range category indicator is on. wait for 3 seconds and this range will be entered in the
computer.
To change the range repeat this process.
Facts about Lightning and Thunderstorms
The average lightning strike is 5-6 miles long A lightning strike is incredibly powerful;
up to 30 million volts at 100,000 amps flow in less than 1/10 of a second.
Thunderstorms and the associated lighting cause an average of 200 deaths and many
more injuries in the U.S. every year. Most of these deaths and injuries could be
prevented by the warning provided by Field Pro.
The average thunderstorm is 6-10 miles wide and moves at a rate of 25 miles per
hour.
Once the leading edge of a thunderstorm approaches to within 10 miles, you are at
immediate risk due to the possibility of lightning strikes coming from the storm’s
overhanging anvil cloud. This is the reason many lightning deaths and injuries occur
with clear skies overhead.
On average, the thunder from a lightning strike can only be heard over a distance of
3-4 miles, depending on the terrain, humidity and background noise around you. By
the time you can hear the thunder, the storm has already approached to within 3 - 4
miles.
The sudden cold wind that many people use to gauge the approach of a thunderstorm
is the result of down drafts and usually extends less than 3 miles from the storm’s
leading edge. By the time you feel the wind, the storm can be less than 3 miles away.
Approximately 100,000 thunderstorms occur in the U.S. each year. About 10% of all
thunderstorms are severe enough to produce high winds, fl ash fl oods and tornadoes.
IMPORTANT
There are two types of lightning produced by a thunderstorm, cloud-to-ground and
cloud-to-cloud. For any user on the ground, the cloud-to-ground is the most dangerous. The
Field Pro is designed to detect cloud-to-ground lightning strikes. While it may detect cloud-
to-cloud lightning strikes, there may be occasions where storms will produce cloud-to-cloud
lightning strikes that are not detected by the Field Pro. User should therefore still exercise
extreme caution when exposed to lightning storms.
