Model Output Discussion 4th Dec.2013-12z onwards.

[MPG]

So..all this talk of mild is true regarding 850 temps, but surface temps will much below average? So why are people talking of mild, im tall but my head will definately not be at a level of 850's to feel that mild air! As I said this is all based on 850 temps and not surface temps.

[fergieweather]

 

So..all this talk of mild is true regarding 850 temps, but surface temps will much below average? So why are people talking of mild, im tall but my head will definately not be at a level of 850's to feel that mild air! As I said this is all based on 850 temps and not surface temps.

Correct - degree of mixing is critical and gradients hardly look especially sporting. Some areas will indeed be milder in strict sense (e.g. western / NW coastal districts) but conversely chilly to SE, albeit amount of insolation day-to-day hard to gauge given tricky boundary layer f'cast issues (not least prevalence and longevity of any fog, plus nuance changes in the flow direction such as more backed at times).

[forecaster]

 Correct - degree of mixing is critical and gradients hardly look especially sporting. Some areas will indeed be milder in strict sense (e.g. western / NW coastal districts) but conversely chilly to SE, albeit amount of insolation day-to-day hard to gauge given tricky boundary layer f'cast issues (not least prevalence and longevity of any fog, plus nuance changes in the flow direction such as more backed at times).

 

I think the gradient might be enough across the SE by the end of the weekend to have accomplished significant mixing there. Td at EGLL currently +2C, but would expect that to be more like +7C (ish) by Monday. Light drift from the S would be very slow to mix in drier air again next week. So I would expect persistent fog to be more an issue than frost and freezing fog, in the SE anyway. Could be very boring in the SW with an Sc layer instead. I think the chances of a decent wintry continental high were dealt a blow a few days ago when models started showing this weekend introducing a westerly flow rather than dying northerly or post-northerly ridge. The higher dewpoints I think make a more foggy autumnal, but not notably cold, spell more likely.But....I'm quite accustomed to getting it wrong. 

[johnholmes]

I think it is a fine balance between the Atlantic air getting all the way into the SE 1/3 of the country. Well the bottom 1000-2000ft. 50/50 I would say, and by day 6 looking like a feed off Europe with the 500mb heights looking to be at their highest around 50-51N thus a feed from Europe rather than the Atlantic by then. Although just where the surface high will be centred could be 2-3 degrees north or south of there. The emphasis at height does suggest that the main area of +ve heights will be north of 50N.

[phil nw.]

Yes it seems that forecasting surface temperatures looks a little tricky John.As you suggest it's all very much reliant on how the surface high orientates and positions itself.

 

Looking at the 06z GFS run as an example,although from this range not reliable but an idea what a subtle change in the 10m wind direction can do where we have a Euro high in a slightly different area within a couple of days.

T120hrs

 

and now T168hrs.

 

The first image set, as we can see, shows the colder surface temps with a risk of frosts in the central and se quadrant of the UK with a drift of the colder continent.The second  set indicate the milder influence of a sw influence as the high moves around.

 

Subtle differences at the surface in a stable 500hPa blocking European pattern with the UK on the periphery under +ve 5C uppers throughout next week.

 

 

[Potent Gust]

 Correct - degree of mixing is critical and gradients hardly look especially sporting. Some areas will indeed be milder in strict sense (e.g. western / NW coastal districts) but conversely chilly to SE, albeit amount of insolation day-to-day hard to gauge given tricky boundary layer f'cast issues (not least prevalence and longevity of any fog, plus nuance changes in the flow direction such as more backed at times).

Hi Ian 

 

Thanks for your input as ever. Where does the Midlands stand in the current output? Everyone is talking about a NW/SE divide but where do we fit in? I live just outside of Birmingham.

[gottolovethisweather]

It's must be very much a minority option though, everything would indicate a slow return to zonality from this synoptic position.

 

One man's positive is another man's negative and vice versa. I do feel this darn HP cell won't be going anywhere fast and I just hope it does move off somewhere welcome once a change occurs in tandem over the Pacific for example. Those golden era years that you so favour are but a distant memory and I personally hope they stay there, but I guess anything's possible. The main question now has to be how much sunshine (lovely IMBY today) we will all see and how many Frosts will see as consequence. All a lot of unanswered questions but nothing zonal as far as I can see, in say the next seven to ten days as per UKMO and Ian F etc.

Edited December 6, 2013 by gottolovethisweather

[Ali1977]

Hi Ian  Thanks for your input as ever. Where does the Midlands stand in the current output? Everyone is talking about a NW/SE divide but where do we fit in? I live just outside of Birmingham.

In the middle ....either or...

[gottolovethisweather]

Hate to admit it, but Height rises to our east, doesn't shift anytime soon.  See you guys in two weeks.  Bah, only joking lol, but as BFTP said, its all SWerlie from next week. Could be that 's the case right up to xmas. Obviously, not going to right xmas off at this range but for the next week to two, the writing looks to be on the wall. 

 

On the bright side, the UK should be relatively dry for the next week or two.

 

Thereby mitigating the warming effect of the SW'rly flow too I reckon. Yes the nearer to the SW approaches you're located I guess it will feel rather spring-like on the odd day, if that floats anyone's boat then fair play. Coming back in two weeks might be a good option IBTHTS, back to lurking in the snow and ice thread for now.  There will be light at the end of the tunnel, it just depends which direction it eventually comes from.

Edited December 6, 2013 by gottolovethisweather

[Cheshire Freeze]

One man's positive is another man's negative. I do feel this darn HP cell won't be going anywhere fast and I just hope it does move once something changes over the Pacific for example. Those golden era years that you so favour are but a distant memory and I hope they stay there, but I guess anything's possible. The main question now has to be how much sunshine (lovely IMBY today) we will all see and how many Frosts will see as consequence. All a lot of unanswered questions but nothing zonal as far as I can see, in say the next seven to ten days as per UKMO and Ian F etc.

