Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[Cheshire Freeze]

GFS Op starting to move toward its ensembles more and more with the idea of extending the surface cold and giving any Atlantic weather trying to move in a tough time.I wonder if there will be some decent Easterly solutions among the ensembles and the cold gets lengthened still further?

UKMO not at all interested so it will be interesting to see where the ECM goes.

Is the beast stirring from its slumber?

Polar heights forming on that day 9 chart too. Hard to take it too seriously though unfortunately whilst the UKMO refuses to back the idea.

We stay cold well into FI, and by day 11 we're staring down the barrel of a lengthy cold spell.

Edited January 18, 2015 by CreweCold

[Mucka]

Polar heights forming on that day 9 chart too. Hard to take it too seriously though unfortunately whilst the UKMO refuses to back the idea.

 

Perhaps CC and it does go against MetO forecast, we will know more after ECM and especially after this evenings runs but I did say last night it was a strengthening signal withing GFS ensembles and there could be some big changes today. That is certainly true of GFS Op which stays cold throughout the run at the surface, more or less, and if the ensembles continue with that trend it certainly can't be dismissed.

Further GEM is trending the same way this morning compared to its previous runs. Still nothing like GFS but it is heading in the same direction.

 

Edited January 18, 2015 by Mucka

[Cheshire Freeze]

Perhaps CC and it does go against MetO forecast, we will know more after ECM and especially after this evenings runs but I did say last night it was a strengthening signal withing GFS ensembles and there could be some big changes today. That is certainly true of GFS Op which stays cold throughout the run at the surface, more or less, and if the ensembles continue with that trend it certainly can't be dismissed.

Further GEM is trending the same way this morning compared to its previous runs. Still nothing like GFS but it is heading in the same direction.

 

Pretty sure that's a full blown SSW being signified at the end of the run too, warming directed straight into the heart of the vortex. Looks like 2013 all over again potentially. Matching it this month pretty closely (except conditions slightly more conducive for slider snowfall then).

[Mucka]

Pretty sure that's a full blown SSW being signified at the end of the run too, warming directed straight into the heart of the vortex. Looks like 2013 all over again potentially. Matching it this month pretty closely (except conditions slightly more conducive for slider snowfall then).

 

Oh yeah, that will give the strat guys something to think about but so far out unfortunately. 

 

 

Just skimmed through GFS ensembles and I would say the signal is weaker than the 18z, Op comes along, ensembles drop off, typical.

Stillenough uncertainty in there though to suggest that anywhere past 120h is FI.

Have to laugh that the Op and control were among the mildest runs all yesterday and today they will probably be among the coldest.

 

 

Still control supporting the Op supporting ensemble trend...

If ECM comes along, well that would set the cat among the pigeons.

 

Edit

Ensembles now delay any warm up until the 25th. If they keep adding a day every day it will be a long winter. 

 

 

Also quite a split appearing.

 

Edited January 18, 2015 by Mucka

[TSNWK]

Morning Mucka and Cc. Has the UKMO shifted at all towards extending the cold or not? In comparison to yesterday afternoon.

[Mucka]

Morning Mucka and Cc. Has the UKMO shifted at all towards extending the cold or not? In comparison to yesterday afternoon.

 

Good morning, short answer, no.

 

[TSNWK]

Good morning, short answer, no.

 

Many thanks for the reply.. Well I personally think that we need to see something postive from the UKMO, surely it must be better for modelling our part of the globe than a global model..

[shaky]

Ukmo 00z is not bad at all!! Its a brilliant start to the day peeps!! Compare yesterday's 00z to todays on ukmo and everything is being pushed westwards and there more trough disruption going south east than east!! Compare yesterday's 120 hours to todays 96 and thats potentially another snow event for England! !

[West is Best]

Ukmo 00z is not bad at all!! Its a brilliant start to the day peeps!! Compare yesterday's 00z to todays on ukmo and everything is being pushed westwards and there more trough disruption going south east than east!! Compare yesterday's 120 hours to todays 96 and thats potentially another snow event for England! !

 

Could you possibly post up some supporting charts please? Everything looks further east to me on successive runs and the UKMO looks pretty progressive to my eye:

 

 

The BBC forecast for next week is only now talking of snow 'at first' for Northern Ireland and then Scotland, which might be going a tad far but I'm not sharing the excitement for the UKMO output. The fax chart for Wednesday leaves Britain in a cool north-westerly but it's no slider:

 

 

There will be some interest at the latter stages of the 0z GFS because it shows an easterly of sorts and a bit of a battleground later in the run. My main concern for the first half of next week remains the upper air temps. Whilst taking on board the surface cold, the benchmark -5C850hPa is not present, so it could be marginal. I hope not.

