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

[TEITS]

6 minutes ago, Ice Day said:

Welcome back TEITS, we all have our bad days!!!

The bit in bold is the big point at the moment, there is clearly a transition going on which the models are not yet getting a proper handle on, but we COULD end up with with something notable that is not even been shown at 168.  A few hints starting to turn up but I reckon by tomorrows 12z's we'll start to get a good idea where the next 7-14 days is heading.  Maybe we will throw a double 6 for once?

Thanks.

Personally the UKMO is the model to follow and I shall use this weeks modelling as an example.

This is what I said 6 days ago.

"if I put my unbiased hat on then in my opinion none of the models are correct. I feel the GFS is too quick in bringing a return to milder W,lys. The high pressure building on the ECM bringing the E,lys is more likely to be further S bringing E,lys to the Med rather than the UK."

https://www.netweather.tv/forum/topic/86906-model-output-discussion-29th-december-into-mid-winter/?page=146#comment-3511135

For many years now the UKMO always seems to model the area between Greenland/Iceland/Scandinavia/UK much better with regards to blocking than the other models. The ECM always shows OTT blocking whereas the GFS is frankly very poor and needs about 8 runs to adjust to the correct solution. So the trick in finding the right outcome is to factor in the bias of these models which is due to how they are programmed.

[ArHu3]

6 minutes ago, TEITS said:

Thanks.

Personally the UKMO is the model to follow and I shall use this weeks modelling as an example.

This is what I said 6 days ago.

"if I put my unbiased hat on then in my opinion none of the models are correct. I feel the GFS is too quick in bringing a return to milder W,lys. The high pressure building on the ECM bringing the E,lys is more likely to be further S bringing E,lys to the Med rather than the UK."

https://www.netweather.tv/forum/topic/86906-model-output-discussion-29th-december-into-mid-winter/?page=146#comment-3511135

For many years now the UKMO always seems to model the area between Greenland/Iceland/Scandinavia/UK much better with regards to blocking than the other models. The ECM always shows OTT blocking whereas the GFS is frankly very poor and needs about 8 runs to adjust to the correct solution. So the trick in finding the right outcome is to factor in the bias of these models which is due to how they are programmed.

the surprise winner for europe (not the n hemisphere as a whole though) this winter in the 7-10 days range, according to ecmwf even was gem though

 

http://apps.ecmwf.int/wmolcdnv/scores/mean/500_z/score=rmsef|domain_name=europe|vstream=wmo_ob|running_mean_window=1|date=201612|

Edited January 14, 2017 by ArHu3

[booferking]

1 minute ago, TEITS said:

Thanks.

Personally the UKMO is the model to follow and I shall use this weeks modelling as an example.

This is what I said 6 days ago.

"if I put my unbiased hat on then in my opinion none of the models are correct. I feel the GFS is too quick in bringing a return to milder W,lys. The high pressure building on the ECM bringing the E,lys is more likely to be further S bringing E,lys to the Med rather than the UK."

https://www.netweather.tv/forum/topic/86906-model-output-discussion-29th-december-into-mid-winter/?page=146#comment-3511135

For many years now the UKMO always seems to model the area between Greenland/Iceland/Scandinavia/UK much better with regards to blocking than the other models. The ECM always shows OTT blocking whereas the GFS is frankly very poor and needs about 8 runs to adjust to the correct solution. So the trick in finding the right outcome is to factor in the bias of these models which is due to how they are programmed.

Yep the UK model has been very good its been trumping the rest of them one to follow.

[Summer Sun]

High pressure will stay most of next week if UKMO is right if that high continues to move east then we could see come northerly winds during the final full week of Jan

Either way after Monday we shouldn't see much in the way of rain

[The Weather Dragon]

We should have a UK met model only thread with no comments from other models allowed lol 

[Timmytour]

T90..... low pressure to west of Iceland behaving differently on this run...

6z v 0z
 

[Ali1977]

At 174 if I didn't know better I'd say this is a great chart , so hard to get the goods to our shores.

[Day 10]

Another different solution on the way

[Day 10]

Bitterly cold for Southern Ireland

[West is Best]

46 minutes ago, TEITS said:

Thanks.

Personally the UKMO is the model to follow and I shall use this weeks modelling as an example.

