model discussion Model output discussion - the final third of Autumn

[damianslaw]

23 minutes ago, mb018538 said:

On the whole, a fairly strong Nina event like we're seeing develop again just disrupts the MJO cycle and it's influence. Cooler Pacific waters just kill it off before it can propagate further east. 

Did we not have a similar la Nina last year. Seem to remember MJO didn't quite play ball but we still has a couple of cold spells prior to the effects of SSW.

[mb018538]

11 minutes ago, damianslaw said:

Did we not have a similar la Nina last year. Seem to remember MJO didn't quite play ball but we still has a couple of cold spells prior to the effects of SSW.

We did - and like a lot of teleconnections it's not a silver bullet or magic formula. I think it's role and global weather link is so complicated that it's still not fully understood, hence we can get all types of weather rather than a definitive x = y outcome. We can still clearly get cold weather here with the MJO suppressed and not active.

I just love reading and learning about it all, it's fascinating! 

Edited November 4, 2021 by mb018538

[jules216]

50 minutes ago, mb018538 said:

On the whole, a fairly strong Nina event like we're seeing develop again just disrupts the MJO cycle and it's influence. Cooler Pacific waters just kill it off before it can propagate further east. 

May need more analysis on this one as I have experienced very snowy moderate La Ninas in past in central Europe, on the other hand also endless high pressure El Ninos when Pacific shouldnt have been hostile. There is lot more to it, but cant stress enough how important are 2 things : 1. Timing 2. State of the atmosphere during onset of a Rossby wave train reaching Europe.

Examples?

April 2018 and 2021. In both cases MJO spent a lot of time in phase 7. In first case it only enhanced the existing warm pattern resulting in warmest April on record here in Slovakia, in 2021 it enhanced/cemented the pre existing blocking that resulted in coldest spring since 1997.

So the base state is as important as anything.

[damianslaw]

Just now, jules216 said:

May need more analysis on this one as I have experienced very snowy moderate La Ninas in past in central Europe, on the other hand also endless high pressure El Ninos when Pacific shouldnt have been hostile. There is lot more to it, but cant stress enough how important are 2 things : 1. Timing 2. State of the atmosphere during onset of a Rossby wave train reaching Europe.

Examples?

April 2018 and 2021. In both cases MJO spent a lot of time in phase 7. In first case it only enhanced the existing warm pattern resulting in warmest April on record here in Slovakia, in 2021 it enhanced/cemented the pre existing blocking that resulted in coldest spring since 1997.

So the base state is as important as anything.

The weather is complex if it wasn't this forum thread wouldn't exist! There is no magic formula to it! 

[Stu_London]

Models seem to be trending a bit more zonal in the medium term. TS Wanda looks like giving the +NAO a bit of shot in the arm next week.

Not full on blow-torch and not a particular worry at this time of year unless the pattern becomes really embedded. 

[damianslaw]

1 hour ago, Stu_London said:

Models seem to be trending a bit more zonal in the medium term. TS Wanda looks like giving the +NAO a bit of shot in the arm next week.

Not full on blow-torch and not a particular worry at this time of year unless the pattern becomes really embedded. 

Hope Wanda wanders off quickly then!

Edited November 4, 2021 by damianslaw

[Anthony Burden]

Met office on their extended forecast untill mid month talking wintery showers on high ground

and possibly low ground around middle of month.Then firming up on cold weather with wintery showers

from mid month to beginning of December.Very interesting forecast are we looking at northern blocking to

our west/northwest and low pressure to east/northeast influencing the unsettled cold theme.

[booferking]

Starting to look very blocked on the last gefs update @264hr.

Ukmo is without interest @144hr wedge of heights forming compared to gfs op.

[damianslaw]

Much more amplified set up from GFS 12z.. euro heights migrate eastwards pulling up a southerly but at the same time elongation the trough to the west on a north- south axis which has domino effect raising heights to the NW.. end result trough moves through and we pull in a much colder feed by 16th..this ties in with met office outlook. Thereafter quite a complex set up.. all eyes on where euro high parks itself.. 

[Cambrian]

12z UKMO operational extended for 168h looks like it’s building a high right up the middle of the Atlantic to Greenland.

[Ali1977]

7 minutes ago, Cambrian said:

12z UKMO operational extended for 168h looks like it’s building a high right up the middle of the Atlantic to Greenland.

That’s way different to the GFS, but if the ECM back it we are game on I’d say!! 

[booferking]

9 minutes ago, Cambrian said:

12z UKMO operational extended for 168h looks like it’s building a high right up the middle of the Atlantic to Greenland.

That's exactly what i thought would happen after 144hr didn't even know you could get 168hr chart on wetterzentrale.

[Ali1977]

24 minutes ago, Ali1977 said:

That’s way different to the GFS, but if the ECM back it we are game on I’d say!! 

