Model Output Discussion 01/09/17

[Ice Day]

4 minutes ago, blizzard81 said:

I really feel that the models are struggling here. The ecm ensembles for debilt are very scattered. This won't be resolved for another 48 hours at least.

Indeed, this certainly won't be resolved on this run.  It's going from strange to downright bizarre with a monster low building off the west coast of Ireland

Edited November 13, 2017 by Ice Day

[tight isobar]

Madness!!

Everthing engages..

And evolves to a monster atlantic incoming storm type!!!

18z is surely going off its drunken nut here....!!!

[Man With Beard]

EC clusters at D8: demonstrates a three way split: a Euro high and mildish (22/51, a bit more than I'd thought), heights to NW with undercut (16) and a toppler (13).

[Zakos]

We are about to see a major pattern change,I wouldn't expect the models to perform very well until the block sets up.

Despite a very negative AO, the 18z laughably has the UK in a warm southerly flow.

However, the jet stream is weak and in disarray, aslong as a weak and disorganised polar vortex, a continuing trend in the output I believe.

Exciting times ahead

 

Edited November 13, 2017 by Zakos

[Snowy L]

Funny how as soon as the low pressure finds the best position to screw us over the shortwaves seem to disappear...

[Ice Day]

At this rate the low will completely span the Atlantic!!!!!

[tight isobar]

Gfs 18z evolves into a shocked mess..

Struggling on a large scale here dealing with the state in the pole-pv.

And simply 'cannot' find its feet..

Cannot take this run with any optional get out...

Again gfs finds hard work with blocking scenario's!!!

 

[booferking]

If the gfs is anywhere near right the country will be flooded before we see any snow lows just sit there pumping warm South westerlys and belt after belt of rain from 180hr to the end poor efford has to be said

[Frosty.]

Did I really say roll on the 18z..I meant the 00z

I'm off to look for those building blocks

Edited November 13, 2017 by Frosty.

[tight isobar]

Gfs 12z

 

Gfs 18z..

Either a complete turn of trend..or again the 18z is well of the mark!!!

 

[snowray]

Well done 18z, that makes it 3 horror shows out of 3 in a row. I wont bother posting any charts.

[mountain shadow]

The models are struggling because they are dealing with rare occurances.

I think Greenland heights are all but guaranteed, whether we can get low heights into Europe is the unknown at present.

[captaincroc]

We need to look at the early charts and see the trends in those as it's pointless to a degree looking any further at present. All the runs from all the models flip massively every run in the extended range as the just struggle with this rare pattern.  I am happy in the fact that the lows have a more southerly track early on, yes, not there yet but better than the 12z GFS. Baby steps. 

[snowray]

2 minutes ago, mountain shadow said:

The models are struggling because they are dealing with rare occurances.

I think Greenland heights are all but guaranteed, whether we can get low heights into Europe is the unknown at present.

Yes I agree that they are struggling but it just goes to show how unlucky we can be in the UK.

[swfc]

Altho the 18z fails to deliver to the uk the actual nhp even at the latter end isn't at all bad.weak pv and still ok for November. The fact is the models are struggling with a pattern change ie greenland high or west based blocking.o suspect it will be a different scenario tom .hopefully our friend to the sw will sling his hook south east towards the med.interesting if frustrating times but beats long fetch sw winds and rampant pv !!!

[booferking]

Don't worry we are still in the game after the op horror show a good few of the ens D8 keep us in the game for another day

Edited November 13, 2017 by booferking

[Ventnor Viking]

42 minutes ago, swfc said:

Altho the 18z fails to deliver to the uk the actual nhp even at the latter end isn't at all bad.weak pv and still ok for November. The fact is the models are struggling with a pattern change ie greenland high or west based blocking.o suspect it will be a different scenario tom .hopefully our friend to the sw will sling his hook south east towards the med.interesting if frustrating times but beats long fetch sw winds and rampant pv !!!

Just to add, the models don't factor in the extremely low solar output we are experiencing (and will continue to do with the occasional little spike) along with an eastern phased QBO which in my opinion both of these will have a significant affect on our pattern into mid December onwards. The general trend for the foreseeable future is to see the Arctics stratospheric 30 hPa and 10 hPa temperatures to decline to below average over the coming days. (sorry cant attach any links at the moment - will post later!) which will strengthen the jet temporarily due the temperature deviation from the arctic to that of the mid(ish) latitudes i.e. the northern Atlantic.   

