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

[Barry12]

Enlighten me then please. I believe we are, if we take the last couple of weeks and current model forecasts into account, its worth serious debate at the very least in my view.My original post ( the bits you choose not to highlight ) invited debate on why we cannot call our current setup a Bartlett, can you do that please if you have time.Cheers.

 

This should help:

 

http://forum.netweather.tv/topic/67869-bartlett-set-up/

[shedhead]

Bartlett or not, there is nothing at all in the model suite so far this evening to suggest anything other than an ongoing predominace of mild weather. No point whatsoever in trying to make a silk purse out of a sows ear, the current outputs are about as dire as it gets for cold prospects - no one has to like it, but we do have to accept it. 

 

 

Edited December 8, 2013 by shedhead

[Purga]

The most inspiring chart of the 12z suits - from UKMO

LOL

Sorry, needed some light heartedness...

[TSNWK]

This should help:http://forum.netweather.tv/topic/67869-bartlett-set-up/

Thank you for digging that out. It actually confirms some of my thoughts, that the current pattern is a Bartlett one, which is in a nutshell high pressure over Central Europe or to the south that is reinforced, ebbs and flows over a period of weeks or months. We have had pattern for at least 2 weeks, I'm sure we can agree that next week is settled... That's 3 with nothing of note in the models suggesting it won't be longer.This will be my last post on the matter, as I might be making myself unpopular and also i don't want a slap from the mods :)Cheers. Edited December 8, 2013 by TSNWK

[The PIT]

Not looking good is it and ending up with a proper Bartlett is the last thing we want too see. I think we can give December a write off as these things stick around. Hopefully ECM won't allow the formation of the beast.

[Weather Boy]

A very curious call on temperatures given that position of HP to the SE, unless they are seeing the HP in a position to bring a Continental influence. I would suggest that it will be much milder than average, probably in all areas and of course wettest in the NW.

 

I disagree, because the forecast range starts at 23 December, which is 15 days away  which is roughly the same as the very farthest reach of the GFS, ie deep deep FI.  It follows that us model watchers have absolutely no idea what the weather is going to be like even at the start of the range, because only one model goes close, and that one is treated with extreme scepticism by the Met at a much shorter range.  We can look at the CFS, but that's it, and it's notoriously unreliable, not surprisingly given its range.

 

The Met have access to powerful long range tools, but even they are just making educated guesses (whereas you and I would be making complete guesses).

 

Therefore, I do not see how you can throw doubt on the met's call so far away when we have almost nothing to facilitate our guesses, except very mundane model output well before that time which could completely change at any time.

 

If the range in question was say, 13 December onwards then I would agree with you, but as it is, none of us have any reason to throw doubt on what the met are saying....although obviously it could be completely wrong given the extreme time range.

 

We do not know what the weather will be like in over two weeks time, simple as that.  Purported predictions for that time period based on nothing are not helpful.

[Tamara]

Yes this is line with the US forecasts of a very +ve AO for January, and obviously +ve NAO goes hand to hand with this, with an intense PV and the downstream Euro High.

We all read various sources to get a picture of what other agencies, websites and professional organisations are thinking but I have yet to see any reputable ones give a definitive proclamation along these lines. There is, actually a lot of uncertainty as one might expect at such a long range - but lets just for a moment examine your statement more closely and put some much needed balance, truth and perspective to these 'US forecasts' you keep mentioning.

 

There is a general belief that the base state of the Arctic oscillation (as a measure of pressure at the pole)  will be fairly positive for the first half of winter, but there is a line of thinking not too different to expert opinion on this site that the pacific ridge will have an increasing role to play as time goes on, and with this in turn changing the profile of the vortex more and more favourably for cold incursions and blocking through wave breaking sequences.

