Model Output Discussion - Staying cold into the new year

[Tim Bland]

Great set of ensembles with the op on the mild side at the end. Hopefully the battle line will be a bit further south meaning snow for more...even south of the M4. Look at the ‘new snow fall’ ensembles pinging for London! 

[V for Very Cold]

More fascinating model watching this morning with a great GFS

hopefully give time for some areas to dry out

how many ppl are reciting the same mantra “get the cold in first” lol

[winterof79]

This seems to have the handle on the snow until Friday

[sheikhy]

Snow chances have pretty much gone for tomorrow and friday for a lot of the country!charts have hardly changes since a couple of days ago but these snow events seem to have just dissapeared!!!

[nick sussex]

We want rid of this mornings ECM nonsense .

That needs to go back under the rock it crawled out from.  It’s an accident waiting to happen , you don’t want any low dropping south that far west .

And don’t be seduced by it’s miracle in bringing the cold pool west . Phasing calamities with shortwave energy flying all over the place and those deepening will see its evolution end in tears .

[Cymro]

27 minutes ago, carinthian said:

I have a bit of an update from the Central European team of forecasting experts. Their charts currently show a strong alignment to the UKMO at 144t.  Looking a head for period 144t -240 they expect a two pronged attack to affect the British Isles during the first third of January. Firstly ,pressure falls in Biscay expected to transfer towards Low Countries with increasing tightening of the isobar flow ( easterly component ) especially for Southern England. Secondly, later in the period pressure falls from the North with a NEly becoming more widespread. The snow computer outer parameter results flags up a increasing snow risk for SE England during this period, marginal at first but becoming more definite later in the period ( possible due to a much colder source of Scandinavian getting established ). Hope this helps.

C

Very interesting how about the rest of the UK any observations on likely impacts for Wales, Northern England, Scotland and Ireland? 

[Kirkcaldy Weather]

1 hour ago, Mr Frost said:

 

Not this old chestnut again. 

Parts of Edinburgh got two inches of settling snowfall with 850HPA temperatures of -2 to -4 the other day! @Kirkcaldy Weather already mentioned this I think - from the North Sea! 

Those snow showers even reached the West Coast of Scotland to sea level...from the North Sea! 

There are many more snow parameters than just 850HPA’s as we all know.

Let’s just see what happens rather than writing everything off five days before a potential chart becomes reality - surely as a snow/cold lover you hope for the best rather than always expecting doom/worst outcome!  

 

1 hour ago, edo said:

 There was an excellent post by @Kirkcaldy Weatherin the previous thread about the weather on the ground from the modelled conditions, uppers of -3 delivered snow off the east 2 days ago in Scotland. Granted there were other factors like the very slack flow but that is the point there are other factors. We all want to see colder uppers but lets not dismiss possibilities solely on sight of 850 temps.

The posters that have continued to go on and on and on about “lack of cold air” is nothing more than being boring at this point now having trawled through pages of the same negative tone for at least a month now, yes the 850 hpa temperatures are no BFTE but if that’s what is expected to magically appear like a Ferrari going 0-60 in 3seconds 99% of the time disappointment is going to happen as that’s abnormal level of cold for UK, I have said before we do not need that depth of cold to get snow just look at this week quite a few parts of the UK have seen what’s probably their best snow for at least 3 winters with 850 temps of between -2 to -4 of course there are other factors involved such as dewpoints which is what stopped me getting snow the other night as I was at 1C dewpoint and sleet whilst just a few miles around me others got good amounts of snow but again that’s how it goes in the UK and I was more than happy to see others enjoying it, for any new members I try to remind myself of a rhyme I made up about the dewpoints “if they ain’t 0 or below u ain’t getting snow”  

The next infamous line to appear in here will no doubt be the “dry easterly” I’m sure a few even thought the BFTE was going to be that if the ECM (and indeed plenty hints of similar from ensembles and other models) is anywhere near correct I would be confident in saying there would be zero chance of it being a dry easterly instead what the ECM shows would be big amount of convective snow setting up with a cold pool getting caught up in the flow and ending straight over the UK 

I mentioned in the Scotland thread last night but I would think there is likely to be differences in the models even at short range for a few reasons 

strat warming 

deep low pressure in Pacific (possibly record strength) and continued intense high pressure to the East / Mongolia which some runs toward the end recently have increased again to between 1060 - 1070 hpa - talk about repeating patterns!

