Model Output Discussion; into 2015

[MR EXTREMES]

Another example of ECM is yesterday's 1055hPa Alaskan High: ECH1-240 (6).gif

 

Tonight's run: ECH1-192 (1).gif

 

We have to accept that any height rise after D8 has a very low chance of verifying especially when there are triggers, like change of patterns, mid-lat lows, Pacific Ridge, etc.

 

I suggest that the experts are well aware of the ECM quirks and use its mean and ensembles as well as other models to work out the probabilities of upcoming patterns. It remains the best op model pre D6 and its ensembles are also the best.

Absolutely agree there is a massive downgrade there of the Arctic high.

No northern blocking although the zonal train looks about the same as our current weather type and the models look like there reloading the same pattern.

As kayro says Matt Hugo seemed pretty down beat also lack of posts by the more experienced speaks volumes to!.

Either it's because the models are not showing anything of interest or it's because they believe the models are not to be believed.

The start event has not really even started yet but I hear a lot about how the models are struggling with the strat effect.

Times ticking poor model outputs tonight.

[terrier]

Well the ECM is garbage tonight. Gfs para has shades of jan 2014 written all over it. No signs of any northern blocking at all tonight. If storms and heavy rain are your thing then your in luck. Sorry can't posts charts as just on my break at work.

[Gibby]

Yes, as I predicted earlier, the ECM has dropped the amplification towards Greenland at T144.

This model really needs to get this problem of over amplification in this area at T168 onwards sorted.

It has gone on for far too long imo.

To be fair the ECM Ensembles never supported the operationals amplification at that time span this morning so I for one largely discounted it this morning. Tonight's evolution is more akin with what I expected to see and is more in keeping with the ensembles this morning. I haven't got the verification statistics to hand but I do know that over time the ECM is well respected and has a high verification status within these time periods and on more occasions than not out performs a sometimes over zealous GFS.

As a footnote I can't see anything notably bad or good in tonight's output be it in the search for cold or particularly stormy weather. It all looks like standard UK Winter fare to me for the next few weeks with the UK lying between High to the South and Low to the North with the standard mix of mild and rainy periods and cooler showery periods in between. Daytime temperature levels will likely reach or exceed average levels in the South at times and fall slightly below in the North at times too with nothing particularly mild or cold either way that is of course after the freeze of the next few days.

Edited December 28, 2014 by Gibby

[Long haul to mild]

We need an objective view of the models - that's often hard in this thread sadly - there is WAY too much cold ramping!!

 

The current pattern (low heights to the north west and high heights to the south) is VERY poor for sustained wintry and cold weather.  Yes, the outputs can change but at the moment nothing significantly wintry on the horizon.

Yes, and there's also far too many silly "winter's over" type comments when it has barely begun. Yes, the models show very little of interest at the moment but maybe they will be tomorrow, or the next day.....

 

We live in a maritime influenced climate so no-one should really be surprised that Atlantic weather predominates in the model output. Some of the best winters I can remember still had plenty of spells of mobile weather. Yes, if you are looking for a two month long blocked freeze-up then maybe that's not going to happen this winter, but let's face it, that really is very rare anyway. I think most of us coldies would take a week long snowy spell (or two) at some point and consider it a decent enough winter.

 

Also, the stratosphere forecasts seem to change as much as the model output, so we can't simply say that because no SSW shows today that it won't tomorrow.

 

Chins up!

Edited December 28, 2014 by Long haul to mild

[dragan]

Very lively weather to come it seems. I cant see any easterly influence for the next 2-3 weeks, i said so 4-5 days ago, and the charts have compounded this. I do think however, in regards to snow, there will be some certainly in Scotland, and perhaps higher ground in northern England.

A lot of folks seem frustrated, but one has to remember how rare easterlies are (and snowy ones even more so) 

[Frosty.]

There is too much over reaction to every run, take a deep breath, take a step back..there that's better.:-)

[blizzard81]

To be fair the ECM Ensembles never supported the operationals amplification at that time span this morning so I for one largely discounted it this morning. Tonight's evolution is more akin with what I expected to see and is more in keeping with the ensembles this morning. I haven't got the verification statistics to hand but I do know that over time the ECM is well respected and has a high verification status within these time periods and on more occasions than not out performs a sometimes over zealous GFS.

As a footnote I can't see anything notably bad or good in tonight's output be it in the search for cold or particularly stormy weather. It all looks like standard UK Winter fare to me for the next few weeks with the UK lying between High to the South and Low to the North with the standard mix of mild and rainy periods and cooler showery periods in between. Daytime temperature levels will likely reach or exceed average levels in the South at times and fall slightly below in the North at times too with nothing particularly mild or cold either way that is of course after the freeze of the next few days.

The op runs should be more accurate at the 144hr - 168hr time frame so imo it puts the ECM in an even worse light.

I keep banging on about this but the ECM needs to sort out it's mid north atlantic height bias - period!

[Catacol]

 

 

Matt Hugo wrote an excellent post on the stratosphere thread yesterday explaining why the current stratospheric warming will not benefit our side of the Atlantic. I suggest people read it.

