Model output discussion - into Christmas

[snowray]

43 minutes ago, feb1991blizzard said:

The GFS 18z follows this so not sure where met office forecast of very mild for first half of jan is coming from.

They have all been out drinking, still dreaming of Euro highs I guess. We are ahead of the curve on here!

Anyway, who's staying up for the first runs of the year and the decade then??????

We are expecting some mega model watching in 2020!

[North-Easterly Blast]

Great to see just for fun are those charts - but unless more members go for that setup and they all get into the reliable timeframe, looking at them for fun is all they are sadly.

[snowray]

11 minutes ago, North-Easterly Blast said:

Great to see just for fun are those charts - but unless more members go for that setup and they all get into the reliable timeframe, looking at them for fun is all they are sadly.

Yes sadly the mild ENS are the ones that almost always verify, we are well and truly conditioned to this fact. But as my old dear uncle used to say, things can go wrong a hundred times but then just once you get lucky.

[syed2878]

well folks models are quite horrific at the moment anyway to all NW members and staff are very happy and a prosperous 2020 hope all of you will have a good year and for those of you who had a difficult 2019 I hope and wish you all a peaceful and a happy 2020.

[Ali1977]

Happy New Year to you all.

New Year, new prospect of cold? Sadly not, but the long term GEFS mean is hinting at a pressure rise to our East in FI, and a few take the heights up into the North or Scandy. Lets see how that plays out !! 
 

The severe Winter of 1947 started on Jan 23rd, something like that will do

Edited January 1, 2020 by Ali1977

[IDO]

Looking at the D8-D16 GFS op and nothing good there, in fact the de facto Winter spoilers and as bad as it gets for eating the winter away:

The tPV in the worse place possible, the omnipresent Russian High that this winter has been of no help. A Pacific high that oscillates sending wedges into higher lats on the wrong side of the NH, keeping the tPV locked into the absolute worse place for height rises in Greenland or Scandi. Watch those HP cells generated from the Pacific keep the upstream flat, enabling the westerly zonal washout.

It is hard to imagine a flip from here given the lack of a cohesive MJO signal, no tropical forcing and the strat unlikely to help in the medium term? It certainly looks like we have to look for Feb/March for anything wintry. Here's hoping!

Happy New Year to all.

Edited January 1, 2020 by IDO

[nick sussex]

Happy New Year to all .

The models though lack much festive cheer .

The GFS op is ghastly for cold with a tightly coiled PV . The ECM though towards day ten is not terrible , we are dealing with least worst so compared to the GFS horror show for coldies the former at least disrupts the PV and tries to drop a trough south into Scandi .

Whether that lasts till tonight is another matter !

I think being realistic we need to write off the first half of January and just accept it’s not going to happen for anything remotely interesting in terms of cold and snow .

As for the second half of the month we need to see whether there’s any mileage in the PV disrupting as shown by the ECM , and even if that does happen how long that lasts for .

[Man With Beard]

8 hours ago, blizzard81 said:

Thanks for the info. I noticed debilt went cold later on. I guess the control run was one of the scandi highs? 

Yes it was

[Nick F]

1 hour ago, IDO said:

The tPV in the worse place possible, the omnipresent Russian High that this winter has been of no help. A Pacific high that oscillates sending wedges into higher lats on the wrong side of the NH, keeping the tPV locked into the absolute worse place for height rises in Greenland or Scandi. Watch those HP cells generated from the Pacific keep the upstream flat, enabling the westerly zonal washout.

Happy New Year all!

The best we can salvage from the strong westerly onslaught, as the strong jet and low heights of the PV over Greenland shunt increasingly south over the Atlantic is some cold zonality. GFS ops been advertising this over recent runs, albeit in the medium range - which it has a well-known cold bias in that timeframe. If UK can get north of the jet, as T+198 shows below, then we may at least get some snow potential for the north, particularly hills. But, we need to get the jet south and also wary of the GFS op cold bias.

