Model Output Discussion - Cold spell ending - what next?

[Don]

EC46 still looking rather mediocre into February.  Some potential later on but any cold does not look sustained to me with heights not retrogressing far enough north

Edited January 17 by Don

[Augusta Snow]

9 minutes ago, Don said:

EC46 still looking rather mediocre into February.  Some potential later on but any cold does not look sustained to me with heights not retrogressing far enough north

Hi Don, it wasn’t that long ago the 46 was looking fantastic for this current cold spell and beyond. I for one won’t be worried by these charts. 

[WYorksWeather]

ECM ensembles are very much the same as GFS. Mild as far as the eye can see. Possibly even bringing in the 22nd as an exceptionally mild day as well as the 23rd, and then staying milder than average right to the end. 

The meteogram for Reading is also simple and straightforward. Overwhelming likelihood of westerlies and south-westerlies for the foreseeable, above average temperatures by day and night. Yes there's a drop off once you get past the 23rd, but only from exceptionally mild to significantly milder than average.  

I'm all for optimism, and we will no doubt have further chances in February, but I'm not going to attempt to sugar coat this one!

 

[Rocheydub]

For me, as much as I love cold and snow, the real watching brief is for this bloody storm on Sunday... That could lead to a red warning if it is any way close to how it's being modelled. Lot's of rain too, something I think we can all agree is not needed...

[Don]

11 minutes ago, Augusta Snow said:

Hi Don, it wasn’t that long ago the 46 was looking fantastic for this current cold spell and beyond. I for one won’t be worried by these charts. 

I believe it did yes!  Always to be taken with a pinch of salt.

[Rain All Night]

A summary of this afternoon's model runs.

Deterministic runs up to day 7 (Wed 24th)

Two upcoming lows to endure, the first one Sunday PM into Monday AM (this one perhaps with a sting in its tail), the second one Tuesday PM into Wednesday AM. All models show that second system being followed up with a minor ridge, which looks chunkiest on the ECM.

Ensemble means at days 10 & 13 (Sat 27th & Tue 30th)

Nothing much showing, aside from the likelihood that the further southeast you are, the drier you may be in the closing days of January.

Edited January 17 by RainAllNight

[blizzard81]

I don't take any op seriously after 7 days tops, whether it be ecm, gfs etc. There's a reason why ukmo ops stop at 168hrs. Anything after is not really worth taking seriously. With this in mind, the ecm op run this evening is definitely an upgrade compared to yesterday's. Compare this evening's 168hr chart to yesterday's 192hr chart. Poles apart if you excuse the pun. After 168hrs, the ecm flattens again but let's see if this improvement grows as we get to the 5/6 day timeframe. Things could develop rapidly here - and in a very good way for those of a cold persuasion. 

[joggs]

9 minutes ago, blizzard81 said:

I don't take any op seriously after 7 days tops, whether it be ecm, gfs etc. There's a reason why ukmo ops stop at 168hrs. Anything after is not really worth taking seriously. With this in mind, the ecm op run this evening is definitely an upgrade compared to yesterday's. Compare this evening's 168hr chart to yesterday's 192hr chart. Poles apart if you excuse the pun. After 168hrs, the ecm flattens again but let's see if this improvement grows as we get to the 5/6 day timeframe. Things could develop rapidly here - and in a very good way for those of a cold persuasion. 

The GFS ops were fairly decent over the predicted breakdown of our current spell far out imo.

[Mcconnor8]

1 hour ago, Rocheydub said:

For me, as much as I love cold and snow, the real watching brief is for this bloody storm on Sunday... That could lead to a red warning if it is any way close to how it's being modelled. Lot's of rain too, something I think we can all agree is not needed...

GFS 18z looks very rough during the day and overnight into Monday.

And Tuesday night doesn't get any better.

 

Edited January 17 by Mcconnor8

[blizzard81]

1 minute ago, joggs said:

The GFS ops were fairly decent over the predicted breakdown of our current spell far out imo.

The ops, whether they be gfs or ecm tend to do much better at handling mild breakdowns. I suspect most know this. They find it much more difficult when there is a possibility of meridional/amplified patterns emerging. Gfs often spots these way out but only spasmodically. Ecm initially doesn't want to know, gfs roller-coaster ensues, ecm sort of jumps on etc etc. The amplified patterns are still obviously very difficult for the models to get a grasp of, hence my own advice of sticking to 7 days tops in situations like this. 

