"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
...
Unusual line of very sharp showers shows up on the 1300
radar stretching across south Oxon, Bucks and Herts.

I've seen this before, though rarely, when vigorous
cumulus penetrates the overhanging altostratus shield
of an ana-coldfront.

Martin ... mechanism please !!

Philip Eden

Don't like to steal Martin's 'thunder' :-) but I was wondering whether it
was a split cold front with the showers mentioned developing on the surface
cold front and the main band on the forward upper front. Will be interesting
to see what's on the 12Z analysis.

Jon.