Model Output Discussion 29th December - Into mid-Winter.

[bluearmy]

1 minute ago, CreweCold said:

I suppose it is the logical way forward Nick given the way the ops are progressing. There is little to force a change? 

I generally find that  a lack of anomalies is unsustainable. I would be thinking more MLB than zonal although Scotland could be in a  more mobile regime.  wouldn't surprise me if se uk ends up under a slack continental flow

[Timmytour]

15 minutes ago, radiohead said:

About half the 12Z GEFS members develop a strong or very strong low on the 12th/13th. Which isn't even hinted at developing like this on the Op run.

Lokking at P14 if that was pointing the way to one possible evolution and that we ended up with a deep low to our north east that decided to dive south down the North Sea, with the high tides expected around that time, it could end up being quite a nasty little feature.

[MR EXTREMES]

19 minutes ago, nick sussex said:

Exactly, this PM flow lasts about 24hrs and the fact its getting this much attention shows how low expectations have become. Even many of the previous crud winters which were generally mild had a few northerly topplers, what shall we call this sad attempt, for it to be a toppler it at one stage needs to be vertical this is almost horizontal from the start. Unless the ECM can come up with something then the window of opportunity before the upstream pattern flattens out completely looks like delivering a few hours of slush on a hill.

And there strong possibility that it might miss altogether.

The charts are not inspiration for cold at all two days ago we had possible north easterly and pretty potent northerly with neg12 uppers.

Yuck for half the country cold wet.

With as Phil pointed out the bloody azores heights and it can't go far as deep lows to our east and south-east then you look northwest and we got Canadian vortex segment throwing out lows after low.

Tbh its as I suggested yesterday becoming more and more zonal until the azores high tries to establishes across south of England.

[knocker]

15 minutes ago, IDO said:

What are you expecting then? I see little to prevent the PV from getting more organised, so zonal looks favourite. Looking at the GEFS at D16 (usual caveats) and they are insipid.

This evening's GEFS anomalies would certainly support your case and there was nothing yesterday evening to suggest otherwise from the other two. We await tonight's of course but I'll be very surprised if there is much change.

Edited January 6, 2017 by knocker

[radiohead]

Yesterday's 12Z ECM feels like a lifetime ago now...

[Mark Neal.]

Albeit a downgrade on the cold snap from the NW/N. The gfs 12z did still show wintry showers into the NW and N into Thurs 12th + Fri 13th, with rain turning to snow even in the South with cold air well in by the early hours of Fri morning, so still some interest. 

    

We know how GFS precip charts are like and especially a week out! But despite downgrades on the cold snap and longetivity, there is still a window from Thurs for a good 36hrs and potentially into the weekend before the flow gets cut off and high moves in. 

[chris55]

20 minutes ago, nick sussex said:

Lol! If we didn't have anything to moan about then this thread would have about 2 posts an hour! I admire your optimism but the GFS is pants, the 850's will likely be watered down further. Never trust the models 850 projections in PM flows until much closer in. We need more amplification which if by some miracle happened then you might get a shortwave to track se more favourably with more cold air in place. Anyway the ECM might salvage the evening, the UKMO was a bit better than this morning so lets hope the ECM can at least squeeze out a bit more interest.

 Well my optimism was simply highlighting what the 12z run was showing, and the charts i posted were not "pants" as you say, some pretty cold 850s sweeping the country as i posted.

UKMO was looking cold as well with more of a northerly element, 850s would no doubt be colder from that model. Anything past 120 is of course open to change and yes those cold 850s "might" get modified slightly but overall I stick with what i posted as of tonight. 

Lets see what ECM brings eh, watch out for snow Armageddon in SW France  

 

[frosty ground]

5 minutes ago, radiohead said:

Yesterday's 12Z ECM feels like a lifetime ago now...

If only you gave it more than a second thought.

 

So the GEFS are not that simular to the Op run and the UKM is also different to the GFS.... so why is everyone taking get the GFS as gospel?

 

[chris55]

11 minutes ago, radiohead said:

Yesterday's 12Z ECM feels like a lifetime ago now...

Lets see what todays 12z brings

[johnny1972]

1 hour ago, nick sussex said:

Tonights Spam Fritter award goes to the GFS, vile, vile, vile!

The UKMO looks a slight improvement compared to the 00hrs run, but still upstream looks flat at T144hrs. The GEM has more interest but still sinks the high and is never a model to trust.

