Model output discussion - Winter has arrived

[Griff]

12z might look bonkers in deep fi if it continues amplification towards Greenland... JFF

[Man With Beard]

2 minutes ago, IDO said:

Mybe with a bit of time, but in the next 7-10 days I am not seeing cold or snow. The upper temps on the UKMO run:

d5>> d6>>

Sure nowhere near a given. We'd need to the low pushed through, cut off to the west and a northerly on the back of it. It's a bit of an ask, but I do think if above average heights persist to the NE we'll get lucky in the end. From a cold perspective, I'm enjoying where this December is going more than any in a long time.

[Fourty Point Three Degrees]

23 minutes ago, swfc said:

Not a great looking gfs 12z early doors. Looks to be on the change to a stormy spell of weather. Block still to the east tho

I cant really see any Atlantic breaking though, there is just no energy in it to ramp it up, and the russian high that its up against is too strong, its probably just going to get colder and colder.
 

[andy989]

7 minutes ago, chionomaniac said:

The fact that I am posting may answer your question....

Goosebumps reading that

[Griff]

12 minutes ago, Griff said:

12z might look bonkers in deep fi if it continues amplification towards Greenland... JFF

Scrap that, every time I speculate the purple monster returns home to roost...

Edited December 5, 2020 by Griff

[dragan]

seems the trend to put the UK in a cool wettish period is set in stone up until day 10ish, after that who knows..... likely a return to somewhat milder conditions is on the cards, although not that much milder, temps ending up around average 

[Captain Shortwave]

I guess the question is whether we can drive some of that warm air from the ridge to our east into a position that might bring more wintry conditions to the U.K. It does look possible that we could develop something towards the Iceland region that could essentially develop a gap for a trough to descend into Scandinavia eventually, if the Russian ridge is still highly influential by this time of course.

GEM looks good for getting the ball rolling.

   
 

From here cold from either the north or east is possible depending on how developments to our east unfold.

Edited December 5, 2020 by Captain Shortwave

[Scott Ingham]

14 minutes ago, chionomaniac said:

The fact that I am posting may answer your question....

Whats your opinion in regards to the strat? I have an outside opinion we could see a split last week into first week of January 

[nick sussex]

Tonights models so far in terms of cold potential .

GFS - Poor 

UKMO -  Okay at day 6 and trending good if it then went onto  follow the  GEM trend .

GEM - Good , eventually ,  but generally useless in terms of reliability .

ICON -Poor early trending okay  later , regardless it’s a very unreliable model which only gets wheeled out in here when it shows the coldest outcome .

NAVGEM- Not out yet but does anyone really care !

 

[That ECM]

1 minute ago, nick sussex said:

Tonights models so far in terms of cold potential .

GFS - Poor 

UKMO -  Okay at day 6 and trending good if it then went onto  follow the  GEM trend .

GEM - Good , eventually ,  but generally useless in terms of reliability .

ICON -Poor early trending okay  later , regardless it’s a very unreliable model which only gets wheeled out in here when it shows the coldest outcome .

NAVGEM- Not out yet but does anyone really care !

 

NAVGEM’S Mum does

[winterof79]

The PV is being consigned to the Siberian side with pincer forcing from the pacific and Russian ends.

Edited December 5, 2020 by winterof79

[phil nw.]

A difference at day 5 with GFS more progressive with the low to the north so the more west -east orientation of the trough results in westerlies coming through.

I am keeping a keen eye on the tendency for that ridging extending west across Norway across towards Iceland as in the UKMO.We keep seeing this on various runs.This helps to drive the trough on a better track se into Europe.

A bit of a standoff and when looking at the earlier ens.could go on for much of next week.A weak Atlantic v Russian block.In this setup after day 4 agreement ends on the way forward with these 2 runs.

 

 

[Daniel*]

8 hours ago, sunnijim said:

You are not wrong, amazed and heartened to see significant snowfall at low levels in the Battle area of East Sussex yesterday ( still melting slowly at 2pm)

Higher ground on the Sussex coast near Hastings had  snowfall too.

Hastings had laying snow on beach. Rare at best of times. Time people stop with the outdated rhetoric you need -5°C uppers minimum you also need to bear in mind with the surprise snowfall in SE yesterday, there was no continental aspect, it was polar maritime air.... uppers were only -3°C, winds were extremely slack and heavier PPN really lowered freezing level significantly.

 

Edited December 5, 2020 by Daniel*

[Polar Maritime]

Thought I was reading the shipping forecast then Nick.

The Models certainly suggesting a more stubborn Russian High over the past few runs, Lots of uncertainty atm which makes for interesting viewing over the next few days.  

[Mucka]

GFS actually picked out the potential slider before the Euros but has moved away from it the last few runs after the Euros moved toward a GFS type solution.

That suggests the GFS may be leading the way on current trends tot he mid term though no doubt being over progressive thereafter.

I have seen this so often where one model goes against the others, the others come on board only for the model that originally went with it to move away.

