Model Output Discussion 01/09/17

[Man With Beard]

EC ensembles D10/D11 ... heights to the north and pretty much anything goes apart from that. Lows to the west, lows to the east, lows on top of the UK ... no clear direction whatsoever this morning.

[booferking]

8 minutes ago, Man With Beard said:

EC ensembles D10/D11 ... heights to the north and pretty much anything goes apart from that. Lows to the west, lows to the east, lows on top of the UK ... no clear direction whatsoever this morning.

Well at least we've got heights to are north that's a start.

[karlos1983]

46 minutes ago, blizzard81 said:

The trouble is though these charts are sticking at day 10. We really need to see them come down to day 9, 8, 7 etc. This hasn't happened over the last couple of days. 

True but....  I'd rather them being shown at D10 than not at all. I think we will see all options being played out over the next few runs, but currently the way I see it, we are still very much in the game!!!    Could be my inner Arsenal coming out........ (don't read that wrong ) ever the optimist..

[stainesbloke]

51 minutes ago, blizzard81 said:

The trouble is though these charts are sticking at day 10. We really need to see them come down to day 9, 8, 7 etc. This hasn't happened over the last couple of days. 

This happens through much of summer too, with any interesting weather constantly kept at the 10 day range in models. 

[sundog]

1 hour ago, blizzard81 said:

The trouble is though these charts are sticking at day 10. We really need to see them come down to day 9, 8, 7 etc. This hasn't happened over the last couple of days. 

I think after all the fuss this episode will end in a few days of cold weather ,some snow for the hills and that will be that until the next window for cold happens imo. I hope its something more then that but the really good charts always remain out of reach so because of that im not too excited by it all.

[Summer Sun]

Feeling cold over the next few days then turning milder from Tuesday to Thursday away from Scotland

Friday see temps falling again

Saturday sees temps rising from around South Yorkshire southwards

 

Looking deeper into GFS and it has some pretty high temps on offer for the south especially at times whilst Scotland holds onto the colder air

Edited November 10, 2017 by Summer Sun

[carinthian]

Stunning morning on our mountain. This taken on the Aineck top runs. Have high spatial resolution of 1x1km ( village boundary at height 1650m ) analysis for forthcoming snowfall amounts for period Sunday night ending 9am Monday. Total prediction is 16cm but increases significantly with height. Freezing level drops from 2100m early Sunday morning down to 400m by Monday afternoon. Portal predictions indicate that this could be an underestimate as the frontal wave crossing Southern Britain on Saturday is likely to be over the Alps later on Sunday and could intensify the precipitation, so later resolutions will be looked at with interest for us. Pressed on the longer term trends, they seem to favour ECM outcome over GFS by day 10  with the Low pressure dropping south under the presence of higher latitude blocking. That will do fine by me, but as always GFS has a good record of picking up a change in trend. As always we will see . Anyway, hopefully that warm sector associated with the wave is short lived and not erode much of this precious snow base we have to build. Its looking good.

 C

[karlos1983]

3 minutes ago, carinthian said:

Stunning morning on our mountain. This taken on the Aineck top runs. Have high spatial resolution of 1x1km ( village boundary at height 1650m ) analysis for forthcoming snowfall amounts for period Sunday night ending 9am Monday. Total prediction is 16cm but increases significantly with height. Freezing level drops from 2100m early Sunday morning down to 400m by Monday afternoon. Portal predictions indicate that this could be an underestimate as the frontal wave crossing Southern Britain on Saturday is likely to be over the Alps later on Sunday and could intensify the precipitation, so later resolutions will be looked at with interest for us. Pressed on the longer term trends, they seem to favour ECM outcome over GFS by day 10  with the Low pressure dropping south under the presence of higher latitude blocking. That will do fine by me, but as always GFS has a good record of picking up a change in trend. As always we will see . Anyway, hopefully that warm sector associated with the wave is short lived and not erode much of this precious snow base we have to build. Its looking good.

 C

That looks stunning @carinthian what a great start to the season for the Alps, nice firm pack I'd expect now? 

I guess favouring of the ECM D10 comes as no surprise due to it's performance at that range, but you are quite correct, the GFS does have a nasty habit of picking up a change in trend, lets see what the 06z throw out, hopefully it was just a rogue in the vast variety of options currently on the table. 

[carinthian]

6 minutes ago, karlos1983 said:

That looks stunning @carinthian what a great start to the season for the Alps, nice firm pack I'd expect now? 

I guess favouring of the ECM D10 comes as no surprise due to it's performance at that range, but you are quite correct, the GFS does have a nasty habit of picking up a change in trend, lets see what the 06z throw out, hopefully it was just a rogue in the vast variety of options currently on the table. 

