Good lightning detectors, used sensibly, greatly reduce the
risk of personal lightning strike by providing timely
warning of approaching thunderstorms.
But how real are the chances of becoming a victim of a
lightning strike?
The risks are very real, but with care and sensible safety
management they are easy to reduce.
Lightning is the second most deadly type of weather - only
floods are more lethal. On average, 600 people in the USA
will be struck by lightning each year, and 80 will die. Many
of those who survive will be severely injured, and recovery
can be long and painful.
Lightning is also unpredictable - even sneaky. While most
strikes occur close to the rain, hail and winds of a
thunderstorm, a significant proportion occur well before
or after the main part of the storm has passed. For more
information visit the Lightning page.
Strikes 10 miles (16km) or more ahead of the storm are not
uncommon, and while the storm may be visible in open
country, at this distance thunder may not be heard. These
sorts of strikes are often referred to as "bolts from the
blue"
Overall, your chances of being struck by lightning are low -
about 1 in 50,000 in the USA, which still represents better
odds than the chance of winning a lottery. Nevertheless,
the odds become much shorter if you are working outside,
playing sport, picnicking, boating or in high country when
a thunderstorm is in the area. One particular form of risk
occurs during outdoor team sports such as baseball or
soccer, where players on the field are the highest points
for several tens of yards, and are therefore the most likely
point of contact.
Imagine how devastating it would be for the coach, manager
and parents of a kids team to see someone killed or injured
by unexpected lightning during a game. There is no reason to
expose teams and supporters to this risk - any one of a
number of lightning detectors can give enough warning to
move everyone to safety, and will also indicate when it's
safe to resume.
Lightning Sensors
Lightning occurs when a large spark jumps between areas
with different electrostatic charges within or near a
thunderstorm. This spark causes radio interference, best
known as the static which interferes with AM radio
broadcasts.
In fact, your AM radio is a primitive form of lightning
sensor, but apart from some increase in intensity of the
static as the storm approaches, it gives no guide to
distance or direction.
More useful are the yard lightning detectors or sensors.
They consist of an aerial of some form, often on a pole,
connected to a receiver which can be preset to
sound an alarm when the storm is becoming a potential
threat. The frequency of strikes can be heard, and gives
a guide to the severity of the storm.
Range varies with the height of the sensor above the
ground. By following the installation instructions, you
can set it up to pick up storms at whatever distance you
feel is a sensible balance between risk and false alarm.
As a general guide, a lightning detector 5 feet (1.5m)
above the ground will detect lightning within 30 miles
(48 km). Raising the sensor to 10 feet (3m) will extend the
range to 100 miles or 160 km.
Some can be battery operated and are portable, others can
be fixed in your yard. If permanently installed, make sure
someone qualified has earthed the sensor to ground -
lightning detectors are targets too.
Lightning Detectors of this type - for example from
Stormwise
- start at $40.00 for a basic model, although useful extras
such as sirens and solar power add to the cost. The basic
sensor (LSU-10 is illustrated) has some portability, is
battery powered, and could be set up at outdoor gatherings
and sport events. Some very basic electrical skill would be
handy. For a little more money, and a lot less hassle, there
are better options if portability is needed.
But before covering portable lightning detectors, it is worth
mentioning a somewhat more robust detector which can be permanently
installed anywhere from homes to sporting venues, or fitted to a
vehicle for use with work crews at any location. This is the
FMLA-1000, available from WeatherShop. Fixed units cost $249.00,
mobile ones $349. With long lasting batteries, loud sirens, and
easy controls detectors like these would be a great investment for
any outdoor venue or sports club.
Portable Lightning Detectors
A number of portable lightning detectors take it a step
further. Most of them will only react to cloud to ground
strikes, and can give a rough idea of storm distance.
Although they won't show direction, they can pick whether
the storm is approaching or moving away.
One word of caution here. The manufacturers of lightning
detectors and trackers are generally an optimistic lot,
and things may not always work as well as they imply.
Lightning detection is not all that precise, so regardless
of whether you have a detector, don't forget to use your
eyes and ears.
There are four main portables on the market, and you will
probably want to compare your needs to their specific
features. At under $80.00, the StrikeAlert Personal
Lightning Detector will suit many requirements at a good
price. It's pocket sized, runs off an AA battery with 100
hours of power, and has a range of 40 miles (65km). The
SkyScan Lightning Detector is similar in capability,
is somewhat larger and less portable, can run off AC or a
car cigarette lighter, but retails close to $190.00
Still more expensive at $460.00 is the ThunderBolt personal
lightning detector - about the same size as the StrikeAlert
but its range is extended to 75 miles or 100 km. It has
lots of extra features - LCD messages and sophisticated
calculations of ETA, approach speed etc, and runs off a
9v battery or AC adaptor. The obvious comparison is with
the StrikeAlert, which looks to be much better value, if
not quite as informative.
The above three lightning detectors are small, with a
personal alarm, and in general wouldn't be appropriate for
general warnings at outdoor gatherings. At the next level
is the SkyScan EWS-PRO Lightning Detection System, which
is specifically designed for outdoor use. The SkyScan
EWS-PRO (there seems to be a rule for naming lightning
detectors that says you must slip in an upper case letter
halfway through the name) has a 12v rechargeable power
source with a 7 day life, filtering and discrimination in
favour of only cloud to ground strikes, and a 95db alarm
which can be preset to any range within its 40mile (65km)
detection area. The siren is backed up by LED visual alerts.
All of these can be obtained from Ambient Weather, who have a
good range of most electronic weather instruments. The
cheaper detectors often turn up on eBay at good
prices.
For more on pricing, check out the note at the bottom of the page.
There is undoubtedly a good range of lightning detectors on the
market, and overall the technology behind them is not
particularly complex. I am sure you will find what you need
amongst the models reviewed above - it's only a matter of
sorting out your requirements and suiting them to the price
you are prepared to pay.
But if you need to know where the storm is, whether it's really
heading your way, it's size and how fast it's moving you will need
something more sophisticated, and you can find out what's available
on the Lightning Trackers page.
*Product links and pricing. The products I mention are,
in my opinion, the best of the range in each category.
But this doesn't mean they are just what you are looking
for, and it is always worth following the link to the
manufacturer's page.
But don't buy from there - in almost all cases much
better prices are available from both shopfront and internet
based retailers. At all times eBay and Amazon are worth
checking out, and you will notice many of the links go to
Amazon. Amazon has built a very sound reputation for customer
service, given the huge amount of business that passes through
their website, and many products are accompanied by clear
descriptions, alternatives, and reviews from customers. These
can be very helpful, and I shop at Amazon myself.
But prices can change very quickly there, so if you have made
up your mind on a product and you see a good price there, grab
it before it goes.
Where possible, I provide links to other retailers where their
prices are competitive. Some may be better than they seem if
the prices include delivery and, where needed, batteries -
check the terms they offer.
Finally, I stand to make small commissions on some of the products
I recommend. A lot of work goes into building and maintaining a
site like this, and I am not ashamed if I recoup some of the costs,
and even make a little money on top.
That being said, I will and do recommend sellers where I will not
make anything for myself. One of these is
Ambient Weather
, a useful retail site with good supporting information. But if
you visit there, don't forget to come back!