Model output discussion - Post SSW - Will it turn cold?

[bluearmy]

13 minutes ago, frosty ground said:

What time frame are you talking about?

The overall pattern is pretty much the same, and surely beyond 5 days that's' all we should be looking at?

I’m referring to the 6/8 day period as ops become useless re any detail at all beyond that ! Yes the broad scale pattern is well advertised (trough/ridge/trough) but detail at day 5/8 which we would hope to have a decent handle on at the moment - we don’t other than a MLB which will go north but when ???

if we limit ourselves to T120 then this place will be pretty dull !

[Astral Goat Juice]

11 minutes ago, bobbydog said:

well if all this winter ends up giving us is around 3 solid days of persistent heavy snow and blizzards,

i suppose it'll have to do....

Good eye candy but that's all it is.

Only two days ago was it showing cold and snow for 22nd. Now it's the 26th. 

What will it be tomorrow? Always chasing F1.

[weirpig]

control  faster evolution  battleground uk  192

[karlos1983]

Control run prefers the impatient route, here here i say

[frosty ground]

A range of options at day 5 

[frosty ground]

Just now, karlos1983 said:

Control run prefers the impatient route, here here i say

Look at number 10 (already posted) I think thats the fastest route. (day 6)

[Scandinavian High.]

I think trend now is next week will start milder then as we progress later part next week turns colder from east with snow showers becoming more widespread ..

[weirpig]

-10  around this time next week

[Derecho]

5 minutes ago, frosty ground said:

A range of options at day 5 

Yup there seems to be a subtle shift to bring in the cold earlier with some ensemble members.

Hopefully the start of a trend as I don't want to watch things go round in circles in F1 when we reach March 

Edited February 14, 2018 by Quicksilver1989

[karlos1983]

here's the panel for D7

[bobbydog]

3 minutes ago, Astral Goat Juice said:

Good eye candy but that's all it is.

Only two days ago was it showing cold and snow for 22nd. Now it's the 26th. 

What will it be tomorrow? Always chasing F1.

actually, the cold (according to this run) arrives on the 23rd.

the details can change at that range, it could be sooner or it could be later. those charts i posted were from the midst of this (potential...) cold spell.

in reality, the 24th- 26th would be about right to see any significant weather event and has been the case for some time. from a model watching point of view, we've seen a few options where the cold arrives earlier. 

people need to remember- this is not a forecasting thread. its a bunch of weather enthusiasts trying to pre-empt what the next forecast might say, using the latest information available to us. everyone is entitled to a punt at what they think might happen and we will frequently be wrong. sometimes though, we might be right....

[Man With Beard]

With longer term trends seeming a bit scambled apart for the principle of northern blocking somewhere ... I'm back to analysing the short-term this morning. 

The volatility on the models at even D5/D6 means lots of different ways forward are possible for D6/D7/D8. Last night I was wondering if we might get a negative tilt on the Atlantic low today. Actually the output has gone the other way this morning. But another thing I'm looking at is how the Arctic High might interact with Scandinavia:

  

The ECM in particular is fairly close to developing an Arctic High / Scandi High link-up. 

The GEFS control run develops it that little bit more.

This leads to a block forming that the Atlantic hits rather than overridding:

  

It's all on the table IMO

Having called the long-term trends "scrambled", though, I note that 1030mb Scandi High for the 24th February continues to count down - I started tracking it last Friday at T360ish - it's now down to T240:

 

 

Edited February 14, 2018 by Man With Beard

[Derecho]

2 minutes ago, Seasonality said:

Hopefully we'll have 'F1' snow. 

 

Yup solid support for a Greenland high in the ensembles still at least upto T192. Lets hope the wheels don't come off for this cold spell...

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Steady as she goes 

[Ali1977]

Mean for T300, that’s not bad is it ?

[frosty ground]

Quick return to cold is supported by 3 out of the 20 runs. 

[Glacier Point]

GEFS (as per EPS) still gunning for a monster ridge, initially to our N then across Greenland. Transition seems to be around day 9 or 10.

Not convinced over any significant westward transfer of that blocking structure (remember how many times models have failed to pick up bits of residual trop vortex over the Canadian sector). All of which leaves us with high chance of cold + trough signal. Hmmmm

Edited February 14, 2018 by Glacier Point

[Snowy Hibbo]

While some are using Niña composites, and drawing trends to a Niña base state, here and the specialist threads, plus Twitter, etc, it is important to point out that we are slowly leaving Niña. And the +AAM has shown us that the Niña base state is moving away, and we are heading to a more neutral state ENSO wise. While MJO driven, this in itself is going to be very important in the coming month. Are we going to see another +AAM orbit soon (end of Feb/early March)? Are we even going to go to P2&3 GWO? You can't always follow GEFS and the NWP models, you have to think outside of the box, and move with the times. Potential for GWO effects into Spring will be important for setting the stones into place for the UK summer, and ultimately next winter. But let's think less big, and think about the now. A little summary....

MJO is now apparently moving out of it's P7 stall. GEFS and GEPS want a continued stall, and weakening into COD, bypassing any P8 progression. EPS and JMA want a P8 and P1 progression slowly weakening to the COD. Interesting to see which one is successful, currently GEFS is one up, with it's correct prediction of a strong MJO signal stall in P7.

