Model Output Discussion - Snow for some, but what else is in store?

[cheshire snow]

Short term as per warnings heavy rain will be the main headline maker Thursday looks a wintry day according to the 06GFS with snow Manchester Northwards with possible blizzard conditions over Scotland.

C.S

[syed2878]

19 minutes ago, Vikos said:

Don't search in determistic outputs. See the background signals. Those look promising

And first of all: Don't lose hope, keep the faith. This applies to alot these days, in GB as in GER and the rest of the continent

Sometimes there are things on earth more important then snow in the backyard...

sadly those back ground signal supposed to be good since winter 2019 however so far they have failed to deliver so forgive me if I don’t put all my eggs in the background signals.

[sebastiaan1973]

19 minutes ago, MKN said:

gfs would be better off only going out to +240. Even that is deep fi atm

 I doubt if this is true. The models show consistent the same thing. With of course some variation. The plume (won't show it) is day after day te same. So, instead of uncertainty, it's quite certain what happens in the next ten days in general terms.

[sebastiaan1973]

2 minutes ago, syed2878 said:

sadly those back ground signal supposed to be good since winter 2019 however so far they have failed to deliver so forgive me if I don’t put all my eggs in the background signals.

In winter 2020 there were no good backgroundsignals due to the extreme positive IOD.

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RMETS.ONLINELIBRARY.WILEY.COM

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Northern Europe and the UK experienced an exceptionally warm and wet winter in 2019/20, driven by an anomalously positive North Atlantic Oscillation (NAO). This positive NAO was well forecast by several seasonal forecast systems, suggesting that this winter the NAO was highly predictable at seasonal lead times. A very strong positive Indian Ocean dipole (IOD) event was also observed at the start of winter. Here we use composite analysis and model experiments, to show that the IOD was a key driver of the observed positive NAO. Using model experiments that perturb the Indian Ocean initial conditions, two teleconnection pathways of the IOD to the north Atlantic emerge: a tropospheric teleconnection pathway via a Rossby wave train travelling from the Indian Ocean over the Pacific and Atlantic, and a stratospheric teleconnection pathway via the Aleutian region and the stratospheric polar vortex. These pathways are similar to those for the El Niño Southern Oscillation link to the north Atlantic which are already well documented. The anomalies in the north Atlantic jet stream location and strength, and the associated precipitation anomalies over the UK and northern Europe, as simulated by the model IOD experiments, show remarkable agreement with those forecast and observed.

[MJB]

26 minutes ago, MKN said:

Posting +384 charts is completely pointless. They will never verify particularly during winter. gfs would be better off only going out to +240. Even that is deep fi atm

And how often does 240 verify , this is a discussion that's been had for years , its a Model Output Thread so all time frames can be discussed surely?

[Vikos]

1 minute ago, syed2878 said:

sadly those back ground signal supposed to be good since winter 2019 however so far they have failed to deliver so forgive me if I don’t put all my eggs in the background signals.

Sorry, dude, but this isn't the moan thread. Synoptics is the prediction of an outcome, not the hope for an special outcome. That's the game! If hope on a certain weather pattern is your goal, than mid-to-long-term synoptics is maybe the wrong hobby to do.

For me, every thrilling synoptic outlook is favourable. Let it be heavy rain, strong storms in autum, snowfalls, winter thunderstorms or even blizzards, heat waves in summer and their dramatic ends with huge MSC systems. As long as it isn't boring for ages I am fine with any weather pattern.

[syed2878]

9 minutes ago, sebastiaan1973 said:

 I doubt if this is true. The models show consistent the same thing. With of course some variation. The plume (won't show it) is day after day te same. So, instead of uncertainty, it's quite certain what happens in the next ten days in general terms.

 

Edited January 18, 2021 by Paul

[Methuselah]

Well, if this morning's 06Z is right, it's looking ever more likely, that we've missed our chance of any deep, meaningful cold . . . at least for now?

    

 

[Frigid]

Impressive heights showing up on the 6Z. Lots of northern blocking about, just need them iberian heights to budge

[KTtom]

2 hours ago, KTtom said:

I make it 8 if you want to split hairs  Prior to that its dry after this weeks deluge (check feb1991blizzard post).

Sad times when you quote yourself  But to add to this mornings ECM, GFS also, just at day 7, absolutely no sign of lows tracking south...someone has this spectacularly wrong because models seem to be in a bit of agreement in this set-up. 

[mushymanrob]

6 minutes ago, General Cluster said:

Well, if this morning's 06Z is right, it's looking ever more likely, that we've missed our chance of any deep, meaningful cold . . . at least for now?

    

 

Theres loads of deep meaningful cold on those charts.... unlike most years.... its just locked up just north of us.

[frosty ground]

Just now, KTtom said:

Sad times when you quote yourself  But to add to this mornings ECM, GFS also, just at day 7, absolutely no sign of lows tracking south...someone has this spectacularly wrong because models seem to be in a bit of agreement in this set-up. 

You ignored the GFS 0z Run thou, and it will no doubt change again by the 12z.

[cheshire snow]

just incase of any interest curtious of the 06GFS

C.S

[MJB]

1 minute ago, KTtom said:

Sad times when you quote yourself  But to add to this mornings ECM, GFS also, just at day 7, absolutely no sign of lows tracking south...someone has this spectacularly wrong because models seem to be in a bit of agreement in this set-up. 

Isn't that one over the IOW ?

[IDO]

4 minutes ago, cheshire snow said:

just incase of any interest curtious of the 06GFS

C.S

Def need elevation south of the wall, but prospects for Scotland and places with hills and mountains should see some action and I suspect a warning will come:

[stratty]

The Control has this for Saturday

 

,,,,,and then Sunday  

Edited January 18, 2021 by stratty

[KTtom]

20 minutes ago, MJB said:

Isn't that one over the IOW ?

