"Dave Cornwell" wrote in message
...
Bernard Burton wrote:
"Dave Cornwell" wrote in message
...
I notice on the 10 am radar on both IR and vis a very well defined but
completely isolated clump of thick cloud over the Midlands. I wondered
at first if there had been a fire. Not associated with any rain.
Dave

The patch of cloud to which you refer, Dave, is at about 6000ft-7000ft,
and can be traced back to yesterday's convective activity just east the
Welsh border. The convection was capped at that level, and produced a
saturated area which would probably have been maintained by an absence of
dynamic descent in that layer plus internal convective overturning as a
result of cloud top cooling.
A 3 hourly sequence of imagery can be found at:

http://www.woksat.info/etctg02m/indextg02m.html
----------------------
Thanks Bernard, for the explaination. It now seems to be diffusing
outwards and has in fact caused high level cloud here. A very interesting
image still, as the central area is still surrounded by its own clear
border.

Very strange looking.
Reminds me of those pictures you see of penicillin where there is
a clear area between the penicillin mould and the bacteria.
--
Col

Bolton, Lancashire
160m asl