Model output discussion - into 2018

[Frosty.]

If the Ecm is right about next week it will make a mockery of today's update from Exeter regarding next week so perhaps even at this stage, next week we could still be in the battleground between the cold block to the east and the milder atlantic struggling to make significant inroads..more twists to come?..what I will say is if we fail to get the easterly most of us desire, there's a lot of potential for cold zonality to give us the snow fix coldies crave!

Edited January 5, 2018 by Frosty.

[Snowman.]

20 minutes ago, comet said:

At least some good may come out of all this and that being that posters might stop trawling out the lesser models like um GEM perhaps. Although to be fair its been no worse than the ecm. I suppose it also means that the ecm op run has not lost it bias for amplification.

Can we please please please drop the "this model won/lost" crap. I don't come here to trawl through pages of posts after work when half of them aren't even related to the actual weather.

It was a difficult situation, we all know this it was said multiple times. Every model struggled and there was no clear winner only losers, us cold lovers.

Edited January 5, 2018 by SN0WM4N

[Snow Grain]

40 minutes ago, tight isobar said:

I can assure yourself if as modeled that flow takes a-hold you can expect a dip below -8 hpa as the jet dives and that stagnant US- FREEZER , air begin to awash eastward.

Again a very unusual situ unfolding ..

 

Unfortunately the temperature will be too modified by the Atlantic for any interest, especially for those in the south, this is why we all crave a beasterly, it’s the real deal.  PM rarely delivers.

[stodge]

Evening all

Birthday watch for me starts here:

GFS 12Z OP at T+240

ECM 12Z OP at the same time:

GEM 12Z OP at the same time:

Quite like the model agreement and I get a chunk of polar vortex for my birthday. - let's see where this goes.

[I remember Atlantic 252]

3 minutes ago, stodge said:

Evening all

Birthday watch for me starts here:

GFS 12Z OP at T+240

ECM 12Z OP at the same time:

GEM 12Z OP at the same time:

Quite like the model agreement and I get a chunk of polar vortex for my birthday. - let's see where this goes.

Hopefully will create same result as this! very snowy evening here, heaviest snow of season

[joggs]

3 minutes ago, stodge said:

Evening all

Birthday watch for me starts here:

GFS 12Z OP at T+240

ECM 12Z OP at the same time:

GEM 12Z OP at the same time:

Quite like the model agreement and I get a chunk of polar vortex for my birthday. - let's see where this goes.

Turn it upside down and vwala.........your easterly.

[snowray]

52 minutes ago, danm said:

Not really. For our latitude we get very little snowfall. 

The makn reason is not altitude - as someone else pointed out, New York gets much more snowfall than us and is at sea level. New York is also on the western edge of a huge, relatively warm ocean. 

The UK is an island, our waters are warmed by the Gulf Stream, our prevailing wind is from the SW/W, and even when we get cold air from the NW/N/NE &E it is heavily modified compared to other areas of the globe at our latitude because it passes over relatively warm water. 

Its stating the obvious here, but places like Moscow, New York, Toronto, many parts of central and Eastern Europe etc are directly connected to the Artic by a continental landmass. 

The most “continental” part of the UK climatalogically is generally the SE due to its proximity and short sea track to Europe, and distance from the Atlantic. 

Therefore we will always struggle to get deep cold in the UK, particularly down south. So many things need to fall into place! 

Sit back and consider something for a second will you please. Look on a map, can you see Switzerland there, well its just north of the very warm Mediterranean sea. You will also notice the coastal cities of Genova and Nice (Nizza), just north of these cities are the Maritime Alps that rise up pretty quickly, 1000m, 2000m, up to Mt Blanc (Bianco) which is well over 4,000m, here Switzerland starts. Now imagine just for a moment that them there Alps were only as high as the North Downs, or Chilterns, so 200-300m max, do you really think that they would get so much snowfall in that part of Europe that provides for skiing and winter sports uninterrupted from November to April and constant snow cover, by that mild Sea?

I simply don't get how people insist that altitude has got nothing to do with it, the Alps are an extreme example but as we saw earlier it snows in many European cities that are high up, (500-1,000m) and even close to mild seas at times, with uppers that can be as high as +3c. They don't need deep cold do they because they have altitude on their side, where as many parts of the UK struggle to get snow at -5/6-6c at times. Of course I agree with you that our location, the gulf stream, etc don't help much either, but that is only part of the picture.

 

Anyway, ECM seems to be moving in the right direction for some deep cold to be moving this way at last by D10.

[ArHu3]

1 hour ago, danm said:

Not really. For our latitude we get very little snowfall. 