If you follow the thread, were talking about next week. Im not saying it wont change back again, and i havent disscounted the 00z either, but this is more current. Its not moaning its what the most recent model runs show!

Edited January 18, 2021 by KTtom

[nick sussex]

Good agreement on the overall pattern but detail wise still a lot of uncertainty on the smaller features .

Initially the low deepens over the UK , this begins to fill slowly after that shortwave runners ejected by the upstream troughing in terms of track will change between runs and so snow chances although marginal for most will equally change .

The situation becomes even more complex towards day 8 . At this point the upstream troughing starts moving east and you can see here on the GFS06 hrs run less trough disruption and a phasing with the shortwave low to the north .

The earlier run didn’t do that and had that nose of better heights between that and the upstream troughing .

This really is a battle between the Azores high trying to ridge north in response to the upstream troughing and the forcing exhibited by those Arctic heights .

The battle lines sit over the UK. 

The morning ECM run was a mild outlier for day 7 into 8 so some scope there for that shortwave shown there  to run further south .

Overall it’s a very messy picture upto day 8 but not without some snow potential more especially for northern areas . 

After that more upstream trough disruption and no phasing issues with shortwave energy over the UK likely to keep most in some colder conditions , on the other hand a repeat of this mornings GFS 06 hrs run is an equally plausible solution.

As ever more runs are needed !

[sebastiaan1973]

Anyone intrested in spring? GFS6h. Para on the very long term shows an interesting setting with a cold Scandinavia.

 

Edited January 18, 2021 by sebastiaan1973

[Jason M]

13 minutes ago, mushymanrob said:

There's loads of deep meaningful cold on those charts.... unlike most years.... its just locked up just north of us.

Whilst true it doesn't matter for us unfortunately because the models are increasingly bullish on high pressure over Spain and for the southern half of the UK its pretty much game over once that becomes established. Ultimately this will change our cold rain to warm rain!

Entropy seems quite low at the moment as well. When I looked through the day 10 GEFS earlier 29 of the 30 had the Iberian heights as a key feature. Given that it also tends to run with our usual climatology it becomes a hard signal to ignore. When I refer to entropy I'm looking more at the big picture in our part of the world because detail within the envelope of possibilities changes all the time. 

Its been a winter of pretty looking (albeit not very cold) charts at day ten but in reality at no stage has a significant cold spell ever been likely and that remains the case.

Interesting though how within days of the SSW occurring the output has settled quickly. The SSW has the reputation of introducing chaos but oddly this one seems to have had the opposite impact with most of the output agreeing on the overall pattern. I'm sure others will disagree on this which is fine, but for me we are looking south now rather than north as for the UK everything hinges on getting rid of those heights over Spain.

[I remember Atlantic 252]

29 minutes ago, stratty said:

The Control has this for Saturday

 

,,,,,and then Sunday  

Would be amazing, but think control has Saturdays slider too far north, most of these move south and end up in France

[Methuselah]

Day 10, and nary a sign of our seeing and deep, meaningful cold, any time soon . . . maybe time to add 'nailed on' to the swear filter?

    

 

Edited January 18, 2021 by General Cluster

[sebastiaan1973]

Unfortunately- the average is of GFS6u 240H ain't better (won't show this)

15 minutes ago, Jason M said:

Interesting though how within days of the SSW occurring the output has settled quickly. The SSW has the reputation of introducing chaos but oddly this one seems to have had the opposite impact with most of the output agreeing on the overall pattern. I'm sure others will disagree on this which is fine, but for me we are looking south now rather than north as for the UK everything hinges on getting rid of those heights over Spain.

This was quite soon clear, the vortex of this SSW displacement was placed in the Atlantic Ocean. In this case, chaos was limited. Further on, I suppose the models are quite good nowadays in dealing with the SSW.

Edited January 18, 2021 by sebastiaan1973

[mushymanrob]

9 minutes ago, Jason M said:

 

Its been a winter of pretty looking (albeit not very cold) charts at day ten but in reality at no stage has a significant cold spell ever been likely and that remains the case.

 

I disagree with that line though... it has been so far a frustrating year as the potential is and has been great. We have been on the brink for a month now, but the final peice of the jigsaw has so far eluded us.
And according to the hadley centres CET, this january so far has been the second coldest since 1987 ..

But so far we are the Lena Valatis of winters, She came second 40 years ago in the Eurovision Song Contest... Behind Bucks Fizz... we all remember the winner but not the runner up.
 

[MATTWOLVES 3]

4 hours ago, carinthian said:

I would say thats a wintry chart Thursday going into Friday. Snow chances increasing further south into the British Isles based on latest UKMO output.

 C

I'm so glad you post @carinthian especially being that your so far out of the UK,yet you bring us some great updates from yourself and the team over there in a very level headed way. Your correct in pointing out we could be looking at some wintry action the backend of this week,and not to forget we have a fair amount of action these next few days also..Yet all im seeing on here is arguments over 10+ day output again,and how the SSW failed us...well there is still a secondary warming that took place last week to consider yet! Everyday we seem to see the 6Z suites go downhill before improving come the 12s...is it really worth the stress and arguments,when its clear as night and day...the models are struggling!

Just to add Matt H picked up on something more significant from GFS regarding a more meaningful split of the Vortex towards the end of its run...Now if that comes off,a very interesting later Winter period also. In the short-term lots of action to keep you going.

Edited January 18, 2021 by MATTWOLVES