Large hailstones fall at speeds faster than 100 mph. The action of rising and descending air within a thunderstorm separates positive and negative charges. Water and ice particles also affect the distribution of electrical charge. Lightning results from the buildup and discharge of electrical energy between positively and negatively charged areas. The average flash could light a 100-watt light bulb for more than 3 months.
Most lightning occurs within the cloud or between the cloud and ground.
Your chances of being struck by lightning are estimated to be 1 in 600,000 but could be reduced by following safety rules. Most lightning deaths and injuries occur when people are caught outdoors. Most lightning casualties occur in the summer months and during the afternoon and early evening. The rapid heating and cooling of air near the lightning channel causes a shock wave that results in thunder. Many fires in the western United States and Alaska are started by lightning.