The makn reason is not altitude - as someone else pointed out, New York gets much more snowfall than us and is at sea level. New York is also on the western edge of a huge, relatively warm ocean. 

The UK is an island, our waters are warmed by the Gulf Stream, our prevailing wind is from the SW/W, and even when we get cold air from the NW/N/NE &E it is heavily modified compared to other areas of the globe at our latitude because it passes over relatively warm water. 

Its stating the obvious here, but places like Moscow, New York, Toronto, many parts of central and Eastern Europe etc are directly connected to the Artic by a continental landmass. 

The most “continental” part of the UK climatalogically is generally the SE due to its proximity and short sea track to Europe, and distance from the Atlantic. 

Therefore we will always struggle to get deep cold in the UK, particularly down south. So many things need to fall into place! 

a few reasons are named in this thread:

 

[SLEETY]

On 30/12/2017 at 12:20, tight isobar said:

Ens 6z ..trending cold/very cold.

@london-6z's

Proper deep fetch easterlies in those ensembles

shame they never materialised gfs. No better than any other model

Edited January 5, 2018 by SLEETY

[Frosty.]

Just seen the Ecm 12z ensemble mean, pretty much mirrors the operational regards next week with the atlantic breaking through and some milder conditions at times but then beyond next week there is a trend towards cold zonality as the jet becomes aligned nw / se.

[feb1991blizzard]

Yes op will fit right in the middle of the spread.

[andymusic]

3 minutes ago, snowray said:

Sit back and consider something for a second will you please. Look on a map, can you see Switzerland there, well its just north of the very warm Mediterranean sea. You will also notice the coastal cities of Genova and Nice (Nizza), just north of these cities are the Maritime Alps that rise up pretty quickly, 1000m, 2000m, up to Mt Blanc (Bianco) which is well over 4,000m, here Switzerland starts. Now imagine just for a moment that them there Alps were only as high as the North Downs, or Chilterns, so 200-300m max, do you really think that they would get so much snowfall in that part of Europe that provides for skiing and winter sports uninterrupted from November to April and constant snow cover, by that mild Sea?

I simply don't get how people insist that altitude has got nothing to do with it, the Alps are an extreme example but as we saw earlier it snows in many European cities that are high up, (500-1,000m) and even close to mild seas at times, with uppers that can be as high as +3c. They don't need deep cold do they because they have altitude on their side, where as many parts of the UK struggle to get snow at -5/6-6c at times. Of course I agree with you that our location, the gulf stream, etc don't help much either, but that is only part of the picture.

 

Anyway, ECM seems to be moving in the right direction for some deep cold to be moving this way at last by D10.

This also works in another way - over thousands of years before the age of the computer model - towns and cities were positioned in favoured spots, and part of them being in favoured spots would be that they were less affected by the cold which is more prevalent at higher altitudes, part of the reason why London is where it is and not at the top of the Pennines for eg (the M25 around the Pennines would be a nightmare) - so over those thousands of years, the weather has helped facilitate the growing of these towns and cities in places "less affected" by the cold and snowy weather, with protection afforded by lower altitude or the south side of a group of mountains which gives the town or city protection from wind/snow etc - there are other reasons - economical and political, but weather dictates it too.

[northwestsnow]

4 minutes ago, feb1991blizzard said:

Yes op will fit right in the middle of the spread.

Getting potentially interesting for the hills locally Feb

[Daniel*]

While I’m not going to say this will happen, but the times I’ve seen models go completely off the easterly scent, only for them to go back to it convincingly IMO the best easterlies are the ones that come up unexpectedly. The times in which you have cross model agreement say at day 7, they very rarely go to plan. So fickle.

EC ens mean fully behind OP

It can only get better surely? 

[Captain Shortwave]

It looks like we will see low pressure break through by next weekend.

ECM ens

      

Troughing becoming increasingly prevalent over the UK but with the jet running south of the UK so temperatures will remain on the cool side which means the risk of snow to low levels at times in the north. 

But a big question still remains over the ridge to our east, we could either see this decline eastwards or we could see a cut off high drift northwards, either way we will see low pressure charge in on a southerly trajectory, that said if we do see an area of high pressure develop as a result of that ridge then we could see something more wintry down the line.

[feb1991blizzard]

5 minutes ago, northwestsnow said:

Getting potentially interesting for the hills locally Feb

What timeframe you talking?

[Frosty.]

17 minutes ago, Frosty. said:

Just seen the Ecm 12z ensemble mean, pretty much mirrors the operational regards next week with the atlantic breaking through and some milder conditions at times but then beyond next week there is a trend towards cold zonality as the jet becomes aligned nw / se.