Otherwise little in the way of crumbs of comfort for snow lovers for now.

Edited January 1, 2020 by Nick F

[bluearmy]

1 hour ago, Man With Beard said:

Yes it was

And is again ......it’s all the coldies have to hang their hats on mid month onwards .........mid Atlantic trough extension from tpv  and downstream sceuro ridge is the broad pattern and within that, a scandi ridge could happily sit ....... but the polar profile would have to play ball to help amplification  ......

Edited January 1, 2020 by bluearmy

[North-Easterly Blast]

Another day and the first day of January and the New Year, with still nothing in the models suggesting any pattern that could bring a significant cold spell to the UK.  If close to solar minimum and with a neutral ENSO we cannot salvage something out of this winter in terms of a significant cold spell in the UK, then it is hard to believe we ever can again.  I know that in winters 2013-14 to 2016-17 background signals were less favourable for patterns to develop that can bring cold to the UK, but if low solar activity and neutral ENSO cannot deliver something then what can?

[Weather-history]

6 minutes ago, North-Easterly Blast said:

Another day and the first day of January and the New Year, with still nothing in the models suggesting any pattern that could bring a significant cold spell to the UK.  If close to solar minimum and with a neutral ENSO we cannot salvage something out of this winter in terms of a significant cold spell in the UK, then it is hard to believe we ever can again.  I know that in winters 2013-14 to 2016-17 background signals were less favourable for patterns to develop that can bring cold to the UK, but if low solar activity and neutral ENSO cannot deliver something then what can?

Mentioned this a number of times but the winters of 1911-14 were not brilliant and that was during a very deep solar minima. Next great winter was 1916-17 and that was very near solar maximum

[SLEETY]

So the first two weeks of january are according to the models another  writer-off for bitterly cold weather arriving.

Thats another winter gone then  with a chance of seeing bitterly cold weather arriving at the coldest time of the year then.

Still time for one decent cold outbreak,let’s hope for st least a sign even for a change in the outlook from Mid- Jan onwards.

Refuse to believe we can go 3 whole months with this pattern locked in,whatever the seasonal models are showing.

[Ali1977]

JET digging south a little, Scottish ski resorts should smile at this - should it happen 

[Methuselah]

Too early for getting over-excited (or maybe even for waking up!); but, at T+183, there's the barest smidge of a possibility of a channel-runner? Model-watching, just now, is like watching Mrs Brown's Boys, in the faint, vain hope of finding a laugh...?

    

[bluearmy]

The 06z gfs has interest .....the runner is a bit too deep but I guess if it wasn’t then it would be further south and of no interest whatsoever !

Then some cold zonality followed by that big height rise to our ne ...... some continuity on this would be good !

[SLEETY]

ECM OP was a mild outlier for most of the latter stages of the run,done that a lot this winter,so perhaps gfs is onto something.

[Thundery wintry showers]

The GFS 06Z op reminds me of the southerly tracking low that brought a surprisingly widespread snowfall on 22 January 1988:

But I agree with Nick F about the GFS cold bias at that time range, particularly with regards over-egging cold incursions from the north-western quarter of the compass.

Edited January 1, 2020 by Thundery wintry showers

[Anthony Burden]

GFS ends high pressure dominance and brings a pin ball low over the south of U.K. which if it ever came off

could bring that magical white stuff.Something to keep all cold fans interested .

[Methuselah]

Oh poo! Y'all're no doubt be surprised to learn that that channel-running LP has virtually no support at all from the GEFS (Londonshire) ensembles!

    

    

And neither (thanks TWS!) does the 'colder' outlook, in general...Och well, that's Happy Hour done with, for another day?

Edited January 1, 2020 by General Cluster

[Ali1977]

3 minutes ago, General Cluster said:

Oh poo! Y'all no doubt be surprised to learn that that channel-running LP has virtually no support at all from the GEFS (Londonshire) ensembles!

