Model Output Discussion - 14th Jan 12z Onwards

[IDO]

The control for the slider stalls the front in the west, probably the most likely scenario, with the main snow north of the M4 in a narrow band:

 

 

That area could see 24 hours of snow if that verified. Again one of several options going forward.

[bluearmy]

Sorry BA was referring to the 06z ensemble cluster that had the fast track easterly rather than the op's slower progression. GEM looks like it is also seeing the faster evolution:

 

T138: gem-0-138 (1).png

Cluster? That's different then !

Still probably progressive though a fat sausage MLB quite feasible for a few days and depending where it sits, could be frigid uppers or fairly benign.

[Mucka]

Given the variety of solutions on offer in GFS ensembles in relatively short time-frame I think it will be a while before this slider is modelled consistently and until then FI is probably T96/120

 

 

Also we will be relying on MLB as there is no HLB on offer so the placement, orientation and latitude are key from the mid term, none of which have been resolved.

Edited January 15, 2015 by Mucka

[IDO]

I wonder if the GFS is up to its old tricks as this is a very progressive suite with the control sinking the high at D8: 

 

 

The GEFS at D8 certainly not very promising: 

 

See what direction ECM moves?

[pointswest]

A few posts have been removed- one off topic and the replies to it.

 

Please think before you post in here and make sure you are on topic- especially so now we are very busy.

 

Any problems with a post please report it and leave it for the team to deal with as replying just adds to off topic content

 

Thanks everyone.

Hands up!! Very sorry. 

[Mucka]

GFS short ensembles Central England. (Obviously some data corruption regarding the Op plot)

 

[marksiwnc]

The key difference with 12z GFS versus it's preceding run is the modelling of a closed circulation and moreover, running this further south. Despite the initial awkward and finely balanced forecast rain-sleet-snow phase in much of south, this current prognosis would then readily entrain colder boundary layer around N-NW flank and - depending on how this phases with occlusion remnants/forcing/WBFL - would readily give snow for a while as the centre moves S. However, it duplicates various earlier ENS members so albeit a plausible outcome, remains but one of many - some more nuanced than others.

Having looked at the shape of the low on the 12z and 6z and being in North west Wales on low ground how would the precipitation fall as?? Or how do the met currently see things paning out for midlands and Wales in all??

[Long haul to mild]

GFS short ensembles Central England. (Obviously some data corruption regarding the Op plot)

 

Very good agreement there, only three members ever go above 5 degrees and only very slightly then. Ice days and snow definitely on the cards next week, but the details of where and when the snow will be will keep changing from run to run so hang on in there everyone!

[kev238]

We are always told get the cold in and snow opportunities will emerge.

It is clearly going to get colder- not exceptional cold- but just after Xmas wasn't exceptional cold and delivered a good fall of snow for a strip of the country.

[alexisj9]

Yes I'm well aware of that, which is why I said it, it was in reply to someone saying the further into winter the harder it is to get convection off the North Sea, I was merely saying that it shouldn't be hard as the sea temps are high.

oops sorry didn't see the other post.

[Downpour]

I wonder if the GFS is up to its old tricks as this is a very progressive suite with the control sinking the high at D8: 

 

gens-0-1-192 (2).png

 

The GEFS at D8 certainly not very promising: Meteociel_-_Panel_GEFS 20.png

 

See what direction ECM moves?

The fact that IDO is looking for milder solutions at Day 8 tells its own story. 

 

Good model runs so far today.

 

Eyes down for the ECM. 

[legritter]

How much do I hate these 4 little words when you keep hearing probably rain....

" South of the M4"

But to be fair I'm no expert but the charts look like we will all get snow at some point during the next few days. â„â„â„â„â„â„â„

yes  very good looking potential for next week ,Fantastic charts and many posters in with a good chance of snow ,i must admit ,[south of the m4 ]is fast becoming a very annoying saying to me ,from my IMBY perspective ,tonights charts eagerly awaited ,perhaps met office could include the m4 corridor on their charts ,catch up later all .

[Mucka]

Another observation on GFS ensembles but a positive one.

We know the cold spell is relying on MLB and to get sustained cold past 6-8 days without any HLB forming requires quite a convoluted set of twists and turns all in our favour.

This is why generally we see breakdown being modelled as well as the models natural trend toward a more mobile pattern.

