On Apr 27, 10:47*pm, Dawlish wrote:
On Apr 26, 12:56*pm, "Jon O'Rourke" wrote:





"Dawlish" wrote in message

...

The Met Office still don't think the rain will be heavy enough for any
kind of advisory/warning tomorrow. The FAX charts still show the

development of that wave depression and I still think there could be

some atmospheric fireworks in some areas and some very heavy rain with
that set-up.

Some heavy rain is likely but the detail has varied a bit from run to run
and hence the risk for any particular area is probably deemed less than the
required 40%http://www.metoffice.gov.uk/weather/...warnings..html
To a certain extent this is reflected in the 1000Z issue Long TAFs which
indicate moderate rain with no mention of heavy as yet for any particular
airfield (30% risk threshold).

GFS currently has the highest 48 hour totals over parts of northern England,
more especially over the Pennineshttp://91.121.93.17/pics/Rmgfs48sum.gif

Visible imagery has some deeper looking tops due west of Biscayhttp://www.metoffice.gov.uk/satpics/latest_VIS.html

Jon.

Finally got a weather warning! I've been convinced for a day that this
wave depression would produce some very heavy rain, but pinpointing it
was beyond me! It has ended up further North than it looked like it
would get, but there has been some excellent convection in
instability, in advance of the front, creating storms for some. Then,
as the wave tracked NE, another area of deep convection has brought
thunderstorms and heavy rain to the North Midlands and Yorkshire. The
present weather radar shows that heavy rain now in in the NE of
England/ SE of Scotland and there's another nice circulation producing
some heavy rain over Wales too. That could drag some storms over the
SW later - perhaps they are just beginning to show in the SW
approaches.

An interesting night to come for some! Many of us, however, may be
left thinking what all the fuss has been about!

Paul- Hide quoted text -

- Show quoted text -

HI all,

Monday - Another fascinating day weatherwise. That little wave has
begun to occlude, but is still being accompanied by some very heavy
rainfall in Fife and Perthshire. It's slow-moving too. There could
well be reports of flooding with that lot.

It shows that the uplift associated with this wave depression and the
location of the heaviest precipitation at a given future point was
extremely hard for the MO to predict. No weather warnings were given
up until late on Sunday afternoon, as far as I'm aware and I can fully
understand why. I was expecting the major area of uplift to be to the
SE of the main trough and there were some significant trough lines and
some thunderstorms, but they were concentrated in bands and many areas
missed out and stayed dry.

For the main trough and its developing wave to drift so far North,
took forecasters by surprise; as did the intensity of the
precipitation that developed around the centre of the developing low.
So: not a great forecast, MO, late on the weather warning, but
entirely understandable. Its possibly down to data grid sizes and the
small area occupied by the "wet" part of that wave. The forecast
models just didn't have enough data to produce accurate forecasts of
precipitation intensity and location.

Dead interesting though - as was that circulation over Wales last
night and the rain which is presently over NW England, behind the main
trough. It looks like an eddy effect, swirling behind the first wave,
or it may be that the wave developed a double centre and the second on
is beginning to decay and is being presently re-absorbed. Any other
views on all this?

Paul