This is what I said 6 days ago.

"if I put my unbiased hat on then in my opinion none of the models are correct. I feel the GFS is too quick in bringing a return to milder W,lys. The high pressure building on the ECM bringing the E,lys is more likely to be further S bringing E,lys to the Med rather than the UK."

https://www.netweather.tv/forum/topic/86906-model-output-discussion-29th-december-into-mid-winter/?page=146#comment-3511135

For many years now the UKMO always seems to model the area between Greenland/Iceland/Scandinavia/UK much better with regards to blocking than the other models. The ECM always shows OTT blocking whereas the GFS is frankly very poor and needs about 8 runs to adjust to the correct solution. So the trick in finding the right outcome is to factor in the bias of these models which is due to how they are programmed.

Great to see you TEITS my old friend, though I'm a tad different now

I think you're absolutely spot on about UKMO. It has become the gold standard model in my opinion. Of course, it does help that it only runs to T144 on the extended.

[booferking]

Another close but no cigar outcome on the 06z chase for the Northerly-North Easterly just falls short we might get there next run finely balanced.

[karyo]

2 minutes ago, booferking said:

Another close but no cigar outcome on the 06z chase for the Northerly-North Easterly just falls short we might get there next run finely balanced.

The Atlantic low is not doing us any favours.

[Scandinavian High.]

On verge of being plunged into a north easterly ..

[stodge]

Morning all

I confess I've no idea where we are going after the end of the coming week.

The Atlantic is still quiet but seems to try to crawl back in - a number of runs have tried to send the PV back to Greenland after it gets to Siberia during this week. I note incidentally Mr Murr's comments on the near SSW on the Eurasian side. As we know, these tend to send the PV back to Greenland so a cautionary note for those wishing for an SSW.

Looking at the GFS 06Z OP I see a whole lot of nothing going on (as the song has it) after the PV relocation. Without the energy to fire the Atlantic, it's all very slow and doubtful so I suspect we'll see plenty of possible evolutions beyond T+240.

I do think a period of milder zonal conditions is unfortunately now the form horse going into the end of the month though how far south the jet will be is to be resolved.

 

[Froze were the Days]

It's the same old problem at 204z on the GFS we need heights to get out from the azores region, if we had lower heights there it really would be game on - this seems to be a recurring problem particularly with Atlantic high pressure amplification, either that or lobes of shortwaves near Greenland.

By the way I bet this run ends on a mild Atlantic basis.

By the way thought the ECM 0z looked quite good with a southerly tracking jet, only the last 240z frame looked disappointing with LP refusing to slide.

Edited January 14, 2017 by Froze were the Days

[The Weather Dragon]

Interesting period late next week - lots to be resolved. General cross model consensus is for build of pressure to NW/Iceland - could give us a decent spell. Top tip - - look to UK MET

[TEITS]

21 minutes ago, West is Best said:

Great to see you TEITS my old friend, though I'm a tad different now

I think you're absolutely spot on about UKMO. It has become the gold standard model in my opinion. Of course, it does help that it only runs to T144 on the extended.

Cheers matey.

A stress free winter of following the models is always to stick with the UKMO and don't look at anything else. Problem is I just cannot stop myself.

[Rocheydub]

43 minutes ago, TEITS said:

Cheers matey.

A stress free winter of following the models is always to stick with the UKMO and don't look at anything else. Problem is I just cannot stop myself.

Like the rest of us,and sure isn't it what makes model viewing so intriguing! I felt like having a blast on here loads of times, so I understand. Welcome back TEITS, this ol place just wasn't the same without you!

[Guest]

3 hours ago, TEITS said:

Absolutely right.

The model output is far too interesting to stay away plus I acted like an idiot the other day. Apologies everyone.

Lets compare todays 0Z ECM with yesterday mornings.

Considering the differences are we really going to be worried about what the ensembles say.

What makes next weekend into the following week so exciting is the uncertainity. We could have very mild SW,lys or bitterly cold NE,lys. We could even have the situation where S England is bathed in mild temps whereas N England is experiencing blizzards. The fact is we just do not know yet!

