Model output discussion 25th Jan onwards

[weather eater]

Yes must admit over the years my biased towards cold has always affected my judgement of the model output although in recent times I have moderated this.

 

One concerning aspect if a bitter E,ly should occur is ice especially if the floods do not drain away in time. Shame I cannot play Ice hockey anymore otherwise I could of played a match on the River Nene here.

Still a big freeze up now and the Fenland ice skaters will have a chance on all those flooded fields, they don't get many chances but they were always on About Anglia when I was in my childhood and youth in the 60s and 70s.

[Tim Bland]

One thing that concerns me is that there isn't 1 single GEFS member that looks aything like the 240hr ECM. Ususaly when the GFS is out of kilter with other models there are still hints in the ensembles that it is open to the idea.  Hopefully the ensebles will be just as infaliable as the OP and will swing today so we have cross model agreement on the Easterly....We can but dream

[Frosty.]

A very wintry spell could be on the way but today we have enhanced severe weather with torrential rain and winds gusting to 100 mph in exposed western coastal areas but as high as 70-80 mph inland. Heavy snow above about 1200 feet across scotland, turning to rain across southern scotland and the central belt but heavy snow continuing across northern scotland hills and mountains, blizzards developing across the hills of northern england this evening and tonight..as if this is not enough, parts of the uk can expect a month's rainfall during the next few days, and some of that will be falling as snow with elevation.

 

The first RED Warning of the winter 

Edited February 12, 2014 by Frosty.

[Ali1977]

Well unfortunately, and I guess as expected the GFS is not following the ECM. One of them is wrong, and this winter it is always the one showing anything remotely cold!!!

[Jason M]

Well GFS just wants another bout of what we have just had.

In fairness the GEFS have resolutely not been interested either. Let's see which of the models is right this evening, though the GFS just seems more likely in truth given the background signals.

[Mucka]

One thing that concerns me is that there isn't 1 single GEFS member that looks aything like the 240hr ECM. Ususaly when the GFS is out of kilter with other models there are still hints in the ensembles that it is open to the idea.  Hopefully the ensebles will be just as infaliable as the OP and will swing today so we have cross model agreement on the Easterly....We can but dream

 

That's true but the thing about the ensembles is that it is hard to know whether they are playing catchup because of their lower resolution or projecting a reasonable probability of outcome regarding our ridge.

So yes they could easily be wrong and slowly trend colder as more and more members pick up on the signal but on the other hand they may be correctly ironing out what is not a particularly strong signal. It is similar to the debate we have in here about mean charts and even anomaly charts to a lesser extent - the easy answer is to take nothing as read and just use our own gut/experience/skill/bravado (delete where applicable) to suggest what the outcome might be. 

Edited February 12, 2014 by Mucka

[bluearmy]

although looking promising for de bilt, the ecm op follows a different solution to the op and brings a mid lat high followiing a sinking se of the trough across the uk

[Mucka]

although looking promising for de bilt, the ecm op follows a different solution to the op and brings a mid lat high followiing a sinking se of the trough across the uk

 

Here are the London ensembes

 

 

Although a cluster go for something briefly colder there is little to no support for this mornings ECM Op which would surely bring ice days from day 10 onwards.

 

And here are the Berlin ensembles where it would surely be sub zero if ECM verified. A little support for a cold plunge to make it this far but not much.

 

Edited February 12, 2014 by Mucka

[bluearmy]

Here are the London ensembes

 

 

 

Although a cluster go for something briefly colder there is little to no support for this mornings ECM Op which would surely bring ice days from day 10 onwards.

 

And here are the Berlin ensembles where it would surely be sub zero if ECM verified. A little support for a cold plunge to make it this far but not much.

 

 

 

Just checked out the same thing mucka. looking at the ens probabilities, a ten percent chance of the -10c isotherm making it to the uk which is a little better than previous suites but not particularly clever. just as the eventual solution several weeks ago was not cold when the vast majority of ens members wanted to be so, the coldies must hope that the opposite is going to be true this time. 

 

however, i would advise that no one gets their hopes up as the 12z approach although as shaun alluded earlier, there does appear a decent shout for a snow event across the central band of the uk as the low slides and fills next week.

[Hotspur62]

Had not looked on this thread for a couple of days as it looked fro a cold perspective things looked pretty bleak with the odds favouring more of the same that we have had for last 9 weeks.ECM  throws up a different solution and if it came off would send this place into meltdown.However,with no cross model agreement am not pinning my hopes on it as it has yet to show this consistently for 3 or 4 runs running. Until(if) it does and it gains support I fear that this winter will continue in same vein as previous 9 weeks. One maybe positive thing is that after this weeks storm batters East Coast of US then things will settle down over there with maybe High Pressure building. This may stop the Atlantic train from early next week and if this did happen maybe the ECM could be onto something . Maybe just wishful thinking on my part and just my interpretation on things. Would show my thinking with maps but do not have the PC skills to do it I am afraid before anyone asks me to back up my reading of matters.

