Model output discussion - into 2018

[northwestsnow]

5 minutes ago, bluearmy said:

Broadly speaking the direction of travel is good with ridging to our east intensifying as the ens come into higher res and the pulses of northern arm have nowhere to go but into Europe to our south. that keeps us on the cold side but the way gfs and ecm orientate the ridge on the ops (and ens ) means that we don't advect any proper cold uppers into nw Europe and when the battleground develops, it's probably going to be nerf guns rather than rpg's. Steve has illustrated the better ukmo in this respect. 

The outlook remains cool/cold unsettled but with the ridging to our ene thrown in as a wild card it should remain busy on here for the foreseeable. 

Blue- the det was absolutely one of the mildest runs again!! Its becoming annoying we keep seeing these milder ops!!

That said, by day 10 we are in the game for the Atlantic disrupting

[northwestsnow]

6/7/8th especially!!

[TEITS]

Overall I think the output is great but probably for different reasons than some.

Let me start by saying I remain unconvinced this E,ly will bring as much as some hope for with the exception of N Scotland. I do agree the E,lys will spread S but by the time the low sinks SE the upper temps will be watered down. Currently an E,ly with upper temps of -8C is unlikely to bring snow showers to the E because the warming effect of the N Sea would bring rain/sleet instead.

I am much happier with the overall trend as I shall explain. The ECM beyond +240 would be very interesting because note the Atlantic is heading SE and at the same time colder air is heading S around the right flank of the high pressure over Scandi. The end result is possibly a much colder E,ly later on. Even if the block doesn't hold on and the Atlantic sweeps in, we are still looking at an amplfied jet in the Atlantic and possibly a cold, zonal spell.

I shall have a little ramp here and say in my opinion mid Jan onwards is looking very promising and its only a matter of time the arctic floodgates open from the N or NE or E. I know a front loaded winter was predicted but I see the opposite. The output really has a 1980s feel to it.

[northwestsnow]

The det shows as a rogue mild outlier on the Aberdeen ens this morning!!

[Nick F]

18 minutes ago, northwestsnow said:

EC det AGAIN one of the mildest solutions!!!

You can see from the EPS T850s mean, that the -4 to -6C temperatures gradient is further south (in means) compared to the deterministic

T+168

Det. EPS mean

T+198

det. EPS mean

[northwestsnow]

1 minute ago, Nick F said:

You can see from the EPS T850s mean, that the -4 to -6C temperatures gradient is further south (in means) compared to the deterministic

T+168

Det. EPS mean

T+198

det. EPS mean

Yes Nick, we seem to be almost constantly getting the mildest or one of the mildest options from the det.

Which is a bit of a concern?

[MR EXTREMES]

JMA and gefs look good.

JMA has dig of lower heights to our south.

Considering we already seen a couple of sliders already this winter tells us this could well prove useful in block slider situations.

Another few runs maybe couple of days then we shall know for sure.

I'm going for fully fledged Scandinavia block starting into Iceland then backing east into Scandinavia.

[Banbury]

@northwestsnow why is it a concern ???

[northwestsnow]

59 minutes ago, Banbury said:

@northwestsnow why is it a concern ???

Because the det is higher resolution..

 

Edited December 31, 2017 by Paul

[Nick F]

1 minute ago, northwestsnow said:

Yes Nick, we seem to be almost constantly getting the mildest or one of the mildest options from the det.

Which is a bit of a concern?

Is a tricky one to try gauge and foresee how it will evolve synoptically, the models notoriously struggle with trough disruption and subsequent build of high pressure to the north of the upper/surface lows that close off.

Ideally I would want to see a NEly evolve in the models rather than an Ely, as the the former would tap into deeper arctic sourced cold than an Ely, given not paticularly cold continental air over eastern Europe and western Russia atm.

[bluearmy]

13 minutes ago, northwestsnow said:

Because the det is higher resolution..

Fergie has tweeted they metoffice expect colder weather by next weekend due to changes in the pacific/n america but longivity of cold uncertain..

Whilst the det cannot be used for accurate forecasting post day 7, it does give a broad pattern indicator and also tends to give a heads up to a change from the eps mean/anomoly.  A good illustration of this is the digging of the Atlantic trough more to the sw as it heads se next weekend. That has served to push warmer uppers north just to our se and the jet pulse which should have gone into France is more muted as it has been spread around a larger area - tough to explain but the op led the way illustrating this and the eps spreads agreed. if there is a spread and the op sides with the spread then take note! 

If the gfs continues to trend away from colder uppers next weekend and ukmo follows suit later then sadly, the ecm op will have come out on top. There is still time for it to be wrong though! 

[SMU]

A rare lie in today- almost as rare as that UKMO 168!!!! :0 :0

GFS 06z continues the Models increasingly better shape of the Scandi high from run to run with the deeper cold curvature aligning better as well...

All we need is the ECM to wake up ! 

Remember the debilt ensembles may not be as useful as it to could be on the cusp of the warmer air ! Stick to the 500MB mean !

S

[northwestsnow]

2 minutes ago, bluearmy said:

Whilst the det cannot be used for accurate forecasting post day 7, it does give a broad pattern indicator and also tends to give a heads up to a change from the eps mean/anomoly.  A good illustration of this is the digging of the Atlantic trough more to the sw as it heads se next weekend. That has served to push warmer uppers north just to our se and the jet pulse which should have gone into France is more muted as it has been spread around a larger area - tough to explain but the op led the way illustrating this and the eps spreads agreed. if there is a spread and the op sides with the spread then take note! 

