Model Output Discussion - The final stretch to Christmas

[snowking]

Gfs12z rain/snow has rain south of yorkshire tommorow

 

GFS at present is still the furthest North solution - not for the first time in these scenarios.

Will be interesting to see the 12z ECM later...after a bucket load more food and wine

SK

[Thunder Snow]

Can we not just push this system a little further north lol, looks like I'll miss all the action. I would post charts to support it, but I have a new phone and have no idea how to lol merry Christmas

[karlos1983]

If I don't stop eating and drinking, there's a good chance I'll sleep straight through any snowy this rate

[Summer Sun]

GFS has some nasty looking lows in FI

 

 

GFS P is taking a similar route as we move into January given that the 850's will be below zero some snow can be ruled out at times and with strong winds some blizzards would be possible over higher ground

 

 

Speaking of snow this the next few days look like our best chance of some snow to low levels

 

 

With the air cold any snow which does fall and lay is likely to hang around for a few days

 

 

Early January sees the snow amounts on the rise again especially in western Scotland

 

 

The precipitation charts show snow for the south at times

 

 

One things for certain some places over the next 24 to 36 hours are likely to see some heavy snow

 

 

Edited December 25, 2014 by Summer Sun

[Harsh Climate]

Here's my take on tomorrows snow chances for low lying areas.

 

 

With the chance of this snow risk spreading a little further south east friday night into saturday as the low pulls away, pulling in some colder air in behind it.

 

.

 

 

I just don't think the south will be cold enough for any snow friday, as the uppers and all important 0Degree Isotherm chart just doesn't support it.

 

 

 

 

But as the colder air digs in behind (saturday morning), I think the south/east midlands should see precipitation turning rapidly to snow with a few cm before the system clears.

Edited December 25, 2014 by Harsh Climate

[Geordiesnow]

Got to say, I'm a tad disapointed just how flabby and weak this NE'ly has got... compared to earlier runs at least, would you even call it a NE'ly anymore or is it just a shallow shortwave heading SE'ly and then the 2nd low finally heads southwards and we end up in a slack Northerly for a very brief period of time. 

 

Still some snow potential and that is a good thing about a more shallow low pressure system, the higher up you are, the more chance really of seeing falling and lying snowfall. I think when the BBC suggests only 2-4CM in a frontal event, then this suggest rain/sleet/wet snow will be seen also and the air over us is not that cold and nor will it of been established for a long period of time. 

 

Longer range, looks too me a rapidly strengthening PV and the Atlantic trying to push in, does not look too much potential going by these latest runs. 

[Thunder Snow]

GFS has some nasty looking lows in FI

 

 

GFS P is taking a similar route as we move into January given that the 850's will be below zero some snow can be ruled out at times and with strong winds some blizzards would be possible over higher ground

 

 

Speaking of snow this the next few days look like our best chance of some snow to low levels

 

 

With the air cold any snow which does fall and lay is likely to hang around for a few days

 

 

Early January sees the snow amounts on the rise again especially in western Scotland

 

 

The precipitation charts show snow for the south at times

 

 

One things for certain some places over the next 24 to 36 hours are likely to see some heavy snow

 

 

BBC keeping it south to

[Banbury]

Certainly no mild weather in the GFS 12z

[Nick L]

ECM has a decent period of snow for the north Midlands tomorrow! A snippet of proper ECM data for you (the red circles on the precip type show heavy sleet/snowfall):

 

Edited December 25, 2014 by Nick L

[snowking]

12z Euro4 maintains a similar track to its 6z run, with similar temperature profiles, with the possible snowfall zone shown on the link below:

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=euro4&MODELLTYP=1&BASE=-&VAR=prty&HH=36&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

Over to the ECMWF to see where it takes the track for tomorrow, but right now the GFS is much further north with this (in to the sort of zone that HC indicated further up)

We have seen these scenarios many times over the years, and in all honesty by this stage modelling tends to go out of the window and it becomes a case of monitoring WV imagery, then later radar imagery to see whether the track and intensity of the precipitation match that of any particular model, or whether it is a nowcasting situation - the latter being the most common.

