What Am I?

Clue 1: I am a dangerous part of
the weather.

Clue 2: I am hotter than the surface of the sun.

Clue 3: I am a gigantic spark
of electricity.

Clue 4: You will often see me in
storm clouds.

Clue 5: Sometimes I stay in the clouds but other times I strike the earth.

Clue 6: I light up the sky during
a thunderstorm.