ralph@inuxc.UUCP (Ralph Keyser) (11/19/85)
I'm hunting for some information from more experienced and weather
wise pilots. There's a considerable gap between IFR under the hood and
"real" IFR, and most of that gap is filled up by weather. Last week I
was cruising along at 6000' more or less between layers. There was a
group of thunderstorm cells at about 10 o'clock and 40 miles
according to the approach controller. Things looked good ahead of me
and the ride was smooth, when suddenly the clouds just under the nose
of the plane flashed with a stroke of lightning. Now, somehow,
I've always associated lightning with thunderstorms. If there's
lightning, then there is a thunderstorm. Obviously, however,
that's incorrect since I was not in a storm or about to fly
into a storm, but lightning flashes were still present.
So now I'm curious. Must you have a thunderstorm around
somewhere to get lightning? Facts and personal experiences will be
greatly appreciated!
Ralph Keyser
Indianapolis, INdsi@unccvax.UUCP (Dataspan Inc) (11/20/85)
I've observed the same effects around broadcasting towers. At several
sites I've visited, thunderstorms up to 20 miles away (and local wx being
scattered) can induce, er, specatacular arcing and popping both around
guy wire and base insulators. In many of these cases there is no evidence
of a thunderstorm "nearby" except for radar weather and the arcing. We're
not talking about little pops, either, but stuff you can sometimes hear
inside a brick building.
A colleague of mine insists that dusty weather can induce the same
effects in towers; I was just wondering if dusty weather can cause
"lightning" as well (or help propagate it, etc.)
David Anthonykerry@ctvax (12/01/85)
I usually follow this rule of thumb when dealing with lightning: make a 10
degree turn to the right every time a flash is seen, until I have made 18
of them.
Seriously though, lightning is almost always associated with showers and
thunderstorms, and even simple towering cumulus clouds. Although, I have
done some flying in southwest Texas in the dry season where dust devils
can kick up the dust and cause a few static discharges.
A lightning discharge can usually be expected whenever:
1. The temperature is between 5 degrees and -10 degrees Celsius.
2. Mixed rain and snow is encountered.
3. Severe precip. static occurs on the radio.
4. A corona forms on the propeller or other parts of the airplane.
kerry. ct @ CSNet-Relay