Our local weather station reports the number of lightning strikes during storms and notes how many strikes are "positive" or "negative." What's the difference?
—Bill Ackerman, Homosassa, Fla.
Negative lightning, which accounts for about 95 percent of all strikes, transfers a negative charge from the cloud to the ground. Positive lightning transfers a positive charge and is nearly always far stronger. According to the National Oceanic and Atmospheric Administration, positive lightning may discharge as much as 300,000 amperes and generate 1 billion volts of current. It is believed to cause a large percentage of forest fires and other major damage.