Yes, it's certainly causing heavy and prolonged rainfall in S.Essex so my
fears of it petering out yesterday were unfounded! In fact this looks like
being the heaviest daily rainfall for a year or more in these parts. Can't
wait for it to stop to measure it!
Dave
"Waghorn" wrote in message
...

wrote in message
oups.com...
Notice that according to the radar the cold front is now around the
east coast - and is still forecast to move well into the continent
during the day - so what's causing this persistent "blob" of rainfall
in the south? It would suggest a very marked distortion of the front,
but there's nothing in the charts (e.g. the T+12 of the Met Office) to
explain it?

Nick


As per many model predictions a weak surface low is trying to form over NW
France.Have a look at the water vapour imagery-
http://www.sat.dundee.ac.uk/pdus/BW/...90600BW1_g.jpg

This is due to strong upper air forcing (dark areas ín WV).A plume of warm
moist air is being drawn from the south (a notional warm conveyor belt)
and
is undergoing ascent over southern England /Channel (notional 'cloud
head').Convective instability is being released to create embedded
thunderstorms,perhaps by forcing over the topography eg the
Downs.Hopefully
we'll get a Larkhill ascent this morning so we'll be able to see the
vertical structure of the plume.
Current UKMO runs keeps this as a wave feature on the CF and a fully
developed surface low.a recipe for slow clearance and protracted rainfall.

BTW ex TS Irene looks good in the WV image,


--
regards,
David

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