"Martin Rowley" wrote in message
...
On 15/11/2012 09:29, Martin Rowley wrote:

... using this site:-

http://www.sat24.com/

choose VIS imagery for Europe and you can see (now the sun is
illuminating the cloud tops) a near-perfect arc of line convection with
(I think) just one break. Seems to be coming forward associated with
cyclonically-sheared development associated with the
slow-moving/warming-out vortex seen here ...

http://www.wetterzentrale.de/pics/Rtavn001.png


... just correcting myself somewhat; undoubtedly a convective element, but
cross-referring to IR image, obviously NOT a classic line-convection
event - the cloud tops aren't nearly cold enough and the 'line' doesn't
show up to match the VIS picture. So more like a boundary-layer feature -
perhaps propagating outward from the deeper convection further west ...??

Martin.


--
West Moors / East Dorset
Lat: 50deg 49.25'N, Long: 01deg 53.05'W
Height (amsl): 17 m (56 feet)
COL category: C1 overall

Re my (and your) earlier posts Martin, I was referring to the line of IR
activity. I agree that the narrow line of convection on the vis image is a
boundary layer feature, and is probably tied to a change from southerly to
westerly flow across it. The boundary layer air ahead of the line has been
over the cooler water off the NW African coast, and could act as a trigger
to lift the slightly warmer air circulating the vortex at lower levels,
initiating the line of convection.

--
Bernard Burton

Wokingham Berkshire.

Weather data and satellite images at:
http://www.woksat.info/wwp.html