Model Output Discussion - Spring Has Sprung

[TillyS]

38 minutes ago, Addicks Fan 1981 said:

I think we need to keep our eyes on the MJO as I don't think the EC46 is the right thing to be using now.   The MJO which posts later on gives a lot of clout

None of these teleconnections markers have proved reliable all winter. It begs the question for how much longer this model output discussion thread will be dominated by discussions of these teleconnections when we already have three excellent main model outputs: the GFS, the ECM, and the UKMO.

Greater focus on those three models, especially inside T168, would save a lot of misdirection.

[TillyS]

 Ali1977 It is but the GFS tends to overstate snow. The uppers are okay but the direction of impact from the north-west is slightly shaky, especially because of the long draw across the sea.

Having said that, it’s quite normal to get snow showers in March and April from such set-ups if there’s sufficient velocity to the system.

Of note, the BBC Meteo Group forecast aren’t at the moment interested. 

[Ali1977]

 TillyS What’s even more surprising is the mean for Friday morning - that’s a strong signal

[nick sussex]

I’m not a fan of cold springs and you always get the feeling it’s just rubbing salt into the wounds of coldies as the perfect winter synoptics  turn up too late .

The SSW due around the 5th March does seem to show signs of effecting the trop quite quickly .

Whether that adds up to a reminder of winter still to be determined .

A sign that things might be developing on that front is the troughing anchored to the west of the UK starts to disrupt energy se and elongates rather than just the revolving more bowling ball trough set up .

 

[MattH]

 TillyS

This post in itself is misdirection...

One failed evolution linked to previous discussions regarding the teleconnections and the likes of the GSDM and people then suggest they are not reliable, rubbish. There have been a handful of cases throughout the winter when the connections between these and the sensible weather on the surface have played out well. There's a saved post of mine from weeks back, highlighting the connections between the evolution of the GSDM and the waxing and waning of the AO through Dec and Jan, when we experienced both very good examples of +ve AO and -ve AO events. This last 'failure' is seemingly linked to a highly complex setup due to stratospheric interference and reflections - https://climateimpactcompany.com/daily-feature-introducing-a-new-index-to-help-forecast-polar-vortex-arctic-air-episodesstratospheric-downward-wave-reflection-events-2-2/ possibly, amongst other things too, but aren't worth bothering discussing.

You can't win them all...

You're right about the models mind and that includes the full suite of NWP, not just those three models, if you're looking at the short-term, then everyone should be looking at the ECM, UKMO et al.

Regards, Matt.

 

 

Edited February 27 by MattH

[MJB]

 Ali1977

JFF Control is keen on something colder into March 

[Met4Cast]

 TillyS

1 hour ago, TillyS said:

None of these teleconnections markers have proved reliable all winter. It begs the question for how much longer this model output discussion thread will be dominated by discussions of these teleconnections when we already have three excellent main model outputs: the GFS, the ECM, and the UKMO.

The only real "teleconnection" fail this winter was in January when we saw a reflective SSW event, something that's rather rare and cannot be forecasted beyond the short term, the stratosphere is a very important factor & can overrule tropospheric forcing, which is what happened (See my post in the Winter post mortem thread where I explained all of this)

Otherwise, they've been a good indicator throughout this winter in terms of broadscale patterns. What you can't do though is take the MJO in isolation like many in this thread do. Many see the MJO phase, look at the composite and expect that to be the pattern that verifies but unfortunately it's not that simple. The MJO is just one variable in the broader windflow budget and you need to look at both tropical & subtropical forcing, looking at just 1 variable will not give accurate results.

I hope the thread becomes more filled with teleconnection talk rather than less, these teleconnections drive the models, not the other way around and the more we understand them, the more accurate future forecasts will become. 

In terms of the shorter term though, yes NWP rules the roost. Teleconnections can only give broadscale indications of potential pattern changes, they cannot tell you it will snow in X location on X day. 

Edited February 27 by Met4Cast

[knocker]

Why should this thread become even more filled with teleconnections and Stratosphere talk? There are separates threads for those subjects. It is almost as if synoptic meteorology, and all the interesting complexities of that, is a no go area. Without this being addressed adequately I am not sure how punters relatively new to interpretating models can possible get to grips with it. 

Edited February 27 by knocker

[Met4Cast]

19 minutes ago, knocker said:

Why should this thread become even more filled with teleconnections and Stratosphere talk?

Because they go hand in hand with the models, they provide context to modelling which can help to understand why modelling is doing what it’s doing, I don’t see how a bit of knowledge on that is a bad thing? 

The rest of your post is a little bizarre if i’m honest, nobody has suggested synoptic modelling can’t be discussed?

