2. Thunderstorms are classified into four major types, namely the supercell, squall line, multicell single cell. The strongest type is called the supercell, which can be as wide as 24 kilometers.

6. http://www.weatherimagery.com/blog/positive-negative-lightning/

7. Why does lightning occur? The charge buildup in thunderclouds are unstable. When electric fields generated by the charge buildup become too strong (typically 3-4 kilovolt/cm at the altitude of the negative charge region of the cloud) electrical breakdown of the air occurs and charge is exchanged within the cloud or to the ground. Charge is exchanged by a lightning flash. Intracloud Cloud-to-cloud Cloud-to-air Cloud-to-ground

8. * Types of Flashes Cloud-to-ground lightning is a discharge between opposite charges in the cloud and on the ground. Cloud-to-ground lightning can either occur between negative charges in the cloud and positive charges on the ground (a negative flash) or between positive charges in the cloud and negative charges on the ground (a positive flash). Source : http://www.lightningsafety.noaa.gov/science_types_flashes.htm Intra-cloud lightning is an electrical discharge between oppositely charged areas within the thunderstorm cloud.

10. Positive flashes are more common in winter storms. ? The apparent cause of this is the lower freezing level, which places the positive charge center closer to the ground, thus increasing the likelihood of a flash.

11. The stepped leader is a small packet of negative charge that descends from the cloud to the ground along the path of least resistance. In its path, the leader leaves a trail of ionized gas. It moves in steps, each typically tens of meters in length and microseconds in duration. After a step, the leader pauses for about 50 microseconds, then takes its next step. The leader charge packet sometimes breaks up to follow different paths, giving lightning its forked appearance.

12. If additional negative charge is immediately available in the cloud in the vicinity of the initial return stroke, the additional charge may start to move toward ground in the conductive path left by the initial return stroke. these subsequent leaders are called dart leaders.

14. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/lightning2.html

15. Lightning is 50,000° F - three times as hot as the Sun.Lightning is only 1 inch in diameter. Lightning has been observed over 100 miles long. An average lightning flash has the energy of a 1-kiloton explosion. Lightning voltage can be up to 300 million volts. Lightning current averages 30,000 amps, but ranges from 10,000 to 200,000 amps - 100 To 1,000 times as strong as a steel welder.