Model Output Discussion - 05/01/2016 18z onwards

[nick sussex]

Well another day passes in the surreal world that is called the model discussion. Its a comforting place, you know this weird world where all that matters to the majority is being able to run out and play in the snow, myself included.

At times during the last week its been like pulling teeth to get any model agreement on  cold and snow. We saw the Greenland high and then the dreaded shortwave sticking two fingers at us, the deflation in mood, the denial, acceptance and before we even had time to grieve we're back to thoughts of it might just happen!

Overall the week has been bizarre, normally when the outputs start going the wrong way theres no way back so it does come as a pleasant surprise to see them pull back from the precipice and try and plot another route.

Whilst this route doesn't have the bells and whistles of suggestions earlier in the week at least there is a route.

Okay you've probably had enough of that wishy washy rather melodramatic starter!

Putting my more suit and tie on approach the interest is really whether the cold that comes(hopefully) can hang on or whether its cold then milder.

Even the GFS which has not been popular today managed to extend the cold on its 18hrs with that high ridging ne before flattening. Putting aside whether the MJO is the best signal to focus on simply looking at its composites shows phase 7 more amplified Atlantic, phase 8 more Euro high, phase 1 block to the ne.

Looking at the ECM that manages to avoid the Euro high helped by that digging upstream troughing and jumped from phase 7 to a half-hearted phase 1.

There has been much conjecture over the MJO influence in ENSO positive years but we mustn't forget that theres still a strong correlation with it and the pattern to the west of the UK, as long as the El Nino is not in the warming stage but either flatlining positive or declining. Its currently in a slow decline but it will take time to drop significantly.

Anyway in terms of where we go towards day ten of course the suggestion is that any block to the ne won't hold on and I suppose that's where the money would be but as we've seen over the last week there does seem a lot of volatility in the outputs. Its a very strange strong El Nino which was supposed to completely run riot, of course as we saw it did exactly that during December but for those who keep track of NCEP's thoughts they have concluded that the MJO has destructively interfered with the El Nino and this has played a big role in now shuffling up the NH pattern.

I think most in here would just like to see a week of decent cold and snow chances and we still have a chance of that and if things turn somewhat less cold for a time it would be a bit more palatable then.

We'll see over the coming days what the models want to do, personally lets hope for a bit less drama!

Edited January 10, 2016 by nick sussex

[ALL ABOARD]

Gem and ukmo both rebuild the greenland heights!!!! Gfs has a go but does not quite get there. Interesting ecm coming up! 

 

That should read links the greenland heights with atlantic heights.

Edited January 10, 2016 by ALL ABOARD

[Cheshire Freeze]

Oh my UKMO why do you keep doing this to us?! Best day 6 chart for a couple of days

 

[Aaki Khan]

UKMO Looking Good Throughout. 

[ALL ABOARD]

1 hour ago, CreweCold said:

Oh my UKMO why do you keep doing this to us?! Best day 6 chart for a couple of days

 

Gem isnt far behind at 144 !

[Cheshire Freeze]

2 minutes ago, Aaki Khan said:

UKMO Looking Good Throughout. 

UKMO would be very cold day 7+ with a nice Greenland high

Edited January 10, 2016 by CreweCold

[Mucka]

Yes UKMO and GEM both very nice but somewhat surprisingly GFS still not on board though it is ever so slowly backtracking and prolonging the cold

 

Edited January 10, 2016 by Mucka

[Cheshire Freeze]

1 minute ago, ALL ABOARD said:

Gem isnt far behind at 144 !

I pray ECM shows this. An all Euro vs GFS would be very interesting.

[snowangel32]

Gfs 00z is in a snow giving mood with nationwide snow I would bank these. 

Edited January 10, 2016 by snowangel32

[Mucka]

UKMO/GFS comparison 144

I'm struggling to remember such a prolonged, pronounced and persistent difference in the models

[snowangel32]

1 minute ago, Mucka said:

UKMO/GFS comparison 144

I'm struggling to remember such a prolonged, pronounced and persistent difference in the models

 

Surely something has to give today. 

[Mucka]

1 minute ago, snowangel32 said:

 

Surely something has to give today. 

LOL I said that yesterday and we are still waiting.

I guess GFS has moved from the more progressive breakdown to the less progressive breakdown so that's progress. of sorts. 

[snowangel32]

10 minutes ago, KasimWeatherQuarnford said:

Not trying to hype, and a fairly uncertain progression however the GEM is fairly concerning for my part of the Pennines and much of the Pennines.

 

UKMO pushes the worst of it back slightly but minimal next Thursday 

GFS good for snow v similar to 18Z but doing its usual thing with the Ott early breakdown 

 

ECM is now more than likely to go with UKMO and gem with the Greenland ridge 

such a good time to be having a slow upgrade, snow is now inevitable here but elsewhere ☂☃ the snow / rain boundary looks quite narrow on Thursday, looks like a real headache 

 

Yh you look in a sweet spot for a pasting, but with the models struggling it's hard to take anything at face value, but it does look odds on for some snow to a lot of the UK.

[snowangel32]

7 minutes ago, Mucka said:

LOL I said that yesterday and we are still waiting.

I guess GFS has moved from the more progressive breakdown to the less progressive breakdown so that's progress. of sorts. 