 

He did - but that isnt quite what he said... and this is not the reality. In the short term it is true that the pressure on the vortex is shoving energy our way. But the very fact that the vortex is under pressure is REDUCING the overall power of the circulation... and in 10 days time we have more top down warming forecast to occur over our sector - giving us the chance of a proper wave 2 squeeze. So for 10 days your interpretation is correct... but beyond that point much may change. Here is the key graphic from today's Berlin diagnostics - with the usual caveat as to the fact that it is of course just a forecast.

 

 

This is no guarantee of automatic cold - but I think it opens the door to possibilities beyond atlantic mobility. Agreed that - until then - we will have a period of alternating PM/TM air with plenty of snow for high ground Britain but only transient opportunities for lower levels.

[Kentspur]

Is it safe to say yet that although we still have a lot of the winter to go through- the winter forecasts by some of the pros are going a bit pear shaped? The change to something more favourable was always predicted to be around Xmas or just after wasn't it? So far the Met office looking good with their " more chance of it being average or above average than below"- Although still plenty of time for that to change.

Lets all just enjoy the next 2 or 3 days of calm frosty weather, and hope the models, strat etc, start to become more favourable for something from the North East or East!

Edited December 28, 2014 by Kentspur

[blizzard81]

He did - but that isnt quite what he said... and this is not the reality. In the short term it is true that the pressure on the vortex is shoving energy our way. But the very fact that the vortex is under pressure is REDUCING the overall power of the circulation... and in 10 days time we have more top down warming forecast to occur over our sector - giving us the chance of a proper wave 2 squeeze. So for 10 days your interpretation is correct... but beyond that point much may change. Here is the key graphic from today's Berlin diagnostics - with the usual caveat as to the fact that it is of course just a forecast.

 

 

This is no guarantee of automatic cold - but I think it opens the door to possibilities beyond atlantic mobility. Agreed that - until then - we will have a period of alternating PM/TM air with plenty of snow for high ground Britain but only transie1nt opportunities for lower levels.

Another trend for this winter - always 10 days away! This started at the beginning of Dec when mid Dec was touted as

the beginning of our winter proper. Well, we are now at the end of Dec and we are still saying 10 days away.

Not a good trend at all!

[swfc]

Tbh folk can only comment on what the mo shows otherwise why view it?i like agood few follow the strat thread ete but it has no guarentee ie ssw,hlb ete!look at the mo and see what is actually there.for the latest ecm looks like the 12z gfs imo and shows the west based pv firing up even tho the arctic-alaskan high are evident.dont like it but its there atm in the forecast.enjoy your evening and have a beer

Edited December 28, 2014 by swfc

[Frosty.]

I hate using the word cool to describe polar maritime incursions with strong winds, it would be cold!! Frequent incursions of 528 dam thicknesses is not standard winter fayre, it translates to cold and wintry at times, I don't agree with gibby.

Edited December 28, 2014 by Frosty.

[Harsh Climate]

Well the ECM is garbage tonight. Gfs para has shades of jan 2014 written all over it. No signs of any northern blocking at all tonight. If storms and heavy rain are your thing then your in luck. Sorry can't posts charts as just on my break at work.

 

I agree the models are dire tonight, unless we get a decent block in place weather that be in the atlantic/greenland/scandinavia we will ALMOST never see any good prolonged/snowy weather.

 

When I look at the charts on wetterzentralle you are hard pressed to see any high pressure cells anywhere on our side of the hemisphere....

[DAVID SNOW]

Is it safe to say yet that although we still have a lot of the winter to go through- the winter forecasts by some of the pros are going a bit pear shaped? The change to something more favourable was always predicted to be around Xmas or just after wasn't it? So far the Met office looking good with their " more chance of it being average or above average than below"- Although still plenty of time for that to change.

Lets all just enjoy the next 2 or 3 days of calm frosty weather, and hope the models, strat etc, start to become more favourable for something from the North East or East!

 I would say not yet: for me anyway the heart of winter is last 2 weeks of jan and 1st 2 weeks of feb, as high summer is last 2 of july  to mid august.

 

So there is     time for the models to start showing some proper cold and snowy weather.

[nick sussex]

A disappointing ECM run this evening but so wildly different upstream from its 00hrs run at relatively short range that drawing conclusions for next weekend remains difficult.

 

Gone is the deep low to be replaced by a weak feature, this looks more like the GFS P 06hrs run, indeed there are differences upstream across all the outputs.

 

It's ironic that as some of the outputs edge towards the ECM 00hrs the ECM changes course. I think sometimes posts in here get lost in translation, by this I mean discussing chances for cold suddenly equates to a pattern change.

 

This then snowballs to a big fall out when the models throw out an underwhelming solution, I think we need to be clear as to what is or is not possible with the current NH pattern.

 

There is very little chance of higher latitude blocking of the robust sort that people think of ie proper Greenland high, Scandi high.

 

The absolute best IMO is some weaker high that could deflect the jet further south and keep the UK with still a chance of some snow. However a deep freeze or ice days the sort that people want to see is very unlikely.