 

Obviously a forecast, so far out, is just that..a longer range forecast..and time will tell if it is accurate or not, but I think if one is going to try and make brief summations with conclusive predictions like you keep doing, then it is best that they are put in truthful context and not skewed to suit a particular personal fad

 

I think we need to be patient with the present pattern and look for signs that the breakdown of the Aleutian High is a transient pattern, so that the jet stream might re-amplify once more. However that question is not going to be answered tonight or very probably for a few more to come too

Edited December 8, 2013 by Tamara תָּמָר

[stewfox]

Not looking good is it and ending up with a proper Bartlett is the last thing we want too see. I think we can give December a write off as these things stick around. Hopefully ECM won't allow the formation of the beast.

 

Why do we keep writing off whole months ?

 

Fantasy Island (FI) must start at its very best at T168 ?

 

Look at FI next sunday I can see the barlett being waived off, thats my take on it re the attached FI model ?

 

The short wave is undercutting/underneath the long wave isnt that what we want to see ?

Edited December 8, 2013 by stewfox

[A.J]

Thank you for digging that out. It actually confirms some of my thoughts, that the current pattern is a Bartlett one, which is in a nutshell high pressure over Central Europe or to the south that is reinforced, ebbs and flows over a period of weeks or months. We have had pattern for at least 2 weeks, I'm sure we can agree that next week is settled... That's 3 with nothing of note in the models suggesting it won't be longer.

This will be my last post on the matter, as I might be making myself unpopular and also i don't want a slap from the mods

Cheers.

don't worry about it, you're doing absolutely nothing wrong as you are discussing the model output, shame more people in this thread can't grasp this concept.....and I agree with you, it looks a classic eurotrash high aka Bartlett High, with the only vaguely interesting synoptic changes happening only in deep FI

[phil nw.]

The Barlett term does send shudders through those of us who remember the past setups of mild Winters.

Really it is just another term for a fairly flat Euro high parked over W.Europe south of the UK in partnership with it's mate the Greenland positioned vortex.

It's pretty much what he have in front of us so call it what we will it does bring us that south westerly setup with cold weather bottled up over the Arctic.

We can only sit this out until some upstream amplification of the jet works it way into the Atlantic pattern to change things.

[Great Plum]

Well, there's much more scatter in the medium term on the GFS ensembles... This is a good thing as it is often a sign of change...

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

[SMU]

Evening All-

 

A disappointing few days model watching, what seemed so promising a week ago actually landed nothing more than a fleeting visit from old man Winter & Jack frost.

 

We did get the scandi heights, but not the Scandi High- which sadly for us is a different scenario for the UK, with mild SW winds on the western flanks.

 

Its going to be a while before we see any cold into the UK...

 

S

[snowmadchrisuk]

All I can add in these situations ,  a positive AO and NAO leads to atmospheric wave train patterns which may have delayed opposite effects – leading to a negative AO and NAO later on in the season . taken from a science website . Of course there are exceptions such as 88/89 Winter. Still let's see if we do end up with a true Bartlett first , The Atlantic could end up being stronger than we think and cause some kind of pattern reset yet.... Obviously FI but quite a few run's lately have wanted to filter Colder air down from the North during the Christmas period so worth keeping an eye on... 

[fromey]

I know its off topic but anyone with sky sports should take a look at the NFL game in Philadelphia,the sort of snow dreams are made of .And they're playing in it.[/quote

How can they play in that, it's insane, would be nice for xmas here

Fromey

[Barry12]

Day 10 on the ECM isn't too bad

 

[BARRY]

Day 10 on the ECM isn't too bad

 

it will change, 4 days is about all we can see with any kind of confidence and then it's not always right.

Edited December 8, 2013 by BARRY

[nick sussex]

My horror rating drops from 9.5/10 after the 00hrs runs to 8/10 after this evenings outputs. That's not saying theres anything wintry on the immediate horizon but slightly less horrifying from a cold perspective. The horror rating stays in effect until theres a tipping point which is 5/10, that will then change to a cold rating!

 

IMO its not the PV blob appearing in its favourite place but how long the models want to leave it there that's the issue, so before we can see any changes we need to see that losing its uniform round shape.

 

The GFS does show it changing at T240hrs but we need to see that in the higher resolution output and then hope that we can see some changes upstream, again though we're just into damage limitation mode at the moment, just a bit more amplification might at least bring a chance of the odd colder shot.