[knocker]

 Met4Cast I wasn't aware that I was suggesting that knowledge in itself is a bad thing. What I was suggesting is that posting comments on teleconnections, Stratosphere/Troposphere interactions and synoptic meteorology all in the model discussion thread, is in my humble opinion operation overload and asking a lot from many punters, including myself.. And there really is no need for the separate threads in that case. I will leave it there as I realise my opinion is not welcome in here

[Met4Cast]

7 minutes ago, knocker said:

What I was suggesting is that posting comments on teleconnections, Stratosphere/Troposphere interactions and synoptic meteorology all in the model discussion thread, is in my humble opinion operation overload and asking a lot from many punters, including myself.. And there really is no need for the separate threads in that case.

I think the separate threads serve well for more prolonged conversations but I don’t see an issue with highlighting various teleconnections or the strat in this thread given the role & importance they play in the weather & the modelling that this thread is for. 

[Polar Maritime]

Let's please move on the what this thread is about, That is Model Output Discussion, Thanks all.

[Rain All Night]

16 hours ago, Rain All Night said:

12z deterministic runs, Tue 27th to Mon 4th (day 7)

It looks like a case of things getting worse before they get better... though at least these charts are a reminder that high pressure over Europe can yield, when it wants to.

12z ensemble means, Tue 27th to Tue 12th (day 15)

Similar to this morning, but with that low signal to the southwest from the 8th not quite as strong.

0z/6z deterministic runs, Tue 27th to Tue 5th (day 7)

All looking pretty much as expected up to the final day or so, when the ensemble means leave me optimistic that the GEM solution without the high over Portugal will not verify.

0z/6z ensemble means, Tue 27th to Wed 13th (day 15)

I'm liking this! It seems our fortunes may be changing for the drier around 6th March (day 8). The mean surface low does start to look a bit more iffy around 11th March perhaps, but that's way out at day 13 so we can disregard it for now.

Edited February 27 by Rain All Night

[Met4Cast]

Yesterday’s CPC MJO update suggests a return to the Indian Ocean before progression through the Maritimes as the cycle resets so further away from the typical “blocking” phases than originally anticipated, having said that the SSW early March could have some impacts on the MJO & thus forecasts are more uncertain than usual. 

Assuming this is the direction of travel though, the next surge in momentum is fairly predictable with an uptick in frictional torque followed by a return to positive mountain torque values adding westerly momentum to the atmosphere thanks to the MJO progressing eastwards.

With that in mind, it continues to seem less likely that’ll we’ll see colder patterns establishing for the UK with high pressure early March likely to be too far NE of the UK with a rather active Atlantic jet hitting that road block, it could potentially be quite wet, especially in the north & west depending on exactly where any blocking highs set up before the patter, I suspect, quickly flattens out coinciding with this next momentum push. 

I see the Met Office extended is more inline with this & indeed with my thoughts posted yesterday morning a page back.

Any blocking is a result of the recent abrupt drop in AAM tendency as westerly winds are scrubbed, i.e increasing easterly trade wind strength. 

El Niño is on very thin ice now. 

Edited February 27 by Met4Cast

[feb1991blizzard]

Met Office's verdict on snow wall bringing six inches per hour that could fall 'anywhere' - Bristol Live

WWW.BRISTOLPOST.CO.UK

---

The white stuff is expected to fall at the start of next month

[raz.org.rain]

 feb1991blizzard Reach Group, that says it all really.

[feb1991blizzard]

 raz.org.rain

Wonder how long this 6 inches an hour will go on for?, if it goes on all day, that'll be 144 inches of lying snow!

[danm]

 

[Jacob]

 feb1991blizzard at least it’s not exacta weather

[Ali1977]

 danm Fridays snow chances are increasing i think  

[andymusic]

mega reversal 10th March could well be ssw gfs 12z

[Mike Poole]

GFS 12z going with the easterly that was suggested on the clusters this morning from day 11. T264:

T312, and the cold air finally beginning to make itself felt.

 

Edited February 27 by Mike Poole

[*Stormforce~beka*]

 feb1991blizzard I'm up for it ...

[Addicks Fan 1981]

 Met4Cast wonder what the hovmoller plots are suggesting currently? I know that @Singularityis a master in that field at knowing with what they imply, but there's other people on this site who can notice things very well where that is concerned.   

 

[Frosty.]

Why is anyone still posting?.... Is it the Gfs 12z op?.... Yeah right,....give it up coldies, this winter was a joke of epic proportions!...roll on spring warmth and sun...  Yes, reverse psychology of course as i'm a die hard coldie.. . But, you know, even i know when to admit defeat!...at least we still have April!