Edited November 13, 2017 by Shaftesbury Snow

[A.J]

1 hour ago, nick sussex said:

Think of that shortwave running into the UK from T120hrs as the Millenium Falcon trying to escape the Death Star with secret plans to deliver some cold to the UK!

The Death Star tractor beam is that trail of energy to the Millenium Falcon. Once the MF can escape and detach itself it can deliver the plan.

That nose of high pressure just mentioned by SM is the tractor beam about to be disengaged. We need the shortwave to escape the tractor beam as early as possible run into the UK and then allow ridging to the north to exert pressure sw wards.

 

 lol

 

in reply to some unrelated posts (Not by you Nick!) earlier quoting ECM 10 mean charts .......isn't making a forecast call on such charts about as much good as boobs on fish or a chocolate fireguard?

[Geordiesnow]

The main trends which are developing is that a strong NE'ly flow will develop somewhere but also a west based nao has really gained strength with even the ECM coming on board on some previous GFS runs, the details are still prone to change mind so I still would not rule out something colder but it will be our luck if we end up on the mild side.

As I said last night, its one of those where a mild SW'ly is alot closer than one might think but being positive, if the models were showing a strong NE'ly at 144 hours ish, we would still be quite cautious and know it  will likely change so hopefully if there is any more changes, it will be one that favours cold weather.

[JBMWeatherForever]

Things still looking good overall for a prolonged period of cold from the northeast. I really think that all of the models will all be showing this very soon, with some classic north easterly scenarios. Usually once the block starts to become established the cold comes in much sooner than initially expected too. Role on next week.

[Cheshire Freeze]

If you could sum up the UK's luck with one synoptic chart, it would be this one

[Mucka]

UKMO and GFS not miles apart this morning, whether that is a good thing or not is another matter.

Still think UKMO has the slightly better upstream profile though.

[Mucka]

Looking through GFS ensembles there are still a good range of outcomes possible.

At around day 8 there are 4 runs which have us under cold polar air - all with a similar synoptic of Atlantic block and deep trough to the east bringing N/NE flow.

Let's hope they are onto something.

 

Edited November 14, 2017 by Mucka

[The PIT]

GFS continuing it's journey towards mild weather and unfortunately this is swinging into towards the reliable time frame. UKMO seems to be heading towards the same theme. After this weekend can't see much in the way of cold weather unfortunately.

[knocker]

A generally quiet day to day with England and Wales and N. Ireland under the influence of the HP to the south and Scotland the low pressure way to the north. With weak fronts hanging around the former tending to towards cloudy with the odd patch of drizzle in places perhaps becoming brighter later. Scotland brighter in a fairly gentle westerly with perhaps the odd shower.

Wednesday another quiet cloudy day for most but out to the west explosive deepening of the frontal low is taking place and by 12 Thursday it has raced NE between Scotland and Iceland to be 962mb east of Iceland by 12 on Thursday. This will bring strong winds and rain to N. Ireland and Scotland overnight Weds. as the associated front encroaches which then weakens as it tracks SE during Thursday.

During Friday the southern part of the UK remains under the influence of the HP thus quiet and dry whilst Scotland is under a strong showery north westerly But the situation is changing quite rapidly over the weekend as weak amplification of the HP to the SW takes place initiating a south east movement of the main low to the NE down into the Baltic states and a very transient ridge over the UK.  I say very transient advisedly as by Sunday lunchtime the next system from the west has split the ridge and has brought rain and quite strong winds to all and quite possibly snow on the leading edge of the front on the higher ground.

The low then tracks SE and the ridge attempts to reestablish itself but there is still a fair amount of energy emanating from the eastern seaboard upstream and the next trough arrives on the scene by midweek as the door to the Atlantic remains ajar. Best left here I feel

It was this sort of scenario that the anomalies were tending to indicate last night and this morning's GEFS is not disagreeing.

 

Edited November 14, 2017 by knocker