It was a bit lazy of me not to post the charts i was talking about so here they are.

[Daniel*]

6 minutes ago, feb1991blizzard said:

What timeframe you talking?

Day 8 onwards I’d assume. Rather cold PM flow being signalled by both EC and GFS.

 

[TEITS]

On 31/12/2017 at 09:45, TEITS said:

Overall I think the output is great but probably for different reasons than some.

Let me start by saying I remain unconvinced this E,ly will bring as much as some hope for with the exception of N Scotland. I do agree the E,lys will spread S but by the time the low sinks SE the upper temps will be watered down. Currently an E,ly with upper temps of -8C is unlikely to bring snow showers to the E because the warming effect of the N Sea would bring rain/sleet instead.

I am much happier with the overall trend as I shall explain. The ECM beyond +240 would be very interesting because note the Atlantic is heading SE and at the same time colder air is heading S around the right flank of the high pressure over Scandi. The end result is possibly a much colder E,ly later on. Even if the block doesn't hold on and the Atlantic sweeps in, we are still looking at an amplfied jet in the Atlantic and possibly a cold, zonal spell.

I shall have a little ramp here and say in my opinion mid Jan onwards is looking very promising and its only a matter of time the arctic floodgates open from the N or NE or E. I know a front loaded winter was predicted but I see the opposite. The output really has a 1980s feel to it.

Despite the huge recent changes in the models my post above from NYE still stands. Still unconvinced we have seen the last of the changes around the +168 mark especially when viewing the UKMO. However even if the ECM/GFS/GEM are right a cold, zonal spell looks on the cards as I mention above.

[snowray]

24 minutes ago, andymusic said:

This also works in another way - over thousands of years before the age of the computer model - towns and cities were positioned in favoured spots, and part of them being in favoured spots would be that they were less affected by the cold which is more prevalent at higher altitudes, part of the reason why London is where it is and not at the top of the Pennines for eg (the M25 around the Pennines would be a nightmare) - so over those thousands of years, the weather has helped facilitate the growing of these towns and cities in places "less affected" by the cold and snowy weather, with protection afforded by lower altitude or the south side of a group of mountains which gives the town or city protection from wind/snow etc - there are other reasons - economical and political, but weather dictates it too.

Probably one of the most intelligent posts that I've seen on here in some time Andy.

 

Euro4 out. Not showing much for this much shortened cold snap, quite chilly in Scotland though.

 

 

Edited January 5, 2018 by snowray

[northwestsnow]

16 minutes ago, feb1991blizzard said:

What timeframe you talking?

Day 9 owards

Cold zonality..

Edited January 5, 2018 by northwestsnow

[The Enforcer]

32 minutes ago, snowray said:

Anyway, ECM seems to be moving in the right direction for some deep cold to be moving this way at last by D10.

Reverse the Synoptics over the UK and you'll probably have a good picture of what the weather will be like here on 15th January.

[damianslaw]

Perhaps a little too much to ask for a long fetch easterly battling out the atlantic, given the depth of cold spilling out of the eastern USA / Canadian seaboard over the coming days - the high pressure isn't building out from the siberian high or arctic high, its beginnings a response to the trough dropping through the UK - a ridge best way to describe it, but it is set to enlarge quite significantly, just not in the right place or orientation to pull in an easterly flow, and force the atlantic on a NW trajectory.

The main feature that is ruling the roost, is a continued very amplified flow, despite what appears to be a very bullish PV to our NW, all forcing is coming from the NW, and once again the models are suggesting cold zonality by the middle of the month, with the jet aligned NW-SE, is winter 17/18 going to be known as the winter that the Polar Maritime airstream returned.. after years and years of absence it feels. Crucially this time around we will have significant cold uppers spilling into the polar front thanks to the frigid air over NE Canada, the chance of significant snow seems high in my opinion, with low heights dropping through the UK and into central europe, allowing for more robust height developments to our NE. So whilst we look like seeing a fairly average spell of temps next week, another flip to cold and possibly very wintry weather looks highly probable with a set up much more conducive thereafter for the first real chance of northern hemispheric blocking in a position to bring deeper cold uppers from a more NE quarter.

[comet]

Have very little faith in the models right now and although I fully expect the models to show a lot more amplification in the pattern over the coming days I would certainly not be trusting anything the models show at t168 let alone t240 etc.

[ANYWEATHER]

Evening ! Well the Gfs has the Victory  over the recent output as opposed to the little ecm. The Atlantic has won for now ,