But what strikes me as I run through GFS ensembles even where the breakdown is modelled quite quickly(relatively,s till a good cold spell)  is that the Azores High generally remains displaced and further cold shots look inevitable.

I wouldn't be surprised to see an even stronger cold spell being modelled early February.

 

Please don't take this post as searching for a breakdown etc, that is nonsense. It is just a look ahead to the longer term trends and if you aren't interested fine, jog on baby.

 

Full ensembles GFS Central England

 

 

Any warm up looks very stilted and perhaps temporary on those does it not?

Edited January 15, 2015 by Mucka

[winterof79]

Good afternoon all. Just looked at the 12z GFS and wow there's some snow potential there. Crikey.

As ever, and in homage to an old old poster on here Stratos Ferric: the devil will be in the detail, but how's this for a pretty picture?

Further ahead, I do confess to finding it bemusing, as indeed before Christmas (when I lost my rag about this), that there are some who spend their time in the far realms of FI having already wished away the next week of cold and who have, apparently, decided the game is up because a chart on a run at T240, or whatever, says so. Reliable timeframe always used to be considered out to T168. Well the chart at T168 looks none too shabby to me:

Good afternoon all. Just looked at the 12z GFS and wow there's some snow potential there. Crikey.

As ever, and in homage to an old old poster on here Stratos Ferric: the devil will be in the detail, but how's this for a pretty picture?

Further ahead, I do confess to finding it bemusing, as indeed before Christmas (when I lost my rag about this), that there are some who spend their time in the far realms of FI having already wished away the next week of cold and who have, apparently, decided the game is up because a chart on a run at T240, or whatever, says so. Reliable timeframe always used to be considered out to T168. Well the chart at T168 looks none too shabby to me:

Hi West,

What time frame is the snow projection chart you posted?I'm on my phone and its not clear.Also is that the disturbance that has moved down the country?

Cheers

Jason

Edited January 15, 2015 by winterof79

[Duane S.]

The usual pre-cold spell madness on here ensues. Putting aside the usual 1 or 2 hellbent on delivering (unfounded) bad news to us snow starved UK snow hopers, why do others never learn in respect of snow chances? In my location, if I can refrain from the completely pointless task of micro analysing ever single op run for whether it may or may not snow in xx place in xx number of days, I'm sure most of you in more primed geographical locations can as well.

The bigger picture for an at least 7 day cold spell is all that matters, that looks great at the moment. With good agreement on a slowly decreasing low pressure anomaly sat beneath us will stack the odds in our favour in respect of both increasing the longevity and severity of the cold spell, that's really all that matters. The will it snow, won't it snow in my town, as has always been the case, will have to wait for 24 hours prior at best, nowcasting at worst.

It's worth remembering it is extremely rare to get one 'event' giving snow UK wide and I don't see that being any different with this setup. There will be losers and winners but the good news is, there looks to be a few 'events' in the offing with this impending setup, so chill out, relax and just enjoy the fact we are about to have a decent countrywide cold spell for the first time in nearly 2 years!? Where there is potential... And even if it does all go the way of the pear, it's still only mid January, plenty of winter left to go...

Over to the ECM to deliver a beauty of an Easterly ??

[bluearmy]

Theme of the GEFS week 2 is further trough disruption and sliders,

Other variations on the table but given the anomolys and ecm eps , I think more of the same out to day 12 at least

Edited January 15, 2015 by bluearmy

[throwoff]

Definate upgrade for SE, from Sunday onwards we are looking like a bit could hit kent.

[shaky]

Please please ecm dont ruin the good mood in here otherwise all hell is gona break loose! !here we go so it begins......

[ian34]

The usual pre-cold spell madness on here ensues. Putting aside the usual 1 or 2 hellbent on delivering (unfounded) bad news to us snow starved UK snow hopers, why do others never learn in respect of snow chances? In my location, if I can refrain from the completely pointless task of micro analysing ever single op run for whether it may or may not snow in xx place in xx number of days, I'm sure most of you in more primed geographical locations can as well.

The bigger picture for an at least 7 day cold spell is all that matters, that looks great at the moment. With good agreement on a slowly decreasing low pressure anomaly sat beneath us will stack the odds in our favour in respect of both increasing the longevity and severity of the cold spell, that's really all that matters. The will it snow, won't it snow in my town, as has always been the case, will have to wait for 24 hours prior at best, nowcasting at worst.