Overall a very underwhelming evening so far. The ECM to come, we're into damage limitation mode now trying to feed on whatever scraps are left at the buffet table.

Nick

i personally believe looking at the charts since November that something in the background is seriously affecting the winter pattern this year not picked up by anyone inc the MET. It's all scraps as you say and I don't see anything promising at all going forward. For me the last frost I had was end of November and no snow now for a 2nd winter. Not good.

[johnny1972]

56 minutes ago, winterof79 said:

So as I read the thread.....it's all going pear shaped.....it's a mild and wet run and FI is mild too

Good job its FI then as it never verifies and it doesn't look a mild run up to 240 to me.Get a grip girls.It will be much colder later next week and some will get snow....again and after that well who knows.

 

Good job it's in FI? That's were all the cold charts have been all winter for the UK !! Not one cold chart has verified. The euro slug has meandered around our shores all winter. Our cold has headed well north and east. 

[nick sussex]

The ECM at T96hrs looks better over the west USA with a bit more amplitude than the GFS at that time.

At T120hrs the ECM has the best output to the ne with better ridging over Russia, this might help lock the troughing in further west. Upstream cleaner flow with less shortwaves than the GFS.

That area of positive heights circled is important, we want that to work north and put some forcing on the troughing to the west of it.

At T144hrs we have more amplitude over the USA than the GFS.

 

Edited January 6, 2017 by nick sussex

[booferking]

ECM 120 similar to uk model even slightly better. Cold air starting to appear already 120hr mark

Edited January 6, 2017 by booferking

[Pembroke Dangler]

I do get a feeling the models are underplaying the Russian high and it will have its say going into mid month and beyond. Something i afoot that they can't get a handle on.

[chris55]

ECM 120, a very cold pool to tap into for the potential north westerly, modification will occur of course but id say that is on the cold side for a north west airflow source.

[IDO]

6 minutes ago, chris55 said:

ECM 120, a very cold pool to tap into for the potential north westerly, modification will occur of course but id say that is on the cold side for a north west airflow source.

This is D7 and for uppers expect downgrades, but you can see even now moderation in that flow:

As the charts get closer to T0 those uppers rarely upgrade, they usually go the other way. There will be an initially 12-24 hours where we may get a clean cold flow, but that looks as cold as it gets. 

[chris55]

Look how far south and west the 0c isotherm is! On the marginal side for widespread lowland snowfall for the UK, but with a bit of elevation some may be on the money.

 

[radiohead]

1 minute ago, IDO said:

This is D7 and for uppers expect downgrades, but you can see even now moderation in that flow:

As the charts get closer to T0 those uppers rarely upgrade, they usually go the other way. There will be an initially 12-24 hours where we may get a clean cold flow, but that looks as cold as it gets. 

I think you missed Day 6? Surely that's more reliable than Day 7?

[Sawel]

1 minute ago, chris55 said:

Look how far south and west the 0c isotherm is! On the marginal side for widespread lowland snowfall for the UK, but with a bit of elevation some may be on the money.

 

Nothing marginal for Scotland there Chris.

[chris55]

3 minutes ago, Sawel said:

Nothing marginal for Scotland there Chris.

Yes Scotland looks good, with 850s low enough if the ppn comes in for it to fall as snow  

[tight isobar]

An acceptable co-ordination of hp cell links. .

And an' initial incursion of pm/polar air...

Things looking healthy. .as far as possible encroaching of notable cold......

[chris55]

Nice 192, again just on the marginal side for England at least, but not far off!

Edited January 6, 2017 by chris55

[Captain Shortwave]

The ECM isn't as clean as yesterday but it does offer a second bite at getting that arctic maritime air mass in.

   

That low g over the top feeds into the Euro trough and slips south east through the country. Snow to modest levels anywhere along the frontal boundary, though  if it did verify then we might see warm sectors factored in.

Corresponding 850s

   

As you can see the first northerly doesn't really get into the UK, the second attempt should on this run. Of course the initial polar maritime northwesterly at day 6 looks potent enough for northern and western areas.

 

Edited January 6, 2017 by Captain Shortwave

[Seasonality]

12z ecm keeps cold in place better over Europe. Less of the pesky mild air around 12/13 than previous couple runs. Hopefully sub-zero and snow all the way through on this one and no mild wet blip.

[knocker]

A little low forms in the circulation of the main low just east of Iceland on Thursday and rapidly tracks south to be over Liverpool by 06z on Friday. The qusetion is would it bring copious amounts of snow with it if it verified?