A blended solution from 144 onward would be currently be best guess but we are really just throwing darts blindfolded at the moment.

Duck!

[Alexis]

6 minutes ago, Daniel* said:

Hastings had laying snow on beach. Rare at best of times. Time people stop with the outdated rhetoric you need -5°C uppers minimum you also need to bear in mind with the surprise snowfall in SE yesterday, there was no continental aspect, it was polar maritime air.... uppers were only -3°C, winds were extremely slack and heavier PPN really lowered freezing level significantly.

 

True, but you can't blame people for questioning 850temps when they've had a lifetime of rain events at -5 and -6C!

[Catacol]

8 minutes ago, Scott Ingham said:

Whats your opinion in regards to the strat? I have an outside opinion we could see a split last week into first week of January 

Later. Go mid to late Jan I think.

But I have to chuckle when reading some of the posts in here. The SCEuro High that is becoming a long lasting neighbour might not be helping us now in an obvious way - but look at the global pattern! Even if you aren't able yet to fully grasp teleconnections and how they work, look at the amount of amplified ridging on this chart....

or if you prefer the meteociel style - the charts for today. Nothing especially flat, a generally disorganised vortex, some big troughs diving to relatively low latitudes - what's not to like?

Fancy a bit of 1999? 

Or 2000?

Or frankly a whole host of other years in the last 25. The current pattern I think is in the top 20% of "interesting" 5th December setups since the world started to warm dramatically....

 

[bluearmy]

Gefs at day 8 has the trough dug a little less into Europe which is less good for coldies ..... more west to east than nw to se 

[Geordiesnow]

7 minutes ago, Daniel* said:

Hastings had laying snow on beach. Rare at best of times. Time people stop with the outdated rhetoric you need -5°C uppers minimum you also need to bear in mind with the surprise snowfall in SE yesterday, there was no continental aspect, it was polar maritime air.... uppers were only -3°C, winds were extremely slack and heavier PPN really lowered freezing level significantly.

 

All transient snowfall which did not even stick around for long. Yes admittedly, more areas did see more snow than I thought but it was always going to be transient in nature. 

Reality is now, low pressure in charge, no real significant cold on the way and no real signs of the PV dropping into Scandi so any chilly air will be scraps only. Quite poor for December really. 

[MattStoke]

44 minutes ago, chionomaniac said:

The fact that I am posting may answer your question....

Indian Summer? 
 

I might get lynched for this  

[Scott Ingham]

1 minute ago, Catacol said:

Later. Go mid to late Jan I think.

But I have to chuckle when reading some of the posts in here. The SCEuro High that is becoming a long lasting neighbour might not be helping us now in an obvious way - but look at the global pattern! Even if you aren't able yet to fully grasp teleconnections and how they work, look at the amount of amplified ridging on this chart....

or if you prefer the meteociel style - the charts for today. Nothing especially flat, a generally disorganised vortex, some big troughs diving to relatively low latitudes - what's not to like?

Fancy a bit of 1999? 

Or 2000?

Or frankly a whole host of other years in the last 25. The current pattern I think is in the top 20% of "interesting" 5th December setups since the world started to warm dramatically....

 

I for one have been banging on about this pattern sustaining for the very same reasons. Im very surprised at the nino esque nature of the atmosphere at the minute. Every winter one parameter not foreseen is usually set up to spoil background signals that look positive for Western European cold but this year I think this unforseen level of pacific forcing might actually work in our favour. I do half agree that mid-late January is probably the landing date but part of me feels were still underestimating convection in the tropics. What I do agree with though from yourself and chionomaniac is that there will be even more distress put on the strat come January. So I guess your seeing first time unlucky second time down she comes from up above?

[Methuselah]

The Beast is dead. Long live The Beast! 

    

Well if (Heaven forbid!) that GFS run is anywhere near correct, the upcoming 'front-loaded winter' might be only ten-days' long!

[Allseasons-Si]

7 minutes ago, bluearmy said:

Gefs at day 8 has the trough dug a little less into Europe which is less good for coldies ..... more west to east than nw to se 

Incidentally the Scuasian block is a tad stronger though Blue

12z 234 v's 06z 240.

[Radiating Dendrite]

10 minutes ago, Geordiesnow said:

All transient snowfall which did not even stick around for long. Yes admittedly, more areas did see more snow than I thought but it was always going to be transient in nature. 

Reality is now, low pressure in charge, no real significant cold on the way and no real signs of the PV dropping into Scandi so any chilly air will be scraps only. Quite poor for December really. 

At least it is seasonal though - better than a December CET of +9c.

[Catacol]

1 minute ago, Scott Ingham said:

 So I guess your seeing first time unlucky second time down she comes from up above?

Along those lines. Need to see just how much stretch the wave 1 displacement attack mid month will create, and just how sizeable an MJO forcing we can get after that hopefully enhanced with another +EAMT and substantive wave breaking. That would be the second hit - but I reckon it will take a third via the next round of momentum uptick in mid/late January.