It's worth remembering it is extremely rare to get one 'event' giving snow UK wide and I don't see that being any different with this setup. There will be losers and winners but the good news is, there looks to be a few 'events' in the offing with this impending setup, so chill out, relax and just enjoy the fact we are about to have a decent countrywide cold spell for the first time in nearly 2 years!? Where there is potential... And even if it does all go the way of the pear, it's still only mid January, plenty of winter left to go...

Over to the ECM to deliver a beauty of an Easterly ??

Tut tut mods feel free to remove I do not post on here much prefering to sit on the fence and watch from behind the scenes and leave it to the most experienced on here,i do feel that the mod thread is fast becoming the south thread,when a person from the north west comes in and gets slated for commenting the north west is gping to have loads of snow,i do feel the mods need to get a hand on this it is very much becoming imby yet again.Thanks

[IDO]

The clusters at T156 show there remains a split as to the GEFS whether they go the fast track to the easterly or continue with the Euro trough:

 

 

So difficult to glean much from this run as it cannot go both ways. More runs to see if the trend continues.

[captaincroc]

The games begin on Saturday

 

 

Snow for the north and south if the GFS is correct.

 

This chart for me sums up why we shouldn't look too far ahead in regards to snow and where it is forecast. A day or so ago the wind wasn't as 'Northwesterly' so the Cheshire Gap posse had no snow forecast (Trust me, I have been watching these charts! ) and now a slight change in wind direction has caused hours of potential showers coming down the gap..... in less than 48 hours away.

 

Hold on to your hats people, it's nearly play time. 

[SMU]

Possible snow for the South west ( & poss southern extreme counties ) on Sun

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015011512/ECU1-72.GIF?15-0

 

on the ECM that's rarely wrong at 72

 

S

PS- also snow in eastern Scotland drifting South

 

The UKMO T 60 now updated shows SUB -5c dewpoints within that polar air

http://img.meteocentre.com/models/ukmet_eur_12/TS_TS_PN_060_0000.gif

Edited January 15, 2015 by Steve Murr

[dec10snow]

Tut tut mods feel free to remove I do not post on here much prefering to sit on the fence and watch from behind the scenes and leave it to the most experienced on here,i do feel that the mod thread is fast becoming the south thread,when a person from the north west comes in and gets slated for commenting the north west is gping to have loads of snow,i do feel the mods need to get a hand on this it is very much becoming imby yet again.Thanks

I think what it is, is that when people post PPN charts and say things like 'UK snowfest', it can get a bit irritating (speaking for most of us SW'ers at least) when we don't actually have any sign of snow, and will be all rain for us... Some people appear to forget about the SW.

The problem becomes when people post charts with a similar theme to 'snowfest' above, and it's a pressure chart, not a PPN one. This can lead to less experienced members getting mislead believing we're having countrywide snow, if they can't read charts well, when in reality... It isn't countrywide!

[shaky]

Ecm off to a good start that low is getting ptetty close to the south of the uk and wasn't there on yesterday's 96 hour chart! !

[gottolovethisweather]

GFS short ensembles Central England. (Obviously some data corruption regarding the Op plot)

 

 

After a quick glance at the above, put simply, from midnight tonight Temperatures will be lower than any point in recent times right through to the 23rd January should the above verify (and why shouldn't it?). Temperatures will definitely well below normal and cold enough for snow on most days even during daytime by the looks of it. For central England as good a region of choice to represent snowfall chances inland as anywhere imo, these ensembles indicate that the following timeframes will be ones to watch. The evening of Saturday 17th January, Tuesday 20th January mid-afternoon onwards and Wednesday 21st January (Happy Birthday gtltw  ) reflect the greatest snowfall opportunities currently. This is not to say there will not be further opportunities for snow and hopefully lying snow options outside of these timeframes, equally we need the colder air to verify as shown too, alongside hope of lower 850s to avoid any transient events. 

 

The downside to my analysis is that this simply represents one region of the country, but let's be honest, if it can snow that far inland, other regions exposed to the Northerly/North Easterly will also benefit from forecast events too. A final suggestion from me and as stated by others Tuesday's event (potentially the second snow event by then at least) is not nailed yet and currently represents the beginnings of FI. We will know more about such local/regional variations of specifics nearer the time, by following updates in the coming days.

 

Cheers and here's to at least some harsh Air frosts if nothing else, since I've only had one since the start of the year. Let it snow, let it snow, let it snow.  Sorry mildies.   

Edited January 15, 2015 by gottolovethisweather