Model Output Discussion - 8th - 14th January

[Geordiesnow]

Oh we could, this is the UK- home of the blandest most non-descript weather imaginable to mankind

Of course I could name a few other reasons why I think this winter has been interesting but why bother, it seems like snow is the only weather phenomena that has to occur to make a good winter or not.

Anyways, whilst the ECM is dissapointing in terms of any long term signals with the PV only briefly leaving Greenland, it must be remembered that any Easterly has not yet been showing on the charts but the potential is there which lets be honest for the sake of sanity in this thread, its probably better at this stage we only see some of the pieces of the jigsaw showing but we know the output will swing from way to another but hopefully the ECM is not going to set another trend here and the others are playing catch up.

At least for cold fans, it looks like we might see some colder weather at the end of the week, very little chance of snow due to higher pressure but maybe frost and fog will be a feature which is something that has lacked so far this winter.

[nick sussex]

If people want to take some comfort from tonights output it's the lack of agreement.

The 3 top models all disagree at 144hrs so what the actual outcome might be is still open. We can but hope that the ECM is wrong again as it's pulled out the worst run in tow with its easterly chum the GEM.

Both of these didnt just backtrack but went completely to the other end of the spectrum.

Perhaps they've picked up on a new signal regarding more energy spilling east off the PV and have over reacted or they just went AWOL for a few days leaving the net weather help desk to pick up the pieces!

[ICETAB]

Even though we miss the initial easterly we still have the building blocks for deep cold. I see allot of potential following on from the 240h chart

[J10]

For those wanting an Easterly, certainly disappointment tonight, but the actual likely outcome is far from clear. The huge change around in the models tells us that.

If anyone can find any semblence of agreement between the ECM T+240, and GFS T+240, I'll take my hat off to them.

[Matty M]

That simply WON'T happen in this set-up. The continent is mild which adds significant modification coupled with little in the way of deep cold pooling. It would be a non event for serious cold for most.

All the easterlys that brought sub zero maximum temperatures were from cold already embedded in the NW regions. The charts indicate well the lack of surface and atmospheric cold.

You are utterly incorrect, I am sorry but cold pools can build on the continent at the time of the year in just a few short days, plus they are at -10c or below at this point.

You are posting a complete falsity and you should retract it as it leads to confusion for newbies.

[BARRY]

I wonder what the odds are now of all the models suddenly flipping back to zonal over the next day or two with that theme continuing until there isn't much of winter left at some point in February because I certainly would not bet against it.

Well i would, we are only half way into winter and the signs are tentative but they are there.

[Stuie]

http://www.meteociel...H1-120.GIF?08-0

Nice- a perfect arc over the UK- Also the key is that low, plenty of trough disruption as the jet heads off NE & a peice of energy is sent South-

steve

The notorious camel hump steve?

[Optimus Prime]

Current temperatures across the mainland at this current time has absolutely no bearing on whether deep cold reaches our shores.

Then you obviiously need to have a look at some of the archive charts 1947/1955/1956/1979/80s and 1991 ect. They ALL had deep cold building up across the continent before the cold setup. February 2005 was a perfect example of a perfect set-up which didn't bring the real cold stuff to the near continent until after day 5 of the easterly (2nd March)...by that stage it had blown itself out and only the continent got the type of weather people here want.

It's all conjecture at this stage. An easterly which the models are toying with would not bring distrubtive cold and snow to the UK. Blame the warmest November on record and very mild December for this.

[SMU]

That simply WON'T happen in this set-up. The continent is mild which adds significant modification coupled with little in the way of deep cold pooling. It would be a non event for serious cold for most.

All the easterlys that brought sub zero maximum temperatures were from cold already embedded in the NW regions. The charts indicate well the lack of surface and atmospheric cold.

Irrespective of todays model runs you are a mile from the truth-

A continental cold front ( we rarely see them) will change the surface temps to below freezing in the click of a finger-

The 12z ECM yesterday had the debilt Max at -4 for 4 days on the trot- with thicknesses around 514 DAM-

The only modification would be the North sea & if you had a bare easterly the short hop wouldnt do much damage * IF * we had a long fetch NE over the North sea then your hypothesis would hold some weight-

Today the models overall arent bad tonight & in the grand scheme of the things look reasonable with good polar heights- just more patience needed-

The stratosphere & vortex gradually slow over the next 15 days.. the train will come eventually

Also OP it does show a little lack of knowledge using 2005 as an example to stack up with your arguement in favour of a warm Easterly-

The 2005 developed off the warm side of the jet & had no cold upper air, should things have developed like the 00z then the uppers were ranging down to -15c to the east over a HUGE swathe of area- where as 2005 had a TINY pool of -10c & this was mixed with a huge are of 0--5c air

S

Edited January 8, 2012 by Steve Murr

[kev238]

The runs tonight act as a reality check to some posters (really respected posters) who last night were mentioning feb86 and jan87 on the basis of one or two runs

Back in reality, a mildish week this week.. A cool down by the weekend. After that, anything is possible though a full blown outbreak from the north east is a long shot at this stage.

[weathe20]

Im not sure if the models have shown a decent easterly yet? Just charts that show potential?

[nick sussex]

The notorious camel hump steve?

Unfortunately the hump got flattened! and with it the easterly. Anymore of this from the ECM and it will be sent into the cannon fodder model section. I'd expect this from the GFS which is known for its false promises, you expect better from the ECM.

Even with the ECM imploding who'd want to make a forecast for a weeks time that doesn't go pearshaped by tomorrow!