 

As ever in these situations the UK needs a bit of luck and for all pieces of jigsaw to fall in right place if cold does come in from NE but surely we are due a bit of luck this winter. It would be 1st time in 9 weeks if it did lol!!

[Severe Siberian icy blast]

Just checked out the same thing mucka. looking at the ens probabilities, a ten percent chance of the -10c isotherm making it to the uk which is a little better than previous suites but not particularly clever. just as the eventual solution several weeks ago was not cold when the vast majority of ens members wanted to be so, the coldies must hope that the opposite is going to be true this time.  however, i would advise that no one gets their hopes up as the 12z approach although as shaun alluded earlier, there does appear a decent shout for a snow event across the central band of the uk as the low slides and fills next week.

It all depends on the track and shape of the low pressure , the ECM and ukmo have it sliding under a nice clean movement that in the past brings snow and normally continues to prolong the cold spell as once one goes under the rest tend to follow. I feel the low pressure by the 2 big ones has a knock on effect down the line , where's the gfs has it shabby, flabby , and just sits in place for too long mixing the cold out with it . It's unlikely the ukmo and ECM will both be wrong at this time frame but stranger things have happened and judging this winter so far I wouldn't be surprised . And re the ECM ens , i really don't think it means much at this range because as we saw just 3 weeks ago , we had a complete set going very cold , only to vanish 12 hours later , so the ens can be very fickle. Going by the ECM and gem, all picking up the same pattern , and with the ukmo looking identical as the ECM at t144 range you could argue that they may well be sniffing out a major pattern change . But we need to see this built on tonight. The models have been toying and froeing with thiis for a while so we shouldnt be completely surprised by it .

[SMU]

Morning-

 

Well some great runs this morning- however im not convinced at all- Its been a long winter & its taken its toll on the ol' confidence levels- added to that the volatility of the ECM then I think its a case of wait & see scenario.

 

ECM looks great & would go on to be VERY cold for the uk- at day 11 those -20c uppers would be over Germany- 1 more day & .........

 

The other crumb of comfort was the ECM control that's cold at day 12 with ice days.

 

There is strong support for the ECM 'type' evolution today but its the GEM post 144 & the UKMO 144- so right on the cusp.

 

 

Lets see where tonight goes, lets hope a chart like this gets close............

 

http://modeles.meteociel.fr/modeles/reana/1895/archivesnh-1895-2-5-0-0.png

[nick sussex]

Best output of the day so far is the JMA 06hrs run at T84hrs, that looks very good upstream and if you compare it to the GFS for the same time you can see just how much easier it would be to develop a stronger ridge to the north as that low over the eastern USA will be much further west:

 

JMA

 

 

GFS

 

 

Indeed today we have seen a large backtrack from the ECM, putting aside the nice output at the end earlier it has dropped that chunk of low heights that moved across to Norway between T120 and T144hrs, that really was the downer on last nights output so some relief today that its dropped that solution.

 

I would suspect that whatever ECM ensemble members still have that chunk of much lower heights to the north will be totally wrong past T144hrs as they will lead to any ridge being suppressed to the north,so I think those could be giving a skewed picture.

 

There is however low margin for error with the ECM operational run and as we've seen it will be down to the modelling of higher pressure near Svalbard which is really the key, we've seen in the past just how difficult that can be.

 

One positive is that if you move away from the trop and look at the strat zonal winds these do support higher pressure in that latitude, theres quite a reversal of the zonal winds shown so I doubt that the ECM has just plucked an outlandish scenario out of the hat here, the issue is will there be a clearance of any shortwave energy to allow high pressure up there a gap to extend sw.

 

 

You can see there the reversal in the zonal winds at those levels, the issue isn't so much whether high pressure will verify in that area but its impact on the UK.

Edited February 12, 2014 by nick sussex

[mcweather]

Morning-

 

Well some great runs this morning- however im not convinced at all- Its been a long winter & its taken its toll on the ol' confidence levels- added to that the volatility of the ECM then I think its a case of wait & see scenario.

 

ECM looks great & would go on to be VERY cold for the uk- at day 11 those -20c uppers would be over Germany- 1 more day & .........

 

The other crumb of comfort was the ECM control that's cold at day 12 with ice days.

 

There is strong support for the ECM 'type' evolution today but its the GEM post 144 & the UKMO 144- so right on the cusp.

 

 

Lets see where tonight goes, lets hope a chart like this gets close............