 

It's like groundhog day on here.....not just in terms of the weather either.

 

Every time I view this thread there's a one line post from one person talking about how it's going to be zonal- like a stuck record. It hasn't been zonal for weeks (I guess it's another innocuous word threatening to be banished by the swear filter at this rate). Nothing more to say at present other than there looks to be nothing particularly inspiring on the horizon just yet. We get thrown a bit of interest (increased amplification) then it's subsequently dropped once more. High pressure around Europe starting to slightly concern me going forward but plenty of time for things to change.

 

P.S give it 5 years and at this rate all posts will consist of is caravans and even larger teapots!

Edited December 6, 2013 by CreweCold

[gottolovethisweather]

It's like groundhog day on here.....not just in terms of the weather either.

 

 

 

Yes, we must just continue talking amongst ourselves   as the UKs weather is currently ignoring our desires. I suppose it will soon decide which way it wants to go for the rest of December. 

 

Just where is the zonal precipitation signal going to emerge from and where does the likelihood of it happening lie within the ensmbles, in deep deep Fi that's where. Maybe the 17th December onwards might develop something a bit more than drizzle, clutching at many straws though. So to reiterate as CC rightly suggests HP domination is here to stay for the reliable, nothing to see here, please move on.

 

 

Edited December 6, 2013 by gottolovethisweather

[Cecil Hogmanay Melchett]

You know it really is a bit mundane the outlook but the thing that actually annoys me is when the model output gets tedious.

Some folk look forward to Eastenders or Emmerdale,i look forward to 3.30pm and the next instalment of wetterzentrale,at  times like this i cant even get my fix of 'will it,won't it'.

Its almost like watching repeats of a film,you already know the outcome.

On a more serious note we just have to accept we are primed for a pretty boring week to 10 days(maybe longer)of anticyclonic gloom.

IMO the next cold outbreak will be from the North,im looking for some kind of retrogression of the euro high into the Atlantic,i honestly feel an hope of an easterly is dead,the best route is the PV moving to our NE andsome kinf of vaccum in the Atlantic.

It might be a wait but hope springs eternal..

[Cheshire Freeze]

Just to add to my last post.....some people seem to think that the only way out of this pattern is via a zonal reset. That's not the case at all- if conditions become favourable upstream then it's still possible for a developing Scandi high or pressure rises out west/northwest. A zonal spell will be symptomatic of a poor set up rather than of a gateway to wintry nirvana.

[stodge]

The GFS 12Z Operational centres the HP over western Germany and later Poland by T+108 - if anything the HP is even larger and more intense than on previous output and while the orientation suggests a light continental drift into SE England, the changes thus far have been minor.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2013120612/gfs-0-114.png?12

 

Very intense HP (over 1045MB) over Belarus but a storm over the Middle East serving to prevent a SE'ly movement at this time.

Edited December 6, 2013 by stodge

[swfc]

Id agree with CC there regarding the ouyput.Woudnt it be great if we good get such synoptics"in a rut"with the high to the north!!

[Yarmy]

Something amiss with the UKMO on Meteociel. Either that or incredible consistency!

 

12z T60

 

0z T72

 

 

Edit: Sorted itself now.

Edited December 6, 2013 by Yarmy

[UV-RAY]

Just to add to my last post.....some people seem to think that the only way out of this pattern is via a zonal reset. That's not the case at all- if conditions become favourable upstream then it's still possible for a developing Scandi high or pressure rises out west/northwest. A zonal spell will be symptomatic of a poor set up rather than of a gateway to wintry nirvana.

Indeed but unfortunately for us it's a waiting game and one which may still lead us up the garden path.

[shedhead]

More of the same on the 12 runs so far, very much groundhog day as others have alluded to.  That said I'm still not sure who has suggested they expect a quick return to zonality, slow is how I saw it described earlier and as I said this morning 'painfully slow'.  

[Purga]

Situation worsening with every run

 

Very warm uppers getting in much quicker

 

So far - ca't see it getting any better as the run progresses tbh.

 

And - before anyone starts about 'surface cold' just look at these toasty temps

Sun Headlines ' Phew what a Scorcher' LOL!

Edited December 6, 2013 by Purga

[Cecil Hogmanay Melchett]

More of the same on the 12 runs so far, very much groundhog day as others have alluded to.  That said I'm still not sure who has suggested they expect a quick return to zonality, slow is how I saw it described earlier and as I said this morning 'painfully slow'.  

Im not sure what exactly 'zonal' is,to my mind the set up is about as zonal as you could get with a flat jet and strong PV over Greenland.

Maybe thats incorrect but to my mind the setup is pretty zonal.

[Cheshire Freeze]

About as hideous as you can get in December really. Temps pushing mid teens in places to the lee of high ground. Grim.

 

 

Edited December 6, 2013 by CreweCold

[TSNWK]

12z GFS is a Horror show for coldies. High drifting south west.. We are looking at 2 weeks at least for anything decent if its decent cold your looking for. There is no dressing this up.

[Cecil Hogmanay Melchett]

About as hideous as you can get in December really. Temps pushing mid teens in places to the lee of high ground. Grim.

 

Agreed Crewe,i know its a worn out saying but as IB would say (and my God it used to annoy me),its a long way to cold from there.

[swfc]

Indeed the ukmo does look rather dodgy esp if you go from the 120 to 144 hr chart???gfs 12z looks dire btw

[mountain shadow]

The Northern Hemisphere shows a different picture with a disrupted vortex and Heights pushing poleward on the otherside.

 

Maybe a Northerly down the line?