    

    

And neither (thanks TWS!) does the 'colder' outlook, in general...Och well, that's Happy Hour done with, for another day?

Yeah, I was hoping for a bit of support but nothing!! The Op is more powerful than the ENS though, so could lead the change 

Edited January 1, 2020 by Ali1977

[Anthony Burden]

GEFS operational 2 meter temp for London keeps around or below 5c for more than 7 days not bad let’s hope

its showing the right way more than the ensembles.

[snowray]

1 hour ago, SLEETY said:

ECM OP was a mild outlier for most of the latter stages of the run,done that a lot this winter,so perhaps gfs is onto something.

Yes a clear outlier, here are the ENS for London and Milan that demonstrate this.

 

The models have really struggled with the low pressure down towards southern Italy. GFS had the low over Northern Italy the other day but has now shifted it eastwards over Greece, ECM had the low even further east for a while closer to Turkey.

So both models were way out. I know that GFS usually gets knocked but in the end it was a blend of the two, and UKMO, that was close to the correct solution, although UKMO had been running with the ECM. Shame we don't have a model that takes input from the big three and does a mean, although I think someone said that the ICON sort of does this.

 

 

 

 

 

Edited January 1, 2020 by snowray

[legritter]

Hi gang ,hang on in there , a lot of uncertainty past day10 .seen this type of dank high pressure many a time change to Arctic bliss .many long range forecasts past 10 days are currently uncertain of synoptics, so tonight folks we may see some BOOM BOOM charts ,never give up ,and giving up on the first of January is complete defeat with many weeks of winter left. Loads of very cold Air to our north, and hints from models today that the jet is trying to move south again .Happy new year to you all, Stellas all round gang, cheers .

[Catacol]

Happy New Year everyone - new decade, new futures perhaps.

Plenty to be fairly gloomy about at the moment. Horrible ECM op in the semi reliable 

and EPS at 240 not looking much better. Notice the NE US ridge helping create a very flat and relatively mild jet into the North Atlantic with little opportunity for meridionality.

The only positive to that context might be less tendency for vigorous Atlantic lows, but it isn’t conducive to the kind of wave break we need for a higher latitude block. And NH snow cover now at an all time modern recorded era low 

 

And all this in the context of the biggest spike in AAM of the last few months.

So what’s happened? First of all it is worth countering the negatives with a degree of positivity. The blocked pattern that was expected around now has appeared - it just hasn’t managed to get sufficient amplitude to push the block higher. And it is worth following this up by saying that an unsettled first half of January was also on the cards given broad scale reality of the ebb and flow of the Pacific signal. So developments sit within the expected envelope even if they are at the disappointing end of what is/was possible.

However what has happened that is definitely not good is that the vortex has recovered much more effectively than was perhaps expected might happen 3 weeks ago, and slightly above average stratospheric westerlies have coupled to the troposphere more strongly than was hoped. As the AO increases and tropospheric westerlies engage dynamically it makes it less easy for waves originating from the equator to impact at higher latitudes. I read a really good analogy in another place - referring to the vortex giving the wave pattern a “buzz cut” - says it pretty much as it is! 

With one driver (the vortex) in control above and beyond the others at present it therefore needs either a substantial increase in the influence of another driver, or a decline in the dominance of the vortex. In the next fortnight this looks unlikely. Beyond that 2 possibilities - renewed Pacific signal at high amplitude towards month’s end that can knock the clippers out for the barber’s hands, or vortex stress in the context of some long term precursor patterns that have been broadly positive. A bit of both would be best possible outcome. SSTs are ok, QBO has turned - solar not whipping up jet activity.

So right now it’s hard work, but there is a lot to happen before winter turns to spring, and the majority of punters always said this winter was likely to deliver at the back end (if it was going to deliver at all...)

 

 

Edited January 1, 2020 by Catacol