Model Output Discussion 01/09/17

[jvenge]

1 minute ago, karlos1983 said:

Can anyone here back this teasing tweet up? 

 

My source for the EPS 46 didn't update yet. But the last run showed some intermittent periods of colder shots (last Monday)

[bluearmy]

4 minutes ago, karlos1983 said:

Can anyone here back this teasing tweet up? 

 

The Monday night output was colder Than average but nothing notable 

next run due 10pm tonight 

[Iceaxecrampon]

00z

A week today somethings brewing for the rest of November - generally the run seems to be favouring a colder outlook also stonking output towards the end but prob cuckoo as per.

Apart from this weekend which should see the first decent falls over Cumbrian tops the ensembles dont seem that keen.

 

 

[Geordiesnow]

Longer term, the outlook has not changed of a split vortex but how that will affect our weather is still far to early to say so it be too premature to read into the details of what the models are saying at the moment. Some hints we may see parts of the PV dropping into Scandinavia eventually though which is always an encouraging sign.

Interesting times even if albeit the weather in the medium term for the UK does not look all that interesting with a general westerly flow dominating.

[SMU]

Wow meteociel being down is like the end of the internet!!!

anyway GFS 06z still churning out the most unusul of charts - at a time when the jet should be getting into full swing ! 

 Day 9

Edited November 9, 2017 by Steve Murr

[snowfall09]

 

[Man With Beard]

EC 00Z clusters - not as wintry as in recent days to be frank. 

Taking the D12 clusters chart,

the 1st cluster looks to have potential, but it contains the control run and those who've seen it know that it doesn't push through enough for cold to get to the UK. The 2nd cluster, looks like ridge/trough/ridge but doesn't look amplified enough to link up with the Arctic high and result in anything that cold. The 3rd cluster is not unlike the 1st, but still with the issue that heights will persist to the south and low pressure may get stuck over the UK.

I'm guessing the EC46 (which is based on this run) will still show anomalies for heights to our north but nothing significant enough to base a cold forecast upon.

It must be emphasised, though, that all clusters still provide the potential (arghhhhh!!!) for a colder outcome, even if it isn't obviously the favoured route.

However, this ensemble set does not fit in with the previous 10, and so a couple more runs are now needed to see if the downgrade of the Arctic/Greenland/N Atlantic heights link up is the new trend.

[knocker]

The gfs at 06 still throwing out the cyclogenesis with the 160kt jet only this time it does it twice. Worth a quick look at the three 12 charts Thurs > Sat even if they are a lot of whoo ha.

Edited November 9, 2017 by knocker

[Zakos]

Comparing the current state of the PV to the forecast from the ECM and GFS at 168+, it looks as if its going to become rather disorganised.

Taking mid november, as the start of the countrywide "snowhunt" I think we may well be off to a very good start this season.

Im no expert, but the below chart looks very blocked, reminiscent of november 2010...

We had a lot of teases from the models last year, but i dont recall seeing such epic charts as these in the near-reliable timeframe

 The consistency is notable, constantly we are seeing these very blocked patterns emerge in the output.Exciting times ahead I feel

 

 

 

 

Edited November 9, 2017 by Zakos

[SLEETY]

3 hours ago, snowbunting said:

The battle of the models begins. 

At time 240hrs

ECM going for high pressure.

The GFS going for a Nly lasting days

Both suggesting a greenie high building.

 

So which one will be right?

At that time frame.Both will be wrong.looking for trends is the only thing you can do when you get past about 5-6 days.

[Methuselah]

22 minutes ago, Steve Murr said:

Wow meteociel being down is like the end of the internet!!!

anyway GFS 06z still churning out the most unusul of charts - at a time when the jet should be getting into full swing ! 

 Day 9

I kinda like that chart, Steve...Not only does it scream potential, but guessing from how the building-blocks are aligned, we might even get a second bite of the cherry or, even better, a rinse-and-repeat...

I guess the obvious question is, however: will things be anything like that, once they become Day 1?

[Polar Maritime]

Yes Knocker the 6z shows not one but 2 lows crossing the UK around the 17th on a very strong Jet. Severe gales North & South..

Edited November 9, 2017 by Polar Maritime

[MP-R]

Even before then, it looks like there could be a brief period of strong winds in the south overnight this coming Friday into Saturday, tied in with that ex-Tropical system.

[Snowy Hibbo]

Firstly the blocking forecast

This is the EPS mean 10 day forecast across the Northern Hemisphere. You can see a clear trend of high latitude blocking,

developing in the D5 to D10 period. This correlates with a -AO. Troughing is also significantly present in the mid latitudes, further showing the -AO pattern across the Northern Hemisphere.

A similar pattern continues in the EPS mean to T+360....

The GEFS forecast for the AO reflects this trend, shown by EPS. Even though I am not lucky enough to have the WxBell EPS AO chart, it's safe to say both models are going for a -AO setup.