FWIW Essex Weather Centre highlight the risk of snow in to North Essex by Saturday Morning - but they can only go from the model data and this offers no guarantee that the modelling of the situation turns out to be correct, it could well end up further North or South still at this stage, though I would say generally the margins for error tend to be around 50 miles or so at maximum - that does not preclude unexpected 'extra' developments surrounding frontal systems though.

Over to the ECM

SK

Edited December 25, 2014 by snowking

[kumquat]

Let's face it - the real weather is always a bit south and west of where the models put it in these wraparound lows. Bristol will get hammered with a full one centimetre.

[Stuie]

Ahh those words ringing in my ears "Get ready, it`s coming".....

 

[The Eagle]

Oh dear...

 

[Harsh Climate]

Ahh those words ringing in my ears "Get ready, it`s coming".....

 

 

 

If you live on the eastern side of italy that is

 

 

Not right that they seem to get more convective snow than us..

[Geordiesnow]

Ahh those words ringing in my ears "Get ready, it`s coming".....

 

 

The mild air you mean? Definate trend of a PV strengthning across Canada and with the trend of the states getting much colder then we could see something like last year?

 

Too early too tell and things could change though. 

[Stuie]

The mild air you mean? Definate trend of a PV strengthning across Canada and with the trend of the states getting much colder then we could see something like last year?

 

Too early too tell and things could change though. 

 

Don`t you remember that infamous forum statement? :-) I think the chart I posted is a good benchmark to get to and then go from there.

[shaky]

ECM has a decent period of snow for the north Midlands tomorrow! A snippet of proper ECM data for you (the red circles on the precip type show heavy sleet/snowfall):

 

uk_ec8panel_ec_1412251200_1412262100.png

well.that looks surprising good for places birmigham northwards!! Temps close to freezing and dew points around the same!! Still think its a now casting situation! !

[Banbury]

http://www.meteociel.fr/modeles/ecmwf/runs/2014122512/ECH0-192.GIF?25-0

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014122512/ECH0-216.GIF?25-0

 

Certainly some chillier air over the UK

[Jason M]

Very poor charts this evening. Looking across all the models and ensembles there is about as close to 100% agreement that the high is going to sink as you will ever get. In terms of the medium term outlook (days 6-10) the amount of entropy is rapidly reducing.

Across all the output this evening including GEFS and can find very little evidence of any HLB at all (just a couple of GEFS in FI). Even CFS cant find any cheer.

So, from a trop viewpoint it looks pretty grim. If (and big if) I've understood the signs from the strat thread the future looks pretty positive as we go into Jan. Both can't be right so we are at in interesting fork in the road.

Much like last winter, we don't even seem to be much in the way of eye candy with the deep FI charts. Any deep cold charts have been real collectors items this winter.

Anyway, its Xmas so as the models are playing scrooge, off to find some cheer elsewhere....

[Frosty.]

Cold uppers are not important next week, we will have surface cold, especially those areas lucky enough to get a good snow cover, notice how the timings have been rushed forward and instead of Saturday it's boxing day snow then fine and frosty with high pressure giving the UK a rest from Atlantic muck for most of the week ahead.

[John Badrick]

Oh dear...

 

Oh what a knob!!!!!!

[shaky]

Can you get snowfall with uppers above 0 but solid surface cold in place?

[Aiden2012]

Can you get snowfall with uppers above 0 but solid surface cold in place?

I'm pretty sure the answer is no but someone correct me if I'm wrong lol

I'm pretty sure the answer is no but someone correct me if I'm wrong lol

Just probably freezing rain when it hits the ground

[John Snow]

Xmas day models should be ignored because of the lack of data

If these 12z charts are showing the same thing in 2 or 3 days then worry, not now

[snowking]

ECMWF has very similar track to this below, posted on Twitter from the hi-res NMM output:

This maintains the general trend from today of advertising a generally Wales-Midlands-East Anglia track of the snow threat - once again to stress this does not mean this is the final track, but at present this seems the most likely scenario on the basis of forecast models.

This met office visual firms up on this idea too:

I wouldn't be paying too much attention to projected totals just yet as these situations tend to become pretty dynamic.

I'm off to enjoy the rest of the day - hopefully an exciting day of watching to come tomorrow

SK

Edited December 25, 2014 by snowking