 

mucka is it me or are the models trying to go full circle to what they were showing a few days ago still not quite there but not far off. Exception gfs but even that looks better. Rare for upgrades long may it continue.

[Mucka]

47 minutes ago, snowangel32 said:

 

mucka is it me or are the models trying to go full circle to what they were showing a few days ago still not quite there but not far off. Exception gfs but even that looks better. Rare for upgrades long may it continue.

I guess they have in a way except we are now seeing a 3rd bite of the cherry instead of a first or second.

I know, I'm confused too. It is like Groundhog day regarding the Atlantic ridge.

It is really odd that GFS op has consistently gone for the flatter pattern and every time had support from the control and slow growing support within the rest of the ensemble suite while at the same time the other models have slowly gone the opposite direction. I really expected GFS to be more like the Euros this morning but I guess it is going to take a few runs of small adjustments rather than a quick flip to get where the other models are  - assuming it is wrong of course.

 

Edit

GFS ensembles SE England - certainly not moving back toward more prolonged cold as yet. Curious.

Edited January 10, 2016 by Mucka

[Great Plum]

Meanwhile, at the end of the GFS - easterly incoming!! 

[Spah1]

- ECM + 144

Cold

 

Edited January 10, 2016 by Spah1

[That ECM]

T 144 for all 3. I'm hoping ukmo is leading the way but none of them are poor.

[ICETAB]

Unfortunately ECM does not build heights over Greenland like we see on the UKMO chart at 120, nor do any of the other models.

 

[gottolovethisweather]

2 hours ago, CreweCold said:

Oh my UKMO why do you keep doing this to us?! Best day 6 chart for a couple of days

 

I can see an angel somewhere, even though we're not there yet I always believed this cold spell would have some legs but it also appears to have wings. 

Soon be time to discuss the specifics of will it, won't it snow in my back yard but certainly not quite yet folks. Right now, a wintry mix is a good description for sure for most of Lowland England but my gut feeling is that the -6c isotherm/850s will visit more times during January and February than most would have ever imagined, just a week ago. Just goes to show, do not write anything off anyone not even angels looking down us from above in our weather charts. 

Edited January 10, 2016 by gottolovethisweather

[Iceberg]

Ecm rock solid it's the cold from t96-168 with a promising med low to encourage the easterly. Nice 1030'pressure up over Iceland. Very very cold particularly for the south at t168

[Captain Shortwave]

Well the model drama is going to continue on through today.

Day 5 charts

UKMO

The ridge is re-building through the Atlantic and into Greenland by day 6, maintaining a northerly flow.

GFS

Still the flattest solution by far, it still brings that shallow low across from the Canadian trough, no other model does this evolution.So it turns drier and less cold as we go through next weekend.

ECM

The heights over Greenland are not as strong as on the UKMO, but the Atlantic ridge and overall evolution is similar but with a less amplified day 6 chart. However that deep cold over Scandinavia and Eastern Europe is starting to drift our way, the -12C isotherm over Holland by day 7 with a weak high over the southern tip of Norway.

It doesn't look quite like getting there as the high settles near the UK, but it is still cold at 850 level into the following week and very cold at the surface with hard frosts. Lets see what day 9/10 bring. Can we undercut that high and develop a stronger easterly.

Edited January 10, 2016 by Captain Shortwave

[Iceberg]

Academic as it won't be accurate but with little energy to the east of the tip of Greenland, 0 850s north of Iceland and the high being pulled nw it will remain cold with an increasing easterly component. 

Ec shows a clear week long cold spell with snow ice and freezing temps. 

[IDO]

A move towards the GFS by ECM this morning. It has downgraded the Atlantic High from 1040mb to 1030mb (it's propensity to blow up highs in high entropy situations). It has also changed the position and influence of the Azores Low, now much closer to the GFS take:

T144:     GFS: 

The net effect is that the high is not sustainable with respect to a Greenland connect and gets pushed away, as GFS have been showing in the last few runs; where the Azores low phases with the US trough to push the pattern east.

D7 ECM:   GFS: 

Very similar, though ECM remains better for cold for longer (is it over amping still?), though with its run to run changes I would expect ECM 12z to be different again tonight, where as GFS has been consistent.  There is a cluster of about 25% that support the ECM evolution by D8 on the 0z GEFS, so an evolution that is feasible now that ECM has stepped towards the GFS with respect to earlier developments. As for who is correct (post D7), I am as flummoxed as most on here.  All fluid and best to watch and learn so we can gauge what model is better in such future circumstances. Cold High on ECM from D7-10.

As for the UKMO it phases the Atlantic high into the Greenland High and that doesn't look likely from what the GEFS show. GEM decouples the Azores low with the US trough around D7 as further HP moves in (similar to ECM yesterday and now binned by the ECM 0z).

Edited January 10, 2016 by IDO

[Iceberg]

Ido re gfs consistence I disagree I've taken the gfs charts from 00z Saturday to just now. If we focus on the direction of the energy west of Greenland we can clearly see that on every run the gfs has put the energy more and more in northwards direction. Starting due east on Saturdays 00z and ending due north on today's 00z. 

Gfs is putting less and less energy south of Greenland. If the trend continues it will eventually lead to an ecm/gfs/gem mix.

gfs continues to try and put more energy into the  Atlantic but pulls away from it gets into the t144 frame..

just my opinion