Boltek Lightning/2000 - Manual (Page 79)

R E A L - T I M E L I G H T N I N G D E T E C T I O N
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Default yellow alert trigger level: 25
Default red alert trigger level: 50
Record kept: No
The stroke rate change counter shows the percentage
change in the stroke rate between one minute ago
and now.
For example, if the stroke rate one minute ago was
100 and the stroke rate now is 120, then the counter
would read “+20%”; if the stroke rate one minute ago
was 120, and the stroke rate now is 100, then the
counter would read “-17%”.
If the stroke rate one minute ago was zero, and the
current stroke rate is zero, "--" is displayed. If the
stroke rate one minute ago was zero, and the current
stroke rate is non-zero, "*" is displayed.
Sudden changes in the stroke rate for a storm could
be signs that the storm is exhibiting potentially
dangerous behavior. A rapid increase in stroke rate
followed immediately by a rapid decrease, or vice
versa
has been linked to certain severe
characteristics, such as hail, microbursts, and even
tornadoes.
When you specify a trigger level for the red or yellow
alert, you are specifying the percentage change that
must occur if the stroke rate is 100 strokes per
minute. The percentage change that is needed for
alert status at higher stroke rates is somewhat lower,
and the percentage change that is needed for alert
status at lower stroke rates is higher.
At 1000 strokes per minute, the percentage change
required for an alert is one-half the value specified as
the trigger level. At 10 strokes per minute, the