 

 

I really admire anyone who makes a sincere apology and you are right about painting a more positive spin on the outlook. The models are still flip flopping in the very short term and may continue to do so in this "Winter of Wild Cards". There is a huge reservoir of cold over most of Europe. I will focus on this in my weekly full report tomorrow evening. Right now the models are at an interesting stage. I prefer a cross model comparison. Let's have a quick look at the "big 6" (+GEFS mean ensemble charts) for 0100 on Tuesday, January 17th, just 3 days out. I've taken account of the forecast timings to ensure an exact comparison: 

                     GFS 6z T+ 66                                             UKMO 0z T+72                                       ECM 0z T+72                                            GEM 0z T+72

    

                    JMA 6z T+66                                     NAVGEM   0z T+72                                    GEFS ensemble 6z T+66

     

So, strong consistency, which is hardly surprising for D3 charts. They all show the HP over the UK with slight ridging to the north-east and low heights over the central Mediterranean. I feel that this is the first critical period in terms of an attempted transition to a continental feed. Now, let's do the same for the D6 charts for 0100 on Friday, January 20th:

                  GFS 6z T+138                                             UKMO 0z T+144                                       ECM 0z T+144                                      GEM 0z T+144

   

           JMA 12z (yesterday) T+156                            NAVGEM 0z T+144                               GEFS ensemble 6z T+138

  

Considering all the inconsistency until a few days ago, the D6 charts are still remarkably similar. They all show high pressure more or less sitting over us. Most of them show the HP ridging westwards and north-westwards, several up to Greenland. I've followed the relative merits of having a west based -NAO which all the models point towards at D6 but I do not believe that this is really relevant. To me, we are still in the middle of the transition period and we are simply riddled with possibilities! Okay, a strong cold easterly is not quite showing but there is no sign of a zonal Atlantic flow. I feel that D6/D7 is FI right now as the models really start to explore the different options for week 2. So, despite a couple of less cold days (mildest in the west and north-west), the next week looks generally on the cold side (except perhaps the far north-west) and possibly some cold to very cold surface conditions developing and spreading up from the south-east. This largely continues into next weekend. No bitter easterly yet and no snow, unless we see some on the milder/colder divide over the next couple of days. The longer this blocked pattern continues the greater the chance of pulling in either a progressively colder easterly (which could be dry OR quite snowy) or another northerly (perhaps more protracted next time). We might see an alternation between the two. There might also be some very brief milder interludes. Then we have all this talk of a stratospheric warming event which usually but not always favours a colder pattern for the UK. I will develop some of these themes in my report tomorrow but in the meantime, the message is a positive one for coldies (and perhaps later on for snowies) with plenty to keep us interested during the next few days and coming weeks. This Winter is a highly unusual one and is very, very far from over.

EDIT:  I like NetWeather's new "current  weather map" with all the different features and station readings. Perhaps several maps are a little crowded and somewhat confusing but I'm sure these things can be improved upon as the process evolves. One special request - would it be possible to have an updated pressure chart? The old MetO site used to do this but dropped it last year. It would be so useful for monitoring developing situations such as the forthcoming encroachment of the milder air with the fronts possibly stalling over the east and south-east. For those who followed last night's storm surge, it would have added so much more if we could have seen the changing depth of pressure and the track of that offending North Sea low pressure. With these "nowcast" tools it will create a bigger following and a separate thread could be used for comments and the exchange of views.

@johnholmes re: your post just below this one - I like that chart you link to and the options available and I haven't seen it before.

Edited January 14, 2017 by Guest
Correct typos

[bluearmy]

If you only look at UKMO then you aren't much better off than reading the met office web page

infact, unless there is something notable in the immediate offing, you aren't going to spend any time in here. 

You could make an arguement for not looking at op runs post day 6. 

The ens will always be the cause of disagreements and no one is likely to be swayed from their position

fwiw, the 06z gefs return the e Canadian segment courtesy of a mean Alaskan ridge  which had been well advertised

there is some amplification for the n Atlantic and the fi euro heights are less marked than previous output with the upper trough headed closer to our shores 

[The PIT]

Nothing really to get excited about now with the demise of the easterly. Normal FI teasing of a cold spell. The only good trend from the models is that the Atlantic is going into a quiet phase which may allow another idea to pop up nearer the reliable time frame that might actually verify.