the thing I’m looking for currently is the flow going from ENE - E ^ like those ECM charts, any further than that is likely to have to many differences IMO and I agree with Steve’s comments yesterday the “west based negative nao” comments are going the same way as the “lack of cold air” it’s like any of the big cold spells for the UK really, there is likely to be more than a bit of risk involved in trying to prolong it but I struggle to understand why some in here love being so negative caution is understandable but to try and dismiss any colder weather without backing up such negative views is In balance the 2 I think of with similar kind of evolution in ways is mid December 2010 remember when we briefly went a bit milder then the high went back to Greenland and the PV lobe dropped intense cold over UK , something that hasn’t been too far off on recent runs (again that’s at a stage of modelling likely to change from run to run currently) or the other side of the story think the way the BFTE ended with the setup going west based and the low pushing too far north bringing milder air. 
Currently I see no reason to be pessimistic, slightly cautious perhaps but I’m enjoying watching the models ATM something that hasn’t been common for a good few winters now. 
just using this to dismiss the claims of “lack of cold air” certainly won’t be 100% accurate as no model run ever is especially given everything happening as discussed but last nights 18z gfs fitted the theme I thought was emerging of the ENE FLOW - E then high goes toward Greenland and incoming from the north?  nearly the entire run with the UK in snowfall conducive parameters and any less cold air WAY into the unreliable time frames. 
A simplified video explaining lake effect snow, same basics apply to sea effect snow for UK 

 

[Met4Cast]

Winds are expected to turn more east/north-easterly early next week which could bring some areas into streamer territory. We do have to watch for the warmer N Sea modifying the lower layers/surface layers though, could end up being streamers of rain rather than of snow.

[iowpompeylee]

15 minutes ago, winterof79 said:

This seems to have the handle on the snow until Friday

Nice little curly system over the Isle of Wight New Year’s Eve! 

[Methuselah]

9 minutes ago, Kirkcaldy Weather said:

 

The posters that have continued to go on and on and on about “lack of cold air” is nothing more than being boring at this point now having trawled through pages of the same negative tone for at least a month now, yes the 850 hpa temperatures are no BFTE but if that’s what is expected to magically appear like a Ferrari going 0-60 in 3seconds 99% of the time disappointment is going to happen as that’s abnormal level of cold for UK, I have said before we do not need that depth of cold to get snow just look at this week quite a few parts of the UK have seen what’s probably their best snow for at least 3 winters with 850 temps of between -2 to -4 of course there are other factors involved such as dewpoints which is what stopped me getting snow the other night as I was at 1C dewpoint and sleet whilst just a few miles around me others got good amounts of snow but again that’s how it goes in the UK and I was more than happy to see others enjoying it, for any new members I try to remind myself of a rhyme I made up about the dewpoints “if they ain’t 0 or below u ain’t getting snow”  

The next infamous line to appear in here will no doubt be the “dry easterly” I’m sure a few even thought the BFTE was going to be that if the ECM (and indeed plenty hints of similar from ensembles and other models) is anywhere near correct I would be confident in saying there would be zero chance of it being a dry easterly instead what the ECM shows would be big amount of convective snow setting up with a cold pool getting caught up in the flow and ending straight over the UK 

I mentioned in the Scotland thread last night but I would think there is likely to be differences in the models even at short range for a few reasons 

strat warming 

deep low pressure in Pacific (possibly record strength) and continued intense high pressure to the East / Mongolia which some runs toward the end recently have increased again to between 1060 - 1070 hpa - talk about repeating patterns!

the thing I’m looking for currently is the flow going from ENE - E ^ like those ECM charts, any further than that is likely to have to many differences IMO and I agree with Steve’s comments yesterday the “west based negative nao” comments are going the same way as the “lack of cold air” it’s like any of the big cold spells for the UK really, there is likely to be more than a bit of risk involved in trying to prolong it but I struggle to understand why some in here love being so negative caution is understandable but to try and dismiss any colder weather without backing up such negative views is In balance the 2 I think of with similar kind of evolution in ways is mid December 2010 remember when we briefly went a bit milder then the high went back to Greenland and the PV lobe dropped intense cold over UK , something that hasn’t been too far off on recent runs (again that’s at a stage of modelling likely to change from run to run currently) or the other side of the story think the way the BFTE ended with the setup going west based and the low pushing too far north bringing milder air. 
Currently I see no reason to be pessimistic, slightly cautious perhaps but I’m enjoying watching the models ATM something that hasn’t been common for a good few winters now. 
just using this to dismiss the claims of “lack of cold air” certainly won’t be 100% accurate as no model run ever is especially given everything happening as discussed but last nights 18z gfs fitted the theme I thought was emerging of the ENE FLOW - E then high goes toward Greenland and incoming from the north?  nearly the entire run with the UK in snowfall conducive parameters and any less cold air WAY into the unreliable time frames. 
A simplified video explaining lake effect snow, same basics apply to sea effect snow for UK 