Hi Karlos1938, I am really excited with present conditions. Its does take a bit more time to compact, maybe after Sunday night top up. Ideally followed be a period of below freezing temps to solidify the fresh snow and regular top up with the man made stuff ! Yes the GFS is a worry as warmth would be thrown into the equation and that's not good for the Alps or many of cold lovers back in Blighty. However, UKMO possibly trending with ECM outcome at day 10, that's what they seem to think over here .

[bluearmy]

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

[karlos1983]

3 minutes ago, bluearmy said:

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

Exactly BA, please someone tell me what is wrong with this chart at D8... not seeing any PV lobe in its favourite location, in fact the PV doesn't have an identity at D7 never mind D10!!

[ICE COLD]

3 minutes ago, bluearmy said:

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

Yes BA had to bite might tongue reading some of the posts this morning saying that things are downgraded. Nothing's been  downgraded as you rightly say ECM days 7,8,9 and 10 looking ok . It could be a lot worse ? 

[karlos1983]

GFS 06z none to shabby at D8 either

looking like a better run in comparison to it's 00z

[booferking]

6 minutes ago, ICE COLD said:

Yes BA had to bite might tongue reading some of the posts this morning saying that things are downgraded. Nothing's been  downgraded as you rightly say ECM days 7,8,9 and 10 looking ok . It could be a lot worse ? 

Yea no downgrades in my eyes 7 days away chance for snow for some as the front pushes south cold air follows quickly behind back-edge snow possible.

Edited November 10, 2017 by booferking

[Chesil View]

Just now, bluearmy said:

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

Quite so BA. If someone offered us at the beginning of September the chance that we'd be going towards December with the PV in bits and high pressure all over the polar regions. We'd have pulled their arm off.

[Singularity]

The movement in the trough in the W. Atlantic is probably one of, if not the major driver behind the wide variability in height anomalies seen in the ensembles at the moment.

GFS 06z has a shallow shortwave low splitting off this and running into the base of the UK trough next Saturday and this seems more realistic to me than the wholesale eastward movement of the trough from the W. Atlantic that then follows. 

With the jet in such a wavy configuration, eastward propagation ought to be limited, if any... or am I thinking about this wrong?

ECM 00z did a better job of holding the trough back, but still looked a bit iffy by day 10. 

It's essential that this happens, because for one thing it opens the door for the Euro High to vacate northwest, and for another, you otherwise have a huge wedge of tropical maritime air being pushed east where it can interact with the cold air to the north and initiate some cyclogenesis that has a good chance of taking place W or NW of the UK, much to our discontent. 

I have to say though, as much as the signals have long been for a difficult Atlantic versus HLB battle, recent GFS runs have just been taking the piddle, although having seen this behaviour to some extent even in the run-up to late Nov 2010, it's hardly surprising.

 

Currently, there are no consistent enough trends to make a call one way or the other with respect to the W. Atlantic trough. So it is that even with the immense HLB signal, no reliable trend toward significantly colder conditions in the UK can yet be interpreted.

[Man With Beard]

20 minutes ago, bluearmy said:

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

I think, as ever, the very best op run gets latched onto and anything else then becomes a downgrade. That's why I love these clusters because they simultaneously show what could potentially occur and give balance to the overall picture at the same time.

The reality is that the models, especially the ECM/GFS, have done brilliantly over the last week in consistently modelling an Arctic High extending towards our side of the pole with time. This is now showing between D6 and D10. 

The bit that's causing the trouble is the micro detail of how this affects the UK. Our shores are on the borderline of where this type of Arctic High will influence, so it's very much touch and go (though extremely possible) whether we go cold or not as a result. The last 4 ECM op runs at T240 have underlined this uncertainty beautifully, as they could not have been more different from each other. Indeed, the clusters for the 00Z run have just come out  - there are 4 clusters at T216 and I think each of the last four op runs are represented, more or less!!

interesting the option that Steve Murr has been promoting - the Scandi-Greenland linkup - appears as the 4th cluster (9 members out of 51)

BTW, in the D10-15 period, the trend is to fudge or collapse the HLB signal, except for the control run cluster (19 out of 51) which maintains good heights towards Greenland throughout.

 

 

[Ali1977]

So, here we are nearing winter again - and so far it's all looking quite positive for the coldies on here. With the NH PV looking weak let's hope some things fall in place for a late Nov freeze, prob a little early for anything decent over the next 2 weeks but after the last 3 years no one would grumble for a few frosts I'm sure . 