 

 

I've been thinking these thoughts for 36 hours without posting but those two outputs don't make me feel confident at the moment about snow prospects. I hope I'm talking nonsense, and also that the ECM comes in with a belter.

[shaky]

Ecmwf pushes scandinavian further west at 144 hours and we have got another slider sliding through which was not there on last nights 12z!!for me theres upgrades this morning!!

[Mucka]

Have to agree with WIB on UKMO but I think it is an improvement on yesterday's at least as Shakey said

ECM is somewhat better at 144 and is a little further West.

 

 

Still very marginal for any snow to low levels though I would of thought even though it limits the warm sector ahead.

Edited January 18, 2015 by Mucka

[shaky]

Have to agree with WIB on UKMO but I think it is an improvement on yesterday's at least as Shakey said

ECM is somewhat better at 144 and is a little further West.

 

 

Still very marginal for any snow to low levels though I would of thought even though it limits the warm sector ahead.

mucka one thing for sure is that scandinavian high is absolutely massive and there are no deep lows to fight against so there should only be one winner here!!! Another thing go back into the archives lets say just 2 or 3 days ago and that scandinavian high was nowhere near as strong! !

[Great Plum]

The -5 line advances west back across the country at 168hrs on the ECM...

If nothing else, the Scandi high seems to be modelled stronger every model run...

[Mucka]

mucka one thing for sure is that scandinavian high is absolutely massive and there are no deep lows to fight against so there should only be one winner here!!! Another thing go back into the archives lets say just 2 or 3 days ago and that scandinavian high was nowhere near as strong! !

 

Hi Shakey. The upstream pattern isn't favourable on UKMO really and the high is a long way back, actually a Russian high ridging into Scandinavia but the trend is going the right way.

ECM is a little better upstream and a touch further West but doesn't quite get there.

 

 

Even so, as you noted, the block to our East is looking stronger with each run.

[snowangel32]

Hi Shakey. The upstream pattern isn't favourable on UKMO really and the high is a long way back, actually a Russian high ridging into Scandinavia but the trend is going the right way.

ECM is a little better upstream and a touch further West but doesn't quite get there.

 

 

Even so, as you noted, the block to our East is looking stronger with each run.

Look at the low over greenland and so much energy in that area any waa attempt or ridging will surely get crushed but it does seem to want to have fight with the atlantic each run prolongs the cold spell a touch more. Also worries me that the uppers are not that great for low lying areas in the south and west. Or am i barking up the wrong tree.

[I remember Atlantic 252]

Ecmwf pushes scandinavian further west at 144 hours and we have got another slider sliding through which was not there on last nights 12z!!for me theres upgrades this morning!!

 

GFS best for cold this morning, trend seems to be to move everything west, battle taking place, hope to see ECM trending towards GFS instead of powering the Atlantic in

[West is Best]

GFS best for cold this morning, trend seems to be to move everything west, battle taking place, hope to see ECM trending towards GFS instead of powering the Atlantic in

 

Again, could you possibly post supporting charts for this? I don't see things being moved west so either I need to go to Specsavers or, better still, would love to see some charts to back this up. Or do you mean around T200+ when there's more of a battle? Please spare me my confusion with a chart or two. Shaky, likewise, if at all poss?

[Frosty.]

We have west is best saying everything looks further east and other comments saying it's being pushed further west, anyone new to the models or just the casual observer will wonder what is going on! confused?..you will be if you read this morning's comments.

[Great Plum]

Again, could you possibly post supporting charts for this? I don't see things being moved west so either I need to go to Specsavers or, better still, would love to see some charts to back this up. Or do you mean around T200+ when there's more of a battle? Please spare me my confusion with a chart or two. Shaky, likewise, if at all poss?

  

The -5 line advances west back across the country at 168hrs on the ECM...

If nothing else, the Scandi high seems to be modelled stronger every model run...

richard, the only thing I noticed with a westward advancement is in my post above...

However, it does appear (and I think it's Mucka that has been posting the ensembles) that the cold is being extended to the weekend; my assumption is that the 'sliders' are further west allowing for more of a continental feed afterwards...

[TEITS]

Again, could you possibly post supporting charts for this? I don't see things being moved west so either I need to go to Specsavers or, better still, would love to see some charts to back this up. Or do you mean around T200+ when there's more of a battle? Please spare me my confusion with a chart or two. Shaky, likewise, if at all poss?