 

And I cannae wait to see some 'puking snow' @Kirkcaldy Weather! Just what the doctor ordered, eh?

[Cold Winter Night]

7 minutes ago, nick sussex said:

We want rid of this mornings ECM nonsense .

That needs to go back under the rock it crawled out from.  It’s an accident waiting to happen , you don’t want any low dropping south that far west .

And don’t be seduced by it’s miracle in bringing the cold pool west . Phasing calamities with shortwave energy flying all over the place and those deepening will see its evolution end in tears .

The reason it drops that far West is the developing high over Scandinavia. To me, that stands out the most this morning.
ECM, UKMO and GFS all make more of that than they did the last few days. A feature to watch in the 12Z's.

With all these uncommon things happening in the atmosphere, from the ground up to high in the Strat, I wonder what kind of surprises we are going to see these upcoming runs. Exciting for sure! Like the good old days.

[Lukesluckybunch]

17 minutes ago, nick sussex said:

We want rid of this mornings ECM nonsense .

That needs to go back under the rock it crawled out from.  It’s an accident waiting to happen , you don’t want any low dropping south that far west .

And don’t be seduced by it’s miracle in bringing the cold pool west . Phasing calamities with shortwave energy flying all over the place and those deepening will see its evolution end in tears .

Hi there Nick I am fairly inexperienced in this model watching,so bare with me you said about ditching the ECM from this morning it may not be as good as the gfs run but it's still showing very cold right just the way it looks is a little more messy?

[swfc]

1 hour ago, MATTWOLVES said:

I quite like the UKMO this morning,looks like large parts of the North under -8 850s.

Matt Hugo saying 5th of Jan looking like the big day,and the trop vortex being in such a state that an SSW was not needed to bring it down,and its more than likely just gonna increase -NAO situation. So I would say get ready for some crazy output to start showing some time next week...perhaps its best to view the current runs with a very relaxed and open mind..a lot is about to happen...Closer to home im being told by the met to expect light snow tonight and tomorrow...what happened to that 500m snow line...lots of changes and dramas coming I reckon.

Great Post man. I think a lot of folk are transgressing to a point. The outlook mabye fluid but all roads lead to cold. Forget the 850s look west at the Atlantic, its in lockdown

[nick sussex]

2 minutes ago, Cold Winter Night said:

The reason it drops that far West is the developing high over Scandinavia. To me, that stands out the most this morning.
ECM, UKMO and GFS all make more of that than they did the last few days. A feature to watch in the 12Z's.

With all these uncommon things happening in the atmosphere, from the ground up to high in the Strat, I wonder what kind of surprises we are going to see these upcoming runs. Exciting for sure! Like the good old days.

The issue is it’s neither one or the other . If the Scandi high develops further and the whole thing gets shunted even further west that’s not bad but a halfway house with low dropping south and phasing with shortwave energy in the Atlantic which blows up a low there and things could turn ugly .

It would be good if we get a clear decision either way by the models. Not a messy halfway house . That way coldies won’t suffer too much stress ! 

[bluearmy]

20 minutes ago, Cymro said:

Very interesting how about the rest of the UK any observations on likely impacts for Wales, Northern England, Scotland and Ireland? 

Too far from Austria!
 

looking at the gefs members later week 2, a complete mess. A mean is all you can work from - and I think that that has little value currently .....

[carinthian]

9 minutes ago, Cymro said:

Very interesting how about the rest of the UK any observations on likely impacts for Wales, Northern England, Scotland and Ireland? 

