"Mike Rapoport" wrote in message
ink.net...

"Icebound" wrote in message
...


Thanks! I have been using "CB" and "thunderstrom" interchangably, perhaps
this is not strictly true.


Ron has correctly described the difference. CB is a cloud, thunderstorm is
a condition reported only when thunder is heard or lightning seen. Being
the "thunderstorm cloud", the terms CB and thunderstorm are often used
interchangeably in generic descriptions, but we can and should be more
precise.


I agree that most observers would call a hailing cloud a CB but the hail
that fell on me yesterday was pea sized and mostly clear yet fell from a
cloud that had a top of perhaps 15,000' and was not producing thunder.


Where, geographically? And did it fall on you on the ground, or did you
encounter it in flight? And how was the cloud top determined.



North Idaho. I was on the ground (bicycling in hail of all things) The
tops I estimate at 10-12k based on my experience flying in the area (I am
confident that I could easily top them VFR). I gave 15,000' as a very
conservative estimate, I have a high degree of confidence that they were
lower. The highest terrain around is 6200' and this was sticking to the
bottom of the cloud so the vertical height was about 6000'.


I don't pretend to be an expert in mountain meteorology. But because the
direction of the wind plays such an overwhelming part in the lift equation,
it would be my guess that a TCU was developing, the vertical currents were
there, the coalescence of water was occurring and freezing. But in a
typical flatland TCU/CB this build-up keeps going for perhaps up to couple
of hours and great height, here I would guess that a wind change killed the
vertical currents rather quickly... and the precipitation, no longer
supported, simply fell out.

My guess, don't know.