 

http://modeles.meteociel.fr/modeles/reana/1895/archivesnh-1895-2-5-0-0.png

 

Yes indeed Steve its a pity that the ECM has given us a number of ghost easterlies in the latter timeframes over the last couple of winters, otherwise we could give this a bit more credence. If it gets down to 120 -144 then I might start to raise an eyebrow.

 

Having said that if those uppers did come our way we could end up with the biggest open air ice rink ever seen in the UK..

Edited February 12, 2014 by mcweather

[Severe Siberian icy blast]

Yes indeed Steve its a pity that the ECM has given us a number of ghost easterlies in the latter timeframes over the last couple of winters, otherwise we could give this a bit more credence. If it gets down to 120 -144 then I might start to raise an eyebrow.Having said that if those uppers did come our way we could end up with the biggest open air ice rink ever seen in the UK..

I know lol, imagine what 850's of -15 with nights below -10 would do to them flooded acres upon acres of land . We could end up with severe lake affect snow generated by the new lakes lol , now that would be fun haha. I'm just joking by the way before some snow starved mad person on hear thinks I'm on to something !!! Edited February 12, 2014 by Severe Siberian icy blast

[Mark Bayley]

Hopefully something like the ECM occurs because if we get anything like the GFS 6z then flooding is going to remain a real problem and if not worsen. A further 40-50mm rain by this time next week for those areas affected, more in the west.

Edited February 12, 2014 by Mark Bayley

[Timmytour]

Such is the battering we've taken this winter, a promising ECM is being treated with a degree of scepticism rarely seen before.  I'm not even sure the Daily Express would chance a forecast on it these days!

[Trom]

Well GFS 6z really gives no respite in the rain for the next two weeks in the South. 

[bluearmy]

 

 

The other crumb of comfort was the ECM control that's cold at day 12 with ice days.

 

 

 

 

 

under a mid lat high that drifts down from the north behind the trough sinking se.  not the same evolution to the op.

 

the ecm is not isolated if you are looking at the x model ops. it is if you are looking at the ens guidance. winter on the backburner remains the strong favourite (apart form shaun's possible snowevent next week)

[weather eater]

Yes the 06z fails to back up the ECM but I'm far more interested in the 12z and the UKMO, will they back this morning’s ECM, will this evenings ECM show some continuity with the earlier output. Meanwhile I see the METO have issued some red warnings for parts of the coast of Wales and NW England, it’s certainly gusty here now that the front has gone through. Got distracted doing this post by a Game of thrones season 4 trailer, looking forward to that.

Edited February 12, 2014 by weather eater

[johnholmes]

looking at the 00z synoptic outputs and how likely they are to validate in my opinion

 

The synoptic charts for about 144h ahead- 12 feb 14.pdf

[Frosty.]

A months worth of rain during the next few days is a frightening prospect on top of all the current severe flooding, but that's what the models are showing. 

[weather eater]

A months worth of rain during the next few days is a frightening prospect on top of all the current severe flooding, but that's what the models are showing. 

And as its quiet I just picked this up from the BBC

 

A disturbing picture of flooded Britain is revealed in new figures about the saturation of the ground. The British Geological Survey runs 32 boreholes across the country and an astonishing nine of them show record water levels. One has never been so full in its 179 years of operation.

The scientists analysing the data describe it as extraordinary. And these high levels are not just of scientific interest. They mean that the ground is at full capacity, so any more rain inevitably means more flooding. Readings from the rivers are equally alarming. Of 65 river sampling stations, 17 have never seen such high average flows for January. And the worrying development is that these exceptional flows have lasted so long and are likely to continue.

The last thing anyone needs now is more rain but that's exactly what's forecast. As one scientist at the Centre for Ecology and Hydrology put it: "There's literally nowhere for more water to go - the ground is full." That can only worsen the great pulses of floodwater now heading downstream. Most floods are short and severe; this one is in a long-lasting and hazardous league of its own.

[mcweather]

looking at the 00z synoptic outputs and how likely they are to validate in my opinion

 

The synoptic charts for about 144h ahead- 12 feb 14.pdf

 

Hi John

 

Genuine question

 

Just out of interest how good are the anomaly charts at picking up changes when the atmopsheric situation has been stuck in a rut for weeks on end?

Is it possible that once in a blue moon the operational nwp might be quicker to respond to a possible change.

[johnholmes]

Hi John

 

Genuine question

 

Just out of interest how good are the anomaly charts at picking up changes when the atmopsheric situation has been stuck in a rut for weeks on end?

Is it possible that once in a blue moon the operational nwp might be quicker to respond to a possible change.

 

They are usually very good and much better in my view (others disagree) than the synoptic models. If the 3 are very similar over about 3 days to each other and consistent then about 70% accuracy at 500mb. The clever bit then is to try and get the surface pattern close.

Yes I can think of one instance when the synoptic models consistently showed a change before the anomaly charts but just the one I can recall in 4 years daily watching throughout each year.