Hello Cymro, the  fine mesh model snow computer the team use over here is primed for our local area  and produced remarkable results for our village ski slopes within a 48 hour period. With-in its parameters it can produce % indications of expected up a 10 day out period. The SE of England is with-in outer perimeter of effectiveness  but flags up results. Listening to the views of the expects we have contact with over here, I would suggest the cold spell to be widespread throughout the British Isles and think the snow potential would be greatest in the SE during period 6-10 day. However, forecasting is never that easy as frontal boundaries can always align differently. From a Wales perspective , think a front stalling NW/SE would be the chance of significant snowfall coming up against a cold air mass but this is current not showing on the longer term charts, YET !

C

[nick sussex]

5 minutes ago, Lukesluckybunch said:

Hi there Nick I am fairly inexperienced in this model watching,so bare with me you said about ditching the ECM from this morning it may not be as good as the gfs run but it's still showing very cold right just the way it looks is a little more messy?

I tend to view the models and cold weather synoptics with what can go wrong rather than a series of events needed to go right . So margin of error needs to be built in. 

The ECM evolution becomes very messy and has a very low margin for error , a small change in track or depth of that low dropping south and how that phases with mid Atlantic shortwave energy could have a large impact over the UK.

 

[Lukesluckybunch]

18 minutes ago, nick sussex said:

I tend to view the models and cold weather synoptics with what can go wrong rather than a series of events needed to go right . So margin of error needs to be built in. 

The ECM evolution becomes very messy and has a very low margin for error , a small change in track or depth of that low dropping south and how that phases with mid Atlantic shortwave energy could have a large impact over the UK.

 

Yes I agree with you,whilst the outlook remains cold/very cold and blocked if indeed we do get any disturbances moving up from the South we need them to track east southeast.also of we can get a trough moving down from Scandinavia the two will meet and give us a very cold northeasterly,I believe this is most likely scenario back end of next week.I get your concern with the lows moving up from South they could give us the wrap around of milder air from the med that's what we really don't want!so just to conclude the lows of any do occur we want moving east southeast,rather then just stalling

[Lukesluckybunch]

Just now, Lukesluckybunch said:

Yes I agree with you,whilst the outlook remains cold/very cold and blocked if indeed we do get any disturbances moving up from the South we need them to track east southeast.also of we can get a trough moving down from Scandinavia the two will meet and give us a very cold northeasterly,I believe this is most likely scenario back end of next week.I get your concern with the lows moving up from South they could give us the wrap around of milder air from the med that's what we really don't want!so just to conclude the lows if any do occur we want moving east southeast,rather then just stalling

 

[Justin1705]

Hi all. Last time i was in this forum was in the extortionate summer heat looking for thunderstorms. I only really like the 2 extremes of weather. 
 

Anyway, i see you all love the GFS/ ECM but haven't really seen a mention of the CFS i know its long range, and isn't really accurate. But towards the end of the week and beginning of next, it shows an easterly feed from Scandinavia. The worrying thing is that the Icelandic height seem to sleep towards Greenland and get overrun by low pressure in the Atlantic- giving a return to milder conditions . As mentioned above its a great idea to look at the margin for error, rather than build your hopes up to be disappointed. Anyway typing this on my lunch break more to come. Enjoy your days people

[phil nw.]

Coming into the reliable range now is the onset of the easterly by day 5-here on the UKMO.Bringing with it colder uppers and showers which away from the coast would likely produce some snow.The fax shows a trough line on the east coast so looking promising that something more organised may well crop up.

Anyway we will see.
A look at the london ens for 2m temps a cold set again.

We can see a few mild runs around day 7/8 ,this is where the easterly pattern comes under attack from the continental low pressure ,some bringing in milder air-at least for a spell.The 06z GFS op run at t192,a close run thing here.

  

Fortunately these are in the minority and the ecm mean retains our cold pattern further out,possibly renewing it from the north.

ECM mean day 10

Later next week looks quite interesting and dare i say we could well see a decent snow event as the 2 air masses meet.

[MJB]

Be interesting to compare that fax chart ( yesterdays ) with today's when it updates 

[Polar Maritime]

UKV extended also showing an Easterly into the start of next week.

[Pembroke Dangler]

3 minutes ago, Polar Maritime said:

UKV extended also showing an Easterly into the start of next week.

That will feel bitter, cold east wind and temps around 2-4 feeling like -2 -4 in the wind chill brrr seasonal indeed 

[JoeShmoe]

1 hour ago, winterof79 said:

This seems to have the handle on the snow until Friday

The weather warning for Scotland and far north of England for tomorrow looks pretty accurate when you see that . If the marginality falls correctly (big if) could be a snowy NYE for many up here !