If the gfs continues to trend away from colder uppers next weekend and ukmo follows suit later then sadly, the ecm op will have come out on top. There is still time for it to be wrong though! 

GFS6z has removed the colder uppers for next weekend ..

 

[nick sussex]

Better GFS 06hrs run, nice changes working east from the Pacific more amplification there will effect the trough to the west of the UK.

Edited December 31, 2017 by nick sussex

[northwestsnow]

Just now, Steve Murr said:

A rare lie in today- almost as rare as that UKMO 168!!!! :0 :0

GFS 06z continues the Models increasingly better shape of the Scandi high from run to run with the deeper cold curvature aligning better as well...

All we need is the ECM to wake up ! 

Remember the debilt ensembles may not be as useful as it to could be on the cusp of the warmer air ! Stick to the 500MB mean !

S

Dont like 6Z steve-

Its noticeably less cold fri/sat as the colder uppers take an age to move south..

[northwestsnow]

Just now, nick sussex said:

Better GFS 06hrs run; nice changes working east from the Pacific more amplification there will effect the trough to the west of the UK.

LOL..

I just posted about how its taking an age longer to sink the colder uppers south next weekend-

[tight isobar]

Now thats a cold flow by any standards!..

And again a marked easterly will eventualy find colder infer!..

Cant complain given its a week away.

Edit: by now most should understand that even mobile/zonal weather is at times a distinct, annoyance via modeling.

An,easterly incursion-marked/or weak..

Will at this stage have lots of divergance/longevity/cold-850s/ position of placing-flow..so panic'ing about breakdowns-how cold it is are, atm pointless....look at the overall, shape of things evolving into the weekend....then account the above in.

Edited December 31, 2017 by tight isobar

[DIS1970]

Nothing to get excited about as this goes pear shaped yet again i'm afraid.

[bluearmy]

8 minutes ago, northwestsnow said:

GFS6z has removed the colder uppers for next weekend ..

 

 More concentrated pulse of the jet into France would have created a stronger more defined trough which, in turn, would have advected more cold westwards as the ridge intensified - another reason we aren't seeing. The flabby system we see now isn't good for coldies 

[Sweatyman]

So many confusing posts for this 6z

[Nick F]

Not exactly beast from the east on the 06z, but the NEly/Ely flow around the high migrating into Scandi will be raw I imagine but as per the parameters on the run would probably bring nothing more than stratus and drizzle to the east coast and maybe a little wintriness with elevation.

Trying not to over-analyse too much, given it will change, but the deep cold pool dropping down across Scandinavia is NW Russia bound given the northern arm of the bifuricated jet over the top of the Scandi high takes energy that direction. But we do tap into the western peripherals of this cold pool.

Still, for coldies, it's better than mild zonality with wind and rain that we have this week. Will certainly feel wintry in the easterly, but it doesn't look like a convective snow shower producer off the North Sea given the lack of deep cold.

Prefer to see a long draw NEly feeding direct into the deep cold pool dropping down across Scandi from the arctic rather than the long route of modified cold air around a Scandi high which mixes with less cold air over northern Europe. Still time for changes towards this colder feed though.

[bluearmy]

Just now, DIS1970 said:

Nothing to get excited about as this goes pear shaped yet again i'm afraid.

 Not sure what has yet existed to go 'pear shaped' .

we seem to be getting a handle on how the ridging will interact with the various players but detail still fairly sketchy. beyond day 8 and the Atlantic still favoured but is that into Europe or scandi or west of scandi ???

[northwestsnow]

2 minutes ago, bluearmy said:

 More concentrated pulse of the jet into France would have created a stronger more defined trough which, in turn, would have advected more cold westwards as the ridge intensified - another reason we aren't seeing. The flabby system we see now isn't good for coldies 

GFS6Z is a bust -

Far too much energy in the old Atlantic- esp the northern arm!! Looks very wet after a couple of days of an easterly waft..

[bluearmy]

1 minute ago, northwestsnow said:

GFS6Z is a bust -

Far too much energy in the old Atlantic- esp the northern arm!! Looks very wet after a couple of days of an easterly waft..

Less of a bust than the 00z was. Note the development of the low indicating some trough disruption - gfs post day 8 generally takes the jet ne rather than se. Time to see how many eps clusters there are.

[tight isobar]

5 minutes ago, Nick F said:

Not exactly beast from the east on the 06z, but the NEly/Ely flow around the high migrating into Scandi will be raw I imagine but as per the parameters on the run would probably bring nothing more than stratus and drizzle to the east coast and maybe a little wintriness with elevation.

Trying not to over-analyse too much, given it will change, but the deep cold pool dropping down across Scandinavia is NW Russia bound given the northern arm of the bifuricated jet over the top of the Scandi high takes energy that direction. But we do tap into the western peripherals of this cold pool.

Still, for coldies, it's better than mild zonality with wind and rain that we have this week. Will certainly feel wintry in the easterly, but it doesn't look like a convective snow shower producer off the North Sea given the lack of deep cold.

Prefer to see a long draw NEly feeding direct into the deep cold pool dropping down across Scandi from the arctic rather than the long route of modified cold air around a Scandi high which mixes with less cold air over northern Europe. Still time for changes towards this colder feed though.

Nick im sure you'll agree?!..

Id rather be viewing a weak diluted easterly incursion 7+days out.

As a vigorous beast will only be watered down!..

And exeter-met- are shouting this one on.

And the signal is eye-opening!

Im looking for gain from midweek onward-via output on this one.

Edited December 31, 2017 by tight isobar