[johnholmes]

Browsing the web and came across this

http://www.ecmwf.int/en/forecasts/charts/medium/mean-sea-level-pressure-wind-speed-850-hpa-and-geopotential-500-hpa?time=2017011400,168,2017012100¶meter=Wind 850 and mslp&area=Europe

never seen it before, does anyone use it?

[SMU]

14 hours ago, Steve Murr said:

Evening All -

Im signing off from the MOD for a while as I think for now ive had enough of looking the models only to be let down at the last minute-

final scores on the doors for this recent period-

ECM 9 This model has been great all the way from day 10 when it had the Scandi ridge - the precision & accuracy has been top notch, sadly though the 'global' & indeed regional inaccuracy at day 6/7/8 has been the achilies heel for the UK being that day 4 & 5 ( from 6 & 7 ) have adjusted painfully about 300 miles south- nothing in the grand scheme of things but enough to change the surface temps in england & debilt upwards by about 4 degrees so what was once modelled at 0c daytime maxima & that 'perfect' continental winters cold is now just chilly 4/5c modified air...

 

GFS - 6

The  GFS never really bought into the Easterly at day 6,7,8 & had to be dragged back to the amplified pattern after being Way way to flat - once it got the longwave pattern correct about day 6 its been 'ok' ish but volatile

 

UKMO -9

This is the UKMETS winter- it was onboard amplification right from 168 however was always a toned down ECM & not 1 run had a decent easterly showing, even when GFS & ECM alligned for a day - the UKMO wasnt interested - well done!

 

Moving foward there is still ( Day 7-9) there is still a whiff of a continental flow perculating around the models - which sends the temps back down to 1-2c maxima - however I will put that on the back burner for now - I think we have a fair shot @ the retrograde getting far enough west to keep it cold to day 10 & within that as said enough scope to pull a gentle easterly- ( like feb 86 )

 

I guess the big perhaps HUGE news today is that the SSW forecast thats manifested in my zonal means charts over the next few days - I cant remember who I said to to watch the models it may have been @feb1991blizzard however the forecast is as follows -

SSW over Russia to hit the pole around 19th-23rd of Jan - The zonal wind at that time is expected to be around 40 M/S westerly which is a tad above normal - The deceleration curve of the 10HPA 60N zonal wind post warming is approx 8 M/S per day-

Therefor my forecast would be an official classification of a SSW ( zonal wind reversal @ 60N 10HPA ) for the last couple of days of Jan- or if its a double dip SSW where theres a big drop in winds before the final drop into negative the landing zone will be around Feb 1-4

The initial & very early assessment is that its a wave 1 induced warming not wave 2 this is because this is likely to be a vortex displacement not a vortex split- 

10HPA

likely blocking pattern is Greenland slightly west based with low scandi heights -

UK windflow therefor Northerly/ North westerly- poss NE if we are lucky.

There could be an immediate troposheric response circa very late Jan however the usual lagged response is more likely 7-10 days so early doors feb week 1 / week 2-

-EPO ridge & Greenland block is favoured-

until then unless we scrape deeper cold sooner or the retrograde at the end of the week is better im signing off MOD until the SSW comes to fruition...

Remember the dates SSW end of Jan....

S

 

 

 

Morning-

The forecasted SSW gathers pace today

deeper negatives  - along a similar glidepath timewise...

100% ensemble agreement

CIAO

Edited January 14, 2017 by Steve Murr

[booferking]

12 minutes ago, Steve Murr said:

Morning-

The forecasted SSW gathers pace today

deeper negatives  - along a similar glidepath timewise...

100% ensemble agreement

CIAO

Hey steve whats the Ave lag time follow a SSW to see the effects on models? Sorry edit that just seen you said 7-10 days after the ssw but maybe the possibilty to see it end of Jan. Cheers

Edited January 14, 2017 by booferking

[Ali1977]

6 minutes ago, booferking said:

Hey steve whats the Ave lag time follow a SSW to see the effects on models?

Was thinking the same thing, some say 2 weeks some say 4 or more!! Does this depend on SSW strength or positioning or something different . What I do like is that this SSW; if it happens isn't too late on, so if we can Benefit from it it should be when we still have low sun etc...

Edited January 14, 2017 by Ali1977