[Ali1977]

6 minutes ago, Ali1977 said:

So, here we are nearing winter again - and so far it's all looking quite positive for the coldies on here. With the NH PV looking weak let's hope some things fall in place for a late Nov freeze, prob a little early for anything decent over the next 2 weeks but after the last 3 years no one would grumble for a few frosts I'm sure . 

I'm living in Cyprus for the next few years so knowing my luck some cold winters will come, just need to time my UK visits with these !! Still, this is a great forum so will be keeping up to date with it daily I'm sure. 

[karlos1983]

2 minutes ago, Ali1977 said:

I'm living in Cyprus for the next few years so knowing my luck some cold winters will come, just need to time my UK visits with these !! Still, this is a great forum so will be keeping up to date with it daily I'm sure. 

You've probably got more chance than us judging by the past few years Ali  

[Geordiesnow]

Got to say, you do have to smile at how the Northerly flow for Saturday is looking more weaker as that stubborn shallow shortwave/weather front refuses to clear off in any great hurry so for southern areas instead of a chilly sunny day, it looks like its going to be a cloudy and not so cold feeling day with rain around. Sunday still looks on for a proper blast but it is short lived however Sunday night could well be quite a frosty one.

Mid range, at least for the weather for around our shores, it looks fairly unremarkable, there is a risk of perhaps a deep low heading towards us but details are very sketchy at this stage. Some have mentioned that those infamous D10 charts are not getting any closer but they are but details change every run, the well forecast split PV is coming closer now, pressure will be fairly high across the Arctic but  how that affects our weather remains to be seen. At this stage, on a cold perspective, those height rises will have minimal affect on our weather but this can quickly change. Really imo, I want too see the PV over the poles get a bit stronger again as this means perhaps the Arctic high can push southwards towards lower latitudes where an affect on our weather is more likely. Its one of those where I think model fatigue willl kick in though but hopefully it will be worth it in the end.

[knocker]

And they queue up to bring smiles to the faces of the Scottish chionophiles.

[MR EXTREMES]

1 hour ago, bluearmy said:

Reading posts wondering why the ‘good’ charts are always at day 10

maybe look at the NH output days 7-10 ??

how these aren’t seen as ‘good charts’ by coldies is beyond me 

Exactly blue no doubt in my mind the vortex is taking a right beating and I'd bet a bottom dollar a stratospheric warming event is likely this winter at some point.

Winter is not even here yet and I expect upgrades once blocking is situated over the poles.

It's clearly something the models agree on already a different feel to this autumn.

With a northerly on the way and a short northerly just recently.

I think the writing is on the wall tanked AO neg nao and southerly track jet low solar energy and low solar activity.

1963 I believe was also a Nina winter.

I certainly feel the way things are heading 09/10 is a possibility.

although 09/10 year was a el nino modoki yes,

but was an east qbo.

[Methuselah]

I'm minded to think that the model-outputs, when taken in their entirety, are pretty unanimous in their pointing towards a spell of significantly colder weather...What on earth could go wrong!

[Snowy Hibbo]

A look at the recent EC Monthly run.

14-20 Nov

Next week looks to feature two troughs, one over Iceland and the other centered over Southern Italy. A ridging pattern occurs in between those two troughs, including the UK. A fairly zonal jet occurs over the UK. Average temperatures across the UK, except for SE England, which is colder than normal. Drier than normal for England, wetter than normal for NW Scotland. Above average snowfall for the Scottish Highlands.

21-27 Nov

Then we start to get a troughing signal centered over France and Iberia. The trough extends over the southern parts of British Isles. A ridge looks to be over Greenland. The jet over the UK looks like it's heading towards the SE. Colder than normal for England, Wales and Ireland, average temps for Scotland. Drier than normal for Wales, the West Scottish Coast and much of Ireland, wetter than normal for the East Coast of Great Britain.

28 Nov - 4 Dec

We get a somewhat similar pattern to the previous week, with a trough signal over France, now heading over Southern Great Britain and across to Germany and Denmark. The Greenland High has moved somewhat to the SE, but is still present between Greenland and Iceland. This creates a ESE-SE direction jet across the U.K. Average temps for the entire UK. Drier than normal for Western Scotland and Ireland, average for the rest of the UK.

5-11 Dec

The only significant anomaly is the still present ridge in the North Atlantic, over Greenland in Week 2, now moving towards Iceland in Week 4. The ridging anomalies are now extending to the Northern UK. Average temps predicted for the U.K. Similar trend to the previous 2 weeks, with a dry Western Scotland, Wales and Ireland. Average precip for the rest of the British Isles. 

My European Seasonal Outlook should be out tomorrow. Cheers