CFS also shows a -AO trend from now, into the ensemble's main forecasting period, and beyond that to around Mid December, when CFS thinks that the pattern will change to a more +AO setup, until late January. Very interesting to see a +AO like trend across most of winter, given most of the climate drivers are going for a -AO based winter.

 

Finally the various CFS forecasts for December in the past 6 days, in this freshly created chart from Ryan Maue.

It gives a great show at what are the trends and what are the distractions, in the various CFS modelling....

This is the CFS forecast for December averaged over the past 7 days (note 3 more runs added to the above chart).

It shows a mostly warm pattern for Europe, including the UK.

Anyway the seasonal models always for some reason seem to contradict the climate signals I see 

CFS apparently has a warm bias though....

 

 

[Polar Maritime]

3 minutes ago, MP-R said:

Even before then, it looks like there could be a brief period of strong winds in the south overnight this coming Friday into Saturday, tied in with that ex-Tropical system.

Yes MPR, Here's NetW-MR take on wind gusts for said time frame.

 

[carinthian]

UKMO picture at 144t, with almost same agreement with GFS and ECM .However by day 10 a big difference emerging between ECM and GFS. GFS showing a much more unsettled picture dominated by a big depression and ECM showing high pressure. Now the million dollar question, what does the UKMO computer show for the period development ( 144t -240t ) ?   Yesterday they were still indicating towards more settled quieter spell during this period. Interesting ! Will be interesting if I can try a get something out from our portal service provider regarding their various model interpretations later today.

 C

 

[Summer Sun]

2 minutes ago, carinthian said:

UKMO picture at 144t, with almost same agreement with GFS and ECM .However by day 10 a big difference emerging between ECM and GFS. GFS showing a much more unsettled picture dominated by a big depression and ECM showing high pressure. Now the million dollar question, what does the UKMO computer show for the period development ( 144t -240t ) ?   Yesterday they were still indicating towards more settled quieter spell during this period. Interesting ! Will be interesting if I can try a get something out from our portal service provider regarding their various model interpretations later today.

 C

 

At t168 UKMO extended keeps the low further west unlike GFS does just a shame these charts are not zoomed out further so we can see further north and east

[bluearmy]

Meteociel should be back for the 12z’s - power failure in Strasbourg apparently 

[SMU]

Meteociel is back..

06z is steady as she goes-

I will take PTB 10

Also when looking at the NH ECM day 10 its still looking good-

The landing zone for peak northern blocking is indicated to be 20th-23rd- & just because its not perhaps going to be insta cold from the 20th I would say we have a very big window appearing for cold in that 7-10 days...

S

 

 

 

[weirpig]

Extended  below  .  Shows  850s pretty much below zero all the way out.    Difficult really to judge were the blocking if any will setup  so not to helpful at this range.  Also towards the end one rogue run is heading towards the -10    Very good signs as we head into winter.   

[northwestsnow]

Delighted with the morning runs...plenty of blocky charts on offer and some cold frosty weather in the mix..moving forward meto still talking snow and below avg temps later in the month.

Edited November 9, 2017 by northwestsnow

[BlueHedgehog074]

Before the possibility of some blocked conditions later in the month (some of which may produce some heavenly treats for the snow weather enthusiasts) the GFS surprisingly continues to upgrade the Northerly flow for this Sunday. Didn’t look at the 00Z run, but the 06Z now has the -5*C 850 hpa temperature line covering the whole of the U.K. (except for far South-West of Ireland). Some of the previous runs showed patchy areas of the -5*C isotherm covering the U.K., so a slight improvement for upper cold. I think what helps is the Atlantic ridge looks a touch more amplified, which I think is helping to drain some colder 850 hpa temperatures further South from the Arctic, along with a slightly better Northerly flow. Showers could be wintry anywhere (albeit most of them concentrated over Northern UK and down the coasts), but still with the best chances of settling snow on top of hills, especially to the North

Outside of (wintry) showers, it would be bright and sunny. Would make for some great walking in the chilly, crispy, conditions! 

(Clearly, as some others said, there is a chance of some windy and wet conditions to contend to before Sunday’s Northerly!)

[bluearmy]

4 hours ago, karlos1983 said:

Can anyone here back this teasing tweet up? Are we destined to go cold even if it’s a longer route to get there like the picture ECM is painting this morning?

 

note the 00z eps suite is far less convincing on the scale of the neg AO and its duration. Perhaps best to see what the 12z brings

Edited November 9, 2017 by bluearmy

[Paul_1978]

Latest AO forecast has just come out....... Attached yesterday's and today's.

If that's still not going down I don't know what is.

Edited November 9, 2017 by Paul_1978
Corrected attachments

[karlos1983]

13 minutes ago, Paul_1978 said:

Latest AO forecast has just come out....... Attached yesterday's and today's.

If that's still not going down I don't know what is.

I think there’s little question of the AO going negative, it’s whether the NAO is negative and if it’s positioned favourably for us or west based 

Currently looks like we can tick one of them off...... it seems to be going negative, but where !?!

Edited November 9, 2017 by karlos1983
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