. You see the electrical transfer in this channel as lightning. There may be several repeated transfers of electricity
within the channel. These are observed as flickering lightning.