[SMU]

The notorious camel hump steve?

it was perfect at that stage but the energy behind was / is to flat which was unexpected-

S

The runs tonight act as a reality check to some posters (really respected posters) who last night were mentioning feb86 and jan87 on the basis of one or two runs

Back in reality, a mildish week this week.. A cool down by the weekend. After that, anything is possible though a full blown outbreak from the north east is a long shot at this stage.

Check the disclaimer post

S

[January Snowstorm]

It's all conjecture at this stage. An easterly which the models are toying with would not bring distrubtive cold and snow to the UK. Blame the warmest November on record and very mild December for this.

All speculative but you need only look back to Nov 2010 to see how bitter cold can develop overnight and spill over our shores.

Having cold air in place in Europe, whilst of course welcome, does not matter if the source is cold enough

Where it would matter of course is if we picked up a very slack Easterly flow, becuase the feed then would not be cold enough

So I suppose your half right

[Optimus Prime]

Irrespective of todays model runs you are a mile from the truth-

The only modification would be the North sea & if you had a bare easterly the short hop wouldnt do much damage * IF * we had a long fetch NE over the North sea then your hypothesis would hold some weight-

S

Steve take those blue tinted glasses off lol. I'm telling people how it is (just like the storm back in December) we DON'T have much cold pooling for Great Britain to benefit from. Take a look at the NH 850 isotherm chart;

So please, rationally answer me this question;

Where will the cold come from to support a maximum temperature of 0c in London? Post me a chart to suggest otherwise.

Edited January 8, 2012 by Optimus Prime

[SnowObsessor90]

Well i would, we are only half way into winter and the signs are tentative but they are there.

You're right of course and I probably did go a bit over the top there (deliberately I might add) but still nothing at all would surprise me with the way this winters gone so far.

[Optimus Prime]

All speculative but you need only look back to Nov 2010 to see how bitter cold can develop overnight and spill over our shores.

Having cold air in place in Europe, whilst of course welcome, does not matter if the source is cold enough

Where it would matter of course is if we picked up a very slack Easterly flow, becuase the feed then would not be cold enough

So I suppose your half right

That was a north easterly and at the time NW Europe was already building up the cold. Scandinavia had its coldest November on record I believe.

[Stuie]

At what point between now and FI do we think there is not going to be a cold blast of winter? Being a chilli grower it would be nice to think maybe spring could come early for seeding.

I know everything is in the balance but obviously by the end of the month we should know 1 way or the other?

[SMU]

Steve take those blue tinted glasses off lol. I'm telling people how it is (just like the storm back in December) we DON'T have much cold pooling for Great Britain to benefit from. Take a look at the NH 850 isotherm chart;

So please, rationally answer me this question;

Where will the cold come from to support a maximum temperature of 0c in London? Post me a chart to suggest otherwise.

youve posted a +5 day chart- & 4 days later *IF* the scandi high developed how it was projected in earlier runs it would look like this at Day 9 ( in 4 days)

http://176.31.229.228/modeles/gens/run/gensnh-19-0-120.png?12 DAy 5- Mild ~ 9c in the SE

http://176.31.229.228/modeles/gens/run/gensnh-19-0-204.png?12 day 9- cold front through - uppers around -10 ( not the contour lines are 4 isopleths)

temps driving down to 0c

S

[Jason M]

Sorry OP, but your wrong about this. If a block sets up, within 2-3 days it would be plenty cold enough. Upper air temperatures can change quickly and its important to remember that even under high 850s its never going to be toasty at ground level on the continent in late January.

Massive step back today, but were in a happier place than Friday.

I've looked through the ensembles and we have just about every outcome known to man, so nothings set yet

[Bristawl Si]

The one outstanding fact from the last couple of days model outputs is that even in 2012 computer modelling has its flaws - it seems the world's weather 'experts' are no nearer being able to predict the weather more than a week in advance than they were 20 years ago.

Good to see 'nature' still calling the shots, and not some 'fancy' computer model.

[cooling climate]

That was a north easterly and at the time NW Europe was already building up the cold. Scandinavia had its coldest November on record I believe.

Sorry but you are barking up the wrong tree. If a high at our latitude were to link up with an Arctic high the bitterly cold

air would be pulled down with it and then all you need is a trigger low to pull it back west to us. simple lol I wish.

Take a look at what happens over in the US during the winter months.Same applies here.

[Summer Sun]

Matt Taylors forecast on Country file showed a set-up similar to this for Friday

This could go anywhere from here if the cold air to our east shifted west we would be starting to see some much colder weather.

[Geordiesnow]

I know what OP is trying to say and lets be honest the cold upper air temps on our side of the Arctic has been quite mild compare to normal but if you do see the Arctic high backing westwards it will bring the real Arctic cold with it and whilst we won't see the upper air temps we have seen all those years ago, any easterly should be cold enough for (lying) snow, which lets be honest is what most people want rather than having temps in the minus's but people got different preferences. The Easterly of Feb 2005 was dissapointing temp wise considering the overall set up but it still deliver heavy snowfall and people will chop your hand off to get something like that again really.

That said, the runs in the next few days will tell us where we are going regarding any possible easterly but from all the model runs I seen so far I say an easterly is a small risk because most runs have shown the PV to our North West being too strong for any Arctic/Scandi highs to back westwards enough to have any significant cold affecting us.

[Bristawl Si]

For those interested Ian F's latest tweet says

"UKMO view is of predominately anticyclonic but eventually chllier (but non-snowy) for South UK in next 6-15 days - more unsettled in North though."