The low towards the end of next week is still causing the models some headaches in how it clears

Again as in the 06z chart - you can see signs of a stratospheric warming on the Siberian side of the Arctic on the 12z run at 10hpa not an SSW but this could be a possible outcome:

After a mild zonal start to December - there maybe blocking over Xmas into the New Year? Watch this space.

Quick heads up... I'm making ECM ENS / ECM op standard distribution chats available on TWO very soon. Here's one from tonight's 12z suite.

Good work Brian. Any chance you could start moving those 850's towards -10c as we progress into December ? 

 I'll happily try.

On today’s 12z runs I seem to like the ECMWF much more, it clearly look much better than the FATHOMED GFS.😆.

Much better if we all get soaked in heavy rains and proper Autumn Atlantic Low Pressure give some stormy winds, or at least severe gales.

Cold Pooling in East and NE Europe gives way to less cold West SW winds, UK Cyclonic flow at times.  Mild at times but also some cool chilly and wet weather as well coupled with heavy blustery showers and squalls.

Cold air over Arctic and Russia and also over Canada NE and East including NE USA, Low Pressure as well as blocking High pressure over Greenland and parts of NE and E Canada plus Arctic and Siberia NW Russia at some points of the ECMWF 12z is very interesting to see indeed- The Arctic High and Canadian NW Russia Blocking High NE Norwegian Sea blocking High should be helping drag colder air southwards from Arctic and build it across the Mid Lattitudes in time for 2nd week of December.

And not to forget, Greenland getting very cold as well.

NE Atlantic and N Europe Blocking could re assert by 2nd week of December- I am getting teased by looking at that cold arctic pooling at 192-240 hours- spreads across NE Norwegian Sea and NE Europe NW Russia with a big Arctic and Siberian High merger!!.

So we shall get excited as we get past next 7 days innit😀.

After the next 9 days things shall get interesting.

We need GFS, UKMO and ECMWF get the agreed guesses match closer together as we get to 8-10th December.

😀.

Can’t say the 0z ensembles paint a wintry picture though (yet)

http://old.wetterzentrale.de/pics/MT8_London_ens.png

ECM ENS / Op standard deviation charts are now available for a range of locations. All can be selected from here:

https://www.theweatheroutlook.com/twodata/ecmwfens.aspx 

Direct links to a few:

London
https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=na&lg=850&lglocation=london

Liverpool
https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=na&lg=850&lglocation=liverpool

Aberdeen
https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=na&lg=850&lglocation=aberdeen

London 00z plot below

Waiting game this morning for Coldies about 2 weeks before we see anything interesting here. But HLB is still prevalent and the vortex is still a shambles so more hope than usual. We just need some luck

blocking is becoming a theme in the later stages of GFS last few runs and cold frosty weather perfect for the time of year. Then the infamous faux cold possible although to me that phrase is silly - if it’s cold at the ground level who cares about the 850s

Martin

Its a risible phrase, indicative of confusion.

The next feature to flag is the Arctic High building south as per the last few EC runs. GFS not so keen but this scenario has historically been the precursor to the coldest Easterly outbreaks. 

In the meantime a week of the typical British Autumn - which has been notably missing this year.

Cold is cold, whether 'faux' or not. 

The GFS Para shows what happens if we get lucky stunning Scandi High at 384h. Lots of luck to get there though.

The Signal and trigger is there in the Western NW Atlantic, Florida East NE USA and Greenland as well as the NE Atlantic and NW Europe as well, as is being shown first on today’s GFS 00z run.

The Arctic High is supported by both the GFS and ECMWF Models as we go to 216-240 hours et all...

8-10th December could see the Blocking in the Eastern NE Atlantic Ocean on the NW Europe side.

We see some active Low Pressure during the next 5 days, then by day 8-12 this Jetstream over West and NW Atlantic producing Low Pressure systems will move out from the UK NW Europe as we get some Azores High ridging set up over the UK NW West Europe.

Cold Eastern Europe NE Europe weather with blocking high affecting then this week and in the following weekend to early in 2nd week from now.  Though it does turn less cold in NW Europe and N Europe NW side during days 4-12.

The Blocking signal has a chance but it needs another 6-8 days waiting from today to show up in the day 6-9 range.

A East Greenland and Icelandic High is going to need to be created for this cold retrogression of Azores High to happen.

😆😀

Next Wednesday is looking like a potentially interesting day, according to the 12z GFS:-

Other than that a pretty meh kind of run really, pretty stock winter fare - Scotland doing better for colder weather but nothing too cold on offer really. Be interesting to look at the ens when they're out and see if any manage to build HP in a more favourable position than the Op.

I think four of them show substantial northern blocking. There are quite a few mehs thrown in as well as a number of mild runs. Probably the pick for coldies:

Certainly a number of runs turning colder in the latter stages on the GEFS 12z!

A bit of a lull on Friday as we end Autumn not completely dry but less windy

Then winter begins with another big area of low pressure from the Atlantic

Looks like we have a go at a SSW from the Siberian side twice - and we all know that from that side of the Arctic was where the true cold beast from the east originated from that sort of SSW

1st Attempt 

2nd Attempt:

 As far as I can go at +384z just for fun but if you were to run on beyond - those warmer temps in the stratosphere over Siberia will infiltrate into the Arctic Polar regions!  -One to watch?

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Even if it's just a SW instead of a SSW - Then surely a jump from -80c @10hpa to -40c @ 10hpa (a leap of some 40c in a day or two is enough to disrupt the PV and have an impact on the troposphere and our weather systems!? 

One reason to care about the 850s is that clouds producing precipitation are likely to be at or above that height, which for the "standard atmosphere" with a surface pressure of 1013 corresponds to about 4,500 ft (if the surface pressure is lower than that then the 850 level will also be lower). So if the 850s are above zero you are unlikely to get snow at the surface. Of course if it's "cold frosty weather" that you want, then that doesn't enter into it, but I suspect that for most of us it's snow that we want above all.