 

Essentially we're trying to get the best out of a pattern that has a few positives but also negatives. So in terms of next weekends weather still a chance of some snow regardless of tonights ECM operational run, because of the divergence upstream I'd ignore all the output past T120hrs, we're not talking here of a divergence that could result in a pattern change, but divergence in terms of angle of the jet, how far south this might be and of course this effects chances of something a bit more wintry.

[IDO]

The strat still shows potential for a SSW in the first half of Jan so the pattern could change very quickly. No guarantee but whilst there are signs of continued warming after the split then we may not have to wait till the last week of Jan. Just a shame the trop isn't favouring our region whilst we wait.

[Captain Shortwave]

Well the odds of a weak high being able to deflect low pressure south of the UK are diminishing tonight, the trend tonight is for good agreement in the mid-term to have low heights stretching from Canada eastwards towards northern Russia. This will put us in a very average spell of weather with a mix of cooler and milder spells along with showers and longer spells of rain at times. At this point again any blocking has tended to set up in an unfavourable position for us in the UK.

GFS ens probably sums up the general trend

[Jason M]

I would understand your comment more if the previous run was brilliant. Problem is, the 00z run was pretty mediocre with

a terrible ending. The 12z run is now much worse. We all talk about trends on here. Well, the trend is bad. I will shout cold

from the roof tops with the best of them given half a chance but I am also a realist. The realist in me tonight says the Netweather

winter forecast looks shaky to say the least.

If we get something late jan / early Feb then I think it would be reasonable to say that the forcast was there or thereabouts. Too early to write off that period. It's a dismal starting point, but not untypical of where we tend to find ourselves going into the new year. No two winters are the same, so opportunities may yet arise. Edited December 28, 2014 by Jason M

[Penrith Snow]

I agree the models are dire tonight, unless we get a decent block in place weather that be in the atlantic/greenland/scandinavia we will ALMOST never see any good prolonged/snowy weather.

 

When I look at the charts on wetterzentralle you are hard pressed to see any high pressure cells anywhere on our side of the hemisphere....

Plenty of charts showing high pressure cells over Iberia!

Models are desperate tonight for the start of January and the tick, tock you can here in the background is winter slipping away.

Andy

[Hotspur62]

Agree that the models don't look good for a sustained cold spell in the short/medium term but as so many people have said in the past looking past 7 days stretches the most super doopy computers and so we still have 2 months of winter left even discounting the next 7 days. At least we haven't got a repeat of last winter which was truly dreadful from a cold pov and many parts of the UK from Midlands Northwards have seen snow. People need to calm down a bit, have a glass of wine/beer and enjoy looking for a cold trend to develop. It will happen this winter and when it does most on this forum will be happy. My preference will be Beast from the East which will penetrate Westwards to cover whole of UK for at least 7 days lol.

[snowbob]

No scientific knowledge in this post what so ever or back up from charts.

But it's only in recent years we have benefitted from cold Decembers isn't it?

Normally as a child our winters were never around xmas.

Always warm and wet as I remember.

Winters over posts are really just pointless at this stage.

And yes I don't post much as I can't back my posts up as well as others but the thread this year is really losing its flair.

I have spent many a year just lurking and learning but at the moment it's just full of snipers.

Anyway back to lurking

[mountain shadow]

So, with model agreement of a positive NAO for the first week and a half of January, Shannon Entropy will drop with an easily forecastable next ten days. From the middle of this week, the Atlantic will move in with wet and windy weather, with wintriness at times over Northern hills and mountains.

After that, we move into the heart of winter and have to hope that the Strat warming will send some HLB this side of the hemisphere, as all the HLB on the other side has served to do is squeeze a lobe of the PV over Greenland, which is never a good thing.

In summary, half the Winter will have gone without any HLB in a favourably area to bring a longer term cold spell to North West Europe, as ever, we watch and wait.

[Frosty.]

[quote name="Kentspur" post="3101607" timestamp="1419793784"

Lets all just enjoy the next 2 or 3 days of calm frosty weather!

[Harsh Climate]

The only straw I can clutch from the charts at the moment is the pressure heightening over towards Alaska and stretching north towards the pole over the next 7 days or so. If we are to get any candy mid-late january I think this could be absolutley key. Can it be stronger and more beneficial than charts are currently showing?? And could it link up with  part of the azores high??

 

 

 

Maybe hopeful thinking but certainly worth keeping an eye on over the coming days : )

Edited December 28, 2014 by Harsh Climate

[mulzy]

I hate using the word cool to describe polar maritime incursions with strong winds, it would be cold!! Frequent incursions of 528 dam thicknesses is not standard winter fayre, it translates to cold and wintry at times, I don't agree with gibby.

 

Hmmm - i would not call the incursions of 528 dam thicknesses "frequent" - there are a few which is very standard for winter.  An objective measure of temperature will be the CET and so far the output for the first week of January suggests an average to above average CET - definitely no freeze on the way.  Yes, things can change after that but for now zonal is the pattern.

 

PS - I agree 100% with Gibby - he's a very objective poster.

Edited December 28, 2014 by mulzy