[Eagle Eye]

I'll be using the 12Z mean because I can't be bothered for the 18Z one to fully roll out except for the reanalysis.

It appears to me that the combined reflection, MJO phase 1 and high GLAAM led to our eventual pattern but the late strengthening of the S.D. of the phasing and the wave reflection being late to the party meant it was delayed quite significantly looking at the pattern. I remember it was modelled to be around the early part of January then the GFS picked up on the signal to delay it for a week or so late December for some reason.

The actual response makes sense, whilst a delayed response and hence the phase 2 response quickly forced the pattern towards a zonal disposition despite the slightly favourable momentum perhaps built-up over the north Atlantic though it was falling, I suspect. As we move towards phase 2 and 3 over the Indian Ocean and an between phase 4, the zonal pattern is favoured and that can be hard to not get stuck with for a while. Especially as the Greenland pattern seems to be moving towards a complete flip which is harder to get rid of than a high there.

As you can see there is some forcing for the potential east Scandi high type that could be forced later on into the output however, it's still favourable for a zonal flow because there's not much energy going into actually forcing it polewards. So, we'll probably stay more zonal with a loaded Greenland pattern and no mid-Atlantic ridge either.

Then, as we move out of phases 2,3 and 4's response, we go towards a phase 5-6 phase supportive for rising GLAAM and the tropospheric forcing poleward to displace andor separate the zonal jet becomes a possibility both in MJO and GLAAM responses aiding poleward forcing of a RWT in certain areas. I suspect what we're seeing now towards the end of the charts. That appears to be helping the weakening of the Greenland high signal w/+VE anomalies leaking over the north and once that +VE wave exits the zonal jet part of the USA w/the rising AAM, it could force towards Greenland stronger than the mean would see it to further weaken the state. Then, the Alaskan ridge becomes more Alaskan centred again and so takes over late January potentially aiding a Greenland high setup proper, which is slightly favoured early-mid February before there's no real signal at all but that's quite far off to be that bold and it could well be a Scandi block instead.

So as we go towards that phase 6-7 that appears fairly likely, it becomes about how much momentum is input, which at the moment seems to be similar to what forced the Greenland high, then about how the response to that is and when. Will be interesting to see. Also, a very possible Strat driver with an omega block over the Ural area favoured on both phase 6 and 7. The Alaskan ridge losing energy is a possible sign of a displaced vortex over North America or split if that Ural wave can happen, more favourable towards a good zonal response here either reflection or SSW wise. That's a bit of a reach this far out but would be a 4th warming if it did occur according to Simon Lee (1st warming upper Strat based, 2nd being the one that caused the reflection, 3rd being the expected weak major or fairly strong minor warming occurring over the next couple days with little surface response I suspect and 4th being this one if it could happen) and would be impressive to see in and of itself.

Then going beyond the rising AAM over the next couple days, there's a weak frictional torque response slightly before another +VE mountain torque event significantly which has been supported on the last few CFS runs, is very possible probably in response to phase 7 and so is that the signal for the +VE EAMT event forcing a very strong Omega block for potential Strat vortex weakening or reversing, very possibly. However, it's a 4 member run and is mostly deviated because the 2 large +VE EAMT events on those members are very significant so it's 50/50. However, does seem that a +VE EAMT event is likely, member 3 has it and member 2 just appears to be slower to move towards it.

What would that high orbit GLAAM combine with? A late Winter phase 8 and phase 1 potentially given the MJO seems to be probably going towards them by that point. However, the strength of those phases is quite hard to predict this far in advance. We'll have to see. Winter is far from over yet though.

[Jason M]

Well, just had a run through the GEFS at 300 hours. I think the kindest thing to say is that by the time we all wake up this set will be gone 

[Gowon]

The GEM shows how quickly things can change:

 

Edited January 18 by Gowon

[LetItSnow!]

30 minutes ago, Gowon said:

The GEM shows how quickly things can change:

 

Did not expect to see that this morning! More of that please.  Would really love to see a flip to something more cold favourable in the models around this time. I don’t expect that to happen but at the same time I do have a feeling something is afoot. It would be great if we didn’t have to wait long. Maybe we’ll see a reverse of the normal and see the models finally pick out a rapid shift in the atmosphere. The cold is running out across America so perhaps the Jet will lose its steam soon. All I know is I’m sick of typing the word “telecommunications”. Bring on the flip!!!