Morning Richard.

 

What they are referring to is the fact that the 0Z GFS now shows the UK being influenced by the high to our NE right into F.I. The 0Z GFS output does not surprise me as slowly it has been trending this way since yesterday. Remember it was only a few days ago the GFS wanted to introduce milder W,lys on Friday!

 

As for next week and I must admit I share your concerns with regards to snowfall. For our location I am also concerned about the fronts weakening as they cross the country. Whilst I can see snowfalls I cannot see disruptive snowfalls except maybe further N especially on higher ground.

 

Here we go yesterdays 0Z showing W,lys at +150.

http://modeles.meteociel.fr/modeles/gfs/archives/gfs-2015011700-0-150.png?0

 

Todays for the same time.

http://modeles.meteociel.fr/modeles/gfs/runs/2015011800/gfs-0-126.png?0

Edited January 18, 2015 by TEITS

[chicken soup]

Its t48 now to this progged event and we still dont have a definative answer from the models as to weather the slider even happens ....never known Fl to be 48hrs lol.....surely things will be decided one way or another come the 12z runs.

[bluearmy]

Interesting times ahead. Fwiw, although the scandi block looks to be gaining traction this morning, the gefs and anomolys are fairly inline with the ECM extended eps from yesterday's runs.

That would lend credence to the nw/se jet axis and systems heading in and disrupting se into se Europe. Where do we sit on the disruption? At the moment, the anomolys place us pretty well underneath it whereas the mean has it just to our east. so we remain in the raffle for week 2. We already know we have tickets from the winning book week 1.

the question you should be asking yourselves is if the Russian ridge is to be more of a player than the ensembles perhaps see, then how will that play out against what looks like a strong Atlantic jet ? Of course, the contra to that should be if the Atlantic jet and Azores ridge prove to be stronger than the ens see in which case we know the answer to that one!

[IDO]

Lots going on and as others have said as we draw closer towards the possible second slider around T150 the models will start to flip flop again IMO. Will it wont it slide part 2. The GEFS clustering is around 45% trying to slide at D6-7 and 55% not, with all sorts of swinging from then on. The good news is that 100% support for the slide now at T48 and remember there were at T72 about 33% of the GEFS who had this sliding scenario wrong so another 2-3 days before the second slider is resolved.

 

Too early for snow chances and hot spots. IMBY the chances have improved a little from yesterday's runs but still nothing better than an evens chance.

 

With the MJO showing as a driver at the moment I cannot see any pattern digging in, though I would be surprised if we returned to zonal, a MLB looks more likely:

 

 

With the PV coming under pressure in the strat in FI we may get a proper SSW, so lots of positives as we enter the last half of Winter.

Edited January 18, 2015 by i'm dreaming of...

[nick sussex]

Morning all

 

Not a bad start to the day with just the UKMO being a bit difficult however to put to bed whether the UKMO is better or worse than yesterday, we don't have the 12hr steps but if you compare its 00hrs yesterday with todays 00hrs it has made a large correction with the troughing to the west both in terms of placement and tilt:

 

Yesterdays 00hrs to T144hrs:

 

 

Todays to T120hrs:

 

 

You'll see in yesterdays the centre of the low is further east and the tilt of the trough is positive so the energy is going ne and over the top, in todays the centre further west, weaker with the tilt more neutral slightly negative with energy going more north.

 

We're still seeing differences between T96 and T120hrs as to the clearance of shortwave energy and whether this separates cleanly, the GFS clears this, the ECM takes longer, the UKMO not at all.

 

This is important because the clearance allows ridging from the east to extend a little bit further west.

 

In terms of which output is correct hard to say but in recent days the UKMO seems to have been playing catch up.

 

 

[West is Best]

Thanks for the above folks which makes things a little clearer. I can definitely see the one you are referring to Great Plum: on the ECM the 850hPa comes back west for 24-36 hours as you posted, and with charts to back it.

 

T144 the -5C 850hPa is off the east coast

T168 it pushes back west

Then gets pushed away east again

As the Atlantic returns

 

For the period up to T144 I'm still not really getting the 'westward movement' and as TEITS (good morning Dave) says it looks marginal at best. But maybe Steve Murr will explain again why the surface cold etc. will withstand the frequent absence of -5C 850hPA?

 

Edit: Nick, do you mean to be posting the UKMO charts for Friday 23rd January? I thought folks were referring to Monday-Wednesday's slider re westward movement?

Edited January 18, 2015 by West is Best