[TowerTalk] Re: Lightning & corona discharge

[Robert Shohet]

Hi Jim,

> There are reports from trained observers...amateurs with multi-tower
> installations...who have observed storms with frequent cloud to ground
> lightning, where that lightning ceased when near the antenna field, and
> resumed after passing it.  So, I am inclined to believe that a well
grounded
> tower system, with or without pointy things, will tend to reduce the
> resistance in the cloud to ground circuit.

I am going to cast doubt on that conclusion.  I do not doubt that people
actually saw what they saw, but I SERIOUSLY doubt that the storms
behaved differently BECAUSE the antenna system was well-grounded.

Thunderstorm behavior is often unpredictable because of invisible phenomena
occurring on a MINUTE scale over areas as small as a few hundred yards!

The presence or absence of trees, hills, and small differences in air temp,
air moisture,
low level gravity waves, winds and other factors, ALL INVISIBLE, can make an
incredible difference on a VERY localized weather event.

The movement of storms is not uniform either, as "tracks" set up and
disappear
without notice or warning and often contribute to the exacerbation or
mitigation
of small-scale weather phenomena.

On my hill, which is maybe a 1/2 mile wide AT THE MOST, some days the storms
"part" and then reform on the other side, sometimes they don't climb the
hill (just
 300' vertical feet) and blast a spot 3/4 mile South, sometimes they stay on
the West side of the hill
and blast a spot 1/2 mile North of me, etc.  I can always see these storm
clouds, and the
cloud swirls and rotation of the winds.  Often the winds blow in one
direction at
ground level and a completely DIFFERENT and sometimes OPPOSITE direction
less than 1000' up!

ALL these factors and many others contribute, especially very small-scale
geography.
This all plays an enormous factor in what I observe and what others can and
have
observed.

Meteorologists have recently been able to observe the effects of multiple
vortices within
tornadoes and hurricanes that explain why one house can be destroyed and
another house
100' away can be almost untouched in the middle of a monster storm.

Microbursts are another VERY small-scale phenomena with often catastrophic
results,
as are straight-line winds.  ALL of these phenomena and others can be
present in a
T-storm - even a very small one, and what someone sees and experiences in
the WRONG
place can be amazingly different that what is seen and experienced 1/2 mile
away.

I have no doubt that these phenomena, of which we are still largely
ignorant, explains
a lot of what others have experienced and seen.

I remember living in Ithaca, NY for 4 years while attending Cornell (and
studying WX
among other things) and repeatedly witnessing the snow squall clouds break
up over certain
spots and reform less than 1/2 mile away with incredible difference in
snowfall!
What SPECIFIC direction the wind was coming from was a large determinant in
whether
or not the clouds broke up and where they would reform.  Altitude and local
geography
also played a huge role in this phenomena.  Similar things occurred with
Summer T-storms.

Where there is varying geography and where terrain influences low-level wind
and moisture
patterns, you can have dramatic WX phenomena that changes quickly and
unpredictably and
may explain a lot of what is seen.  But a good tower ground CAUSING a
T-storm to break
up and reform on the other side?  NO WAY!

73
Bob KQ2M