[That ECM]

10 minutes ago, LetItSnow! said:

Did not expect to see that this morning! More of that please.  Would really love to see a flip to something more cold favourable in the models around this time. I don’t expect that to happen but at the same time I do have a feeling something is afoot. It would be great if we didn’t have to wait long. Maybe we’ll see a reverse of the normal and see the models finally pick out a rapid shift in the atmosphere. The cold is running out across America so perhaps the Jet will lose its steam soon. All I know is I’m sick of typing the word “telecommunications”. Bring on the flip!!!

Gem is interesting. What it does between 26th and 28th I’m not sure ive seen happen before in reality. Others may well be able to recall a time when it did.

other than another move away from a flat pattern there’s still much inconsistency. Fascinating.

Edited January 18 by That ECM

[Lukesluckybunch]

I wonder what the gem is seeing this morning!

[Zero Visibility]

Morning gang, had another dusting overnight which was never forecast, just sprung up over my area out of nowhere. Just goes to show you get the cold embedded the surprises will follow! Also I think someone on here got their wish for a Pembrokshire dangler

Anyway Gem this morning keeping the interest alive, let's hope its not long before everywhere can get a good white coating!

 

[TillyS]

We are about to go from bitter arctic to very mild south-westerlies. In fact, an unusually warm week ahead. We may see some double-digit nights and daytime maxima as high as 15C+. In the words of last night’s BBC Meteo Group forecast: “incredibly mild."

The Iberian high is evident on the UKMO output, which has been a persistent presence. Quite difficult to ‘scroll past’ this and with SSTs around the Azores 2C-3C above mean, we are in the firing line for warm winds:

 

 

[winterof79]

Maybe the reasoning behind the METO extended expected frequency of colder interludes through February

The polar vortex is acting up | NOAA Climate.gov

WWW.CLIMATE.GOV

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The latest forecast says a major disruption of the polar vortex is on its way, but the stratosphere has been acting up for a while. Our...

 

[KTtom]

The problem with height rises to the east is if they dont migrate far enough north, with a section of deep vortex stationed over Greenland we often get stuck in no mans land with mild southerlies as per ECM.

On a more seasonal note, woke to a decent snow shower here in W Wales which has left a dusting.

[TillyS]

0z ECM continues the 0z UKMO theme of very mild south-westerlies, with the Iberian / Euro high back in situ:

 

A mild final third to January. The real meteorological story for the UK will be strong winds and flooding, as well as some unseasonably mild temperatures.

[winterof79]

Wouldn't it be ironic if Iberian heights pushed North and inflated a Scandi.Just saying.

Edited January 18 by winterof79

[Nick2373]

12 minutes ago, TillyS said:

0z ECM continues the 0z UKMO theme of very mild south-westerlies, with the Iberian / Euro high back in situ:

 

A mild final third to January. The real meteorological story for the UK will be strong winds and flooding, as well as some unseasonably mild temperatures.

At ten days out that's FI The pattern can change over two to three days even by next Wednesday the temps are around the 9c-10c mark not exactly mild considering the wind is from a WSW direction.    

[Gowon]

57 minutes ago, LetItSnow! said:

Did not expect to see that this morning! More of that please.  Would really love to see a flip to something more cold favourable in the models around this time. I don’t expect that to happen but at the same time I do have a feeling something is afoot. It would be great if we didn’t have to wait long. Maybe we’ll see a reverse of the normal and see the models finally pick out a rapid shift in the atmosphere. The cold is running out across America so perhaps the Jet will lose its steam soon. All I know is I’m sick of typing the word “telecommunications”. Bring on the flip!!!

Same, but I wasn't surprised- both the GFS and the ECM has played with the idea of a quick route to cold - the ECM had that wedge of heights first which would have led to the same evolution as the GEM. 

7 minutes ago, KTtom said:

The problem with height rises to the east is if they dont migrate far enough north, with a section of deep vortex stationed over Greenland we often get stuck in no mans land with mild southerlies as per ECM.

On a more seasonal note, woke to a decent snow shower here in W Wales which has left a dusting.

That looks full of potential to me.

[Gowon]

20 minutes ago, TillyS said:

0z ECM continues the 0z UKMO theme of very mild south-westerlies, with the Iberian / Euro high back in situ:

 

A mild final third to January. The real meteorological story for the UK will be strong winds and flooding, as well as some unseasonably mild temperatures.

Hopefully auntie vortex and uncle barty won't overstay their welcome.