[Barry12]

it will change, 4 days is about all we can see with any kind of confidence and then it's not always right.

 

The mild charts are just as likely to change so it's all good

[Captain Shortwave]

My horror rating drops from 9.5/10 after the 00hrs runs to 8/10 after this evenings outputs. That's not saying theres anything wintry on the immediate horizon but slightly less horrifying from a cold perspective. The horror rating stays in effect until theres a tipping point which is 5/10, that will then change to a cold rating!

 

IMO its not the PV blob appearing in its favourite place but how long the models want to leave it there that's the issue, so before we can see any changes we need to see that losing its uniform round shape.

 

The GFS does show it changing at T240hrs but we need to see that in the higher resolution output and then hope that we can see some changes upstream, again though we're just into damage limitation mode at the moment, just a bit more amplification might at least bring a chance of the odd colder shot.

It might be a case of the polar vortex huffing and puffing for a bit before easing off as we approach Christmas. Whilst I put the chance of a white Christmas as very slim (5-10%), this is based off CFS analysis over the past 6 weeks, there is a chance we could end up with a cold and frosty Christmas. I am quite happy to put a punt of high pressure being near the UK come the big day, actually not deviating too much from the developing weather pattern we are entering. But the CFS is keeping up the trend of the polar vortex not getting fully pumped up and at least allowing some ridging to develop in the Atlantic and pushing through the UK into Europe, offering up some variability in the pattern with some polar maritime and cool continental winds (south easterlies and surface cold).

ECM

CFS for Christmas (put on the regional too with my daily looks at the 12z run)

You can get a good idea (very good confidence) of the longwave pattern here but only small changes can effect the overall surface flow and hence the temperatures experienced. Remember at this time of year there is a huge difference between a south westerly and a southerly (one brings very mild weather and the other brings below average temperatures). 

[cooling climate]

At this point I would say that if the strat charts are looking the same in

another 3 weeks then you virtually right off January as well.

It is of course very disappointing when a good number of posters look

forward to the winter season to see such poor synoptics that in all

likely hood will not improve for the rest of the month. Which will in

affect right off the first third of meteorological winter even though we

are just a week into it.

I know some posters will say how can you say that and where is the proof

but all I would say is the stratosphere forecasts says it and until this

changes then apart from 24 hour topplers at best that is all we can hope

for.

[Frosty.]

Tonight's GEM 12z looks more progressive in the T+240 range than the anticyclonic 00z earlier and shows a colder stronger westerly airflow of polar origins zipping towards the uk. It's still too early to say what it will be like at christmas as it's T+408 hours so there is still plenty of time for something more seasonal to evolve as we get closer to the Big day. 

[bluearmy]

At this point I would say that if the strat charts are looking the same inanother 3 weeks then you virtually right off January as well.It is of course very disappointing when a good number of posters lookforward to the winter season to see such poor synoptics that in alllikely hood will not improve for the rest of the month. Which will inaffect right off the first third of meteorological winter even though weare just a week into it.I know some posters will say how can you say that and where is the proofbut all I would say is the stratosphere forecasts says it and until thischanges then apart from 24 hour topplers at best that is all we can hopefor.

 

cc, you were confident of a cold winter a few weeks back when the strat also looked unhelpful. why have you changed your mind? (ironically just as we get the first consistent whiffs of something high up).

[March Blizzard]

A SSW by definition comes out of the blue, so trying to forecast one is a futile task, surely?

It just highlights how uncertain future weather patterns are. At the moment the Christmas period is looking mild, but this time next week it could be looking bitterly cold. We don't know what is around the corner, we can only guess.

[Captain Shortwave]

As a purely selfish point of view is this evidence enough for me to advise the mother inlaw not to make the 4 mile trip to ours on xmas day,and best she stay put ?

Hmm I dunno, you could always give her the link to exactaweather just in case 

[Methuselah]

Hi Ian, would it be possible to give everyone a link to these US forecasts please ?