MT is currently slightly negative/mostly neutral, with an EAMT increase in difference with the trend over the past week, which saw a large negative tendency in the MT. This is causing a movement towards GWO Phase 8, as predicted.

(Latest GWO chart: 13th Feb)

With the Nina influence clearly waning, maybe we won't see a proper -AAM phase. A slower lead from FT, may be indicating a lesser -AAM stage, and a quicker return to +AAM territory. But for the interim, the SSW impacts should out-muscle the effects of the GWO for the time being, but the GWO is an important consideration going into March.

What that means for the UK, is a trickier task to point out, and I'll leave that to more regional members here. The SSW is a clear sign of the times, but what lurks beneath will point to the long term. Whatever that means to the reader, I will wonder. But for me, a variety of NWP and teleconnections is the way to go. Linking the two, and asking the big questions about the effects on each other is what it's all about. 

Edited February 14, 2018 by Snowy Hibbo

[Seasonality]

2 minutes ago, Ali1977 said:

Mean for T300, that’s not bad is it ?

Its pretty good. Check the postage stamps for the same time, so many cold options!

[karlos1983]

some pretty cold members in the ECM ens, also some milder ones but nowhere near outweighing the colder options.

The real spread still starts around the 19th/20th, so this is far from done yet I feel. 

Edited February 14, 2018 by karlos1983

[Met4Cast]

Probably one of the best EC ENS yet

A massive cluster of colder options on there, a few milder ensembles skewing the mean a little but over all, positive. 

Is anyone able to see the clusters? I'm just getting blank images when I try and it only seems to be showing yesterdays 12z

[Glacier Point]

7 minutes ago, Snowy Hibbo said:

While some are using Niña composites, and drawing trends to a Niña base state, here and the specialist threads, plus Twitter, etc, it is important to point out that we are slowly leaving Niña. And the +AAM has shown us that the Niña base state is moving away, and we are heading to a more neutral state ENSO wise. While MJO driven, this in itself is going to be very important in the coming month. Are we going to see another +AAM orbit soon (end of Feb/early March)? Are we even going to go to P2&3 GWO? You can't always follow GEFS and the NWP models, you have to think outside of the box, and move with the times. Potential for GWO effects into Spring will be important for setting the stones into place for the UK summer, and ultimately next winter. But let's think less big, and think about the now. A little summary....

MJO is now apparently moving out of it's P7 stall. GEFS and GEPS want a continued stall, and weakening into COD, bypassing any P8 progression. EPS and JMA want a P8 and P1 progression slowly weakening to the COD. Interesting to see which one is successful, currently GEFS is one up, with it's correct prediction of a strong MJO signal stall in P7.

MT is currently slightly negative/mostly neutral, with an EAMT increase in difference with the trend over the past week, which saw a large negative tendency in the MT. This is causing a movement towards GWO Phase 8, as predicted.

(Latest GWO chart: 13th Feb)

With the Nina influence clearly waning, maybe we won't see a proper -AAM phase. A slower lead from FT, may be indicating a lesser -AAM stage, and a quicker return to +AAM territory. But for the interim, the SSW impacts should out-muscle the effects of the GWO for the time being, but the GWO is an important consideration going into March.

What that means for the UK, is a trickier task to point out, and I'll leave that to more regional members here. The SSW is a clear sign of the times, but what lurks beneath will point to the long term. Whatever that means to the reader, I will wonder. But for me, a variety of NWP and teleconnections is the way to go. Linking the two, and asking the big questions about the effects on each other is what it's all about. 

Tropical forcing will get impacted by the strat warming - most likely will get suppressed. Additionally, we have the convective coupling moving towards the far western Indian Ocean, negative frictional torque territory. Put the two together, and the engine house for aam will go into slow speed. We've also been in a solid Nina state for some period, which will have imprinted on the atmosphere. So some reduction in overall aam and negative tendency look the best place to look. I wouldn't go for a big -AAM target, maybe -1SD max given likely westerly additions through 30N-40N.

Interestingly, the likely strat impacts in the high latitudes are best expressed through tropical analogues for African and West Indian Ocean convective centres. Some sense of choreography there ?

Edited February 14, 2018 by Glacier Point

[weirpig]

6 minutes ago, karlos1983 said:

some pretty cold members in the ECM ens, also some milder ones but nowhere near outweighing the colder options.

The real spread still starts around the 19th/20th, so this is far from done yet I feel. 

same with the GEFS   big difference between two groups around that date

Edited February 14, 2018 by weirpig

[karlos1983]

6 minutes ago, Daniel Smith said:

Probably one of the best EC ENS yet

A massive cluster of colder options on there, a few milder ensembles skewing the mean a little but over all, positive. 

Is anyone able to see the clusters? I'm just getting blank images when I try and it only seems to be showing yesterdays 12z

D7 & D10

Remove they are well out of date... 

 

Edited February 14, 2018 by karlos1983

[Man With Beard]

4 minutes ago, Daniel Smith said:

Probably one of the best EC ENS yet

A massive cluster of colder options on there, a few milder ensembles skewing the mean a little but over all, positive. 

Is anyone able to see the clusters? I'm just getting blank images when I try and it only seems to be showing yesterdays 12z

Seems to be having trouble updating at brunnur.vedur.is. Last night was a couple of hours late