ECM backs the GFS, back to FI chasing again

[Mike Poole]

ECM disappointing towards the end, but JMA T264 and also GEM T240 perhaps showing the kind of evolution that might persuade you, and indeed the UKMO, to predict a colder period after mid month:

JMA has the stronger ridge into Greenland (although it is a day later) GEM has the trough into Europe.  All this is some way out, so there could well be big upgrades or downgrades, but it is a good signal to see.

[Ali1977]

8 minutes ago, Mike Poole said:

ECM disappointing towards the end, but JMA T264 and also GEM T240 perhaps showing the kind of evolution that might persuade you, and indeed the UKMO, to predict a colder period after mid month:

JMA has the stronger ridge into Greenland (although it is a day later) GEM has the trough into Europe.  All this is some way out, so there could well be big upgrades or downgrades, but it is a good signal to see.

You missed the mighty NAVGEM, looks good to me.

[Mike Poole]

2 minutes ago, Ali1977 said:

You missed the mighty NAVGEM, looks good to me.

Not for me, that one!  Far too early at T180 to see where that’s going longer term!  I think the period of potential interest is still day 11-12.

[jules216]

1 hour ago, Ali1977 said:

That’s way different to the GFS, but if the ECM back it we are game on I’d say!! 

How is this a good chart with that pattern to the east?

[Mike Poole]

ECM clusters and given the timeframe of interest is >T240, here’s the T264+ cluster, and we want cluster 3, 15 members so it is reasonably representative:

Blocking on all of them, no surprise as a meridional pattern has prevailed for months, it is a question of where.  

[booferking]

3 minutes ago, jules216 said:

How is this a good chart with that pattern to the east?

What a high in Atlantic extending into Greenland winds turning Northerly for UK/IRE while a jet running NW/SE into Europe lower the pressure there over time?

Where not looking for narnia outcome in early November were looking at what the metoffice is hinting at in there extended forecast with the picture improving as we move on through late November.

[jules216]

30 minutes ago, booferking said:

What a high in Atlantic extending into Greenland winds turning Northerly for UK/IRE while a jet running NW/SE into Europe lower the pressure there over time?

Where not looking for narnia outcome in early November were looking at what the metoffice is hinting at in there extended forecast with the picture improving as we move on through late November.

On this chart down the line  I see west based -NAO which in turn only reinforces the Euro high which in turn augments any cold potential in 2-3 weeks time at least. I admire the endless optimism though.

[MATTWOLVES 3]

The blocking signal is there again around mid month on tonight's EC46 anomalies...and dare I say it some early signs of Blocking towards our NW as we enter December also...For me we ain't looking at any kind of raging zonal flow at all!

Perhaps early signs of a more seasonal start to early winter.. Beyond that....who knows...but as ever,always an exciting period in the run up to Xmas.. 

So my checklist next month is

1.. Get the shopping done early.

2...Dont invite the in laws for Xmas Dinner

3...Check the latest model runs for cold potential!

4...And finally hopefully play in the snow!

Perhaps John Lewis can arrange all of this for me..

Have a pleasant Guy Falkes evening and Weekend ..

[sheikhy]

19 minutes ago, MATTWOLVES said:

The blocking signal is there again around mid month on tonight's EC46 anomalies...and dare I say it some early signs of Blocking towards our NW as we enter December also...For me we ain't looking at any kind of raging zonal flow at all!

Perhaps early signs of a more seasonal start to early winter.. Beyond that....who knows...but as ever,always an exciting period in the run up to Xmas.. 

So my checklist next month is

1.. Get the shopping done early.

2...Dont invite the in laws for Xmas Dinner

3...Check the latest model runs for cold potential!

4...And finally hopefully play in the snow!

Perhaps John Lewis can arrange all of this for me..

Have a pleasant Guy Falkes evening and Weekend ..

Seems a very good update mate!!high to the west and cold northerlies for second half of november into december!!and even if high ends up over us could be even colder with some serious frosts around!!will defo take this update❄!!

[ICE COLD]

Big change from the GFS 18z  at day 7 

18z gfs

 

12z gfs 

Edited November 4, 2021 by ICE COLD

[Griff]

32 minutes ago, MATTWOLVES said:

The blocking signal is there again around mid month on tonight's EC46 anomalies...and dare I say it some early signs of Blocking towards our NW as we enter December also...For me we ain't looking at any kind of raging zonal flow at all!

Perhaps early signs of a more seasonal start to early winter.. Beyond that....who knows...but as ever,always an exciting period in the run up to Xmas.. 

So my checklist next month is

1.. Get the shopping done early.

2...Dont invite the in laws for Xmas Dinner

3...Check the latest model runs for cold potential!

4...And finally hopefully play in the snow!

Perhaps John Lewis can arrange all of this for me..

Have a pleasant Guy Falkes evening and Weekend ..

Pub run must be listening, as it wants to get in on the drama... 

Next Friday on the latest vs the previous...

Edit: great minds... @ICE COLD

Edited November 4, 2021 by Griff

[Griff]

Followed by something in the tabloids about a weather bomb,  

Goodnight!