LOL WHAT!

Without doubt that is the most extreme chart I have ever seen. I know its 384, I know its an ensemble pertubation, but someone is taking the mick to through a chart in like that after the December we have had. 

EDIT that cold pool has a central temperature of -27C. Someone needs to save and frame that chart. Jesus.

If only eh??

I know this is totally pointless, but more P18

Coldest uppers on the planet just next door, unbelievable.

People, is this even possible? Has anyone ever seen a chart like this before?

Yeah, in January 1987! (850s were within a gnat's whisker of -20 down here as a similar chunk of deep cold air was propelled westwards. That led to 30ft drifts on the hills here and a week and a bit off school, as well as food delivered by Chinook helicopter. Wouldn't mind seeing that again one day!)

We also had this chucked out 9 days ago:

Increased clustering of uppers between -5 and -10 at 384 on GFS ens?

i had to laugh myself when I saw that one!

There is plenty of time for colder weather this winter, but it looks to my untrained eye that it could be a big waiting game- the dominant Eurobeast HP is the main player this year and we will all have to dance to its tune, like it or not.

ECM seems to want to be the 'Hamlet' model this year which is quite odd (probably an op run statistical quirk) because in the past it has over egged height rises over Scandinavia.

If that's the case (not looked at the details) it looks to be caused by high pressure to the west of the UK. 

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gefs/ps/500hpa_384_ps_slp.png

Horrendous stuff this morning whichever way you look at it - stalled systems from the GFS delivering vast amounts of rain, very mild and wet ECM, plus its 32 dayer mild and wet throughout. 

I would think after this month, we only need to see 'normal' Atlantic pattern for the remaining 2 months to guarantee the mildest winter ever ? And one of the wettest too 

I think I read somewhere else that the PV is as large as has ever been observed, I think it's fair to say heights to the NE will only be transient.

Yes indeed that is a stark change of spread in one day. Recent models have shown a set-up that, without the SW-NE jet being so determined, would have looked very promising in some respects at 00z 25th. I think the 00z GFS is among those- a low trying to track S from near Icelend, HP (though weak) in the Atlantic, etc. Then that Azores low streams up.

 What would it take for that low NOT to make it? For the more northerly low to come into play? I only ask because, with the uncertainty from 26th you've mentioned, I haven't abandoned all hope.

I have no idea and I'm not sure that the/a Porlar Vortex is actually quantifiable is such a way but even if it is it does not follow that heights cannot be maintained to our NE, far from it. In fact in the right location it may encourage high pressure over Scandinavia.

http://www.wetterzentrale.de/pics/Rhavn1801.gif 

So, essentially no it's not really fair to conclude that. Whether the High develops or is transient is not necessarily as a result of the PV any more than its existence in the first place is an indirect consequence of the PV.

I suppose you could quantify it in different ways, though how relevant any of those would be is beyond my understanding. You could measure minimum surface pressure, spatial extent, geographical persistence, etc and no doubt a lot of physical properties that could parameterise various factors, although I couldn't tell you what these were.

But as you say, these may not relate directly to other macro-scale developments.

Although we end up with no 850s below zero on 28th, still a 15 degree difference on boxing day with three distinct clusters: Higher, Lower and middle ground...

That is a 'precision' long fetch south westerly with high and low pressure systems perfectly aligned to produce for the UK exceptional warmth, wind and rain, if only the weather could send northerly or easterly winds at us with such precision!

I really don't see any sign of a pattern change I really don't, I would bet a months wages now that both January and February will be mild although maybe somewhat drier.

As in 1988/89 cold weather will probably arrive in April.

Andy

Can you work out the weighting of the three? Looks like there might be about 8 below the -5 uppers threshold? If so, that's more than a third of members.

The spread for the south comes a day later.

The SLP ensemble show a similar spread pattern with a range of 9mb across all members on Cheistmas morning and 50mb by Boxing Day evening!

i guess it's a little later than your famous winter is over post of winters past Andy 

having spent a while sifting through previous winters I would certainly not rule out cold weather in January or February you only need to look as far back as the winter of 2012/13 ....I wouldn't bet a months wages on it unless your flush with cash 

Sounds a post of desperation I think but you could well be right. I see little light on the horizon to lighten the mood with the ECM 10 day Mean maintaining the patterning at Day 10 and no doubt beyond.

http://www.wetterzentrale.de/pics/Reem2401.gif

My full morning report can be read HERE 

The mean means nothing Martin at that time scale when there is an issue with a short wave

http://www.meteociel.fr/modeles/gefs_cartes.php?code=19&ech=276&mode=0&carte=0

all of them don't know what to do with it take gm for example

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=204&mode=0&carte=1

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=228&mode=0&carte=1

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=240&mode=0&carte=1