It will be interesting to see if your ideas come to fruition. There is
nothing on the models to suggest this, but models can change
spectacularly in the course of 4 days and to be perfectly honest, I
wouldn't expect them to stay the same as what is being shown at T+300+
either (I don't think we will see any great cold at 6 days though).

I note that you haven't actually said how they will change and what
new synoptic set-up will produce the cold, or how cold it is likely to
get, or at what actual time, apart from sometime in a 10-day period,
we'll see this change. I guess you are keeping your options open on
those. *))

Hi,
Well from the things that I am seeing at the moment, it looks like
high pressure will slowly migrate further E from the E of the UK, with
low pressure starting to the WSW of the UK, then sinking S across
Central and Southern France as another High builds over from the
Greenland area.
This will pull in a due northerly flow, which will bring some
progressively colder air in.

Obviously cold advection over warmer seas will temper the initial
temperature differential, with the usual shallow convective elements
(Up to 500hPa deep) for a short time, before ridging from the NNW will
eradicate all but the smallest of showers from in the NW of the UK.
With the high building over to the N, it will then slowly veer the
wind to the NE for a while. Then the NE and E of the UK will see the
effects.

With the high remaining to the NE, merging with the one further across
the Ukraine, we shall see the (by then) cold continental air move in
from the E, killing off the showers, and maintaining cold temperatures
into W Europe.

At least, this is the scenario that I can see happening over the
coming weeks, however, as with all these sorts of things, it all
depends on the timing.

Our normal Jet stream pattern obviously will go S gradually as a
result, so S Europe should see some poor weather for a time.

Upper atmospheric temperatures are indeed falling away again, but the
pattern seems slightly altered from last year...hence the timing
difficulties.

The flip flopping of the model scenarios is just one symptom of the
upper atmospheric conditions at the moment...they will settle down to
a solution soon enough.

The continental surfaces are cooling close to the UK, hence the cool/
damp conditions along the E of the UK over recent days at very low
levels...signs of the annual winter coldness gradually seeping
in....look at the model forecast skew/TPhi ascents for the E of the
UK over the next 24 hours showing the dropping 950mb temperature. From
PS 10C to PS 03 C in 12 hours from midnight. I have been tracking this
for a day or two.

This low level cooling will of course keep going over the weeks to
come under continental high pressure...so when we do see E winds, they
are going to be colder than now.

Neo