model discussion Model output discussion - closing in on Winter

[Methuselah]

Well, one thing I will say is that I like the overall pattern that seems to be emerging; it reminds me of the late 1960s and 1970. Repeated blasts of Arctic air from the north or northwest, bringing chances of coastal snow and slider lows. Though, of course, we need to remember today's warmer SSTs!

    

[MATTWOLVES 3]

Wow...the output for once like as happened so much in the past,appears to not be backing down!

Some cracking 0z ens earlier  

I've got to be honest here...I ain't been this happy since my x missus was going through Holiday brochures the other year and said...Matt pack your bags!... wow you taking me on holiday love....No...im leaving ya!

I ain't looked back since...bliss

Edited November 18, 2021 by MATTWOLVES

[bluearmy]

24 minutes ago, jules216 said:

This is what I like to see GFS Control. Pesky Biscay low to go east,not west and the whole system then múch further east

Jules - you need an e European MOD thread !  Otherwise you’re just going to be swimming against the tide every six hours !!

[MATTWOLVES 3]

Good UKMO run to boot...absolute cracker...just noticed Marco p as tweeted that unless we get a true Block into Greenland,we will struggle to get true Arctic air in...but UKMO manages to achieve it at day 7. The potential gathers pace.

[jules216]

4 minutes ago, bluearmy said:

Jules - you need an e European MOD thread !  Otherwise you’re just going to be swimming against the tide every six hours !!

Swiming against the tide and against the -NAO, no wonder why -NAO has no correlation with cold weather here as seen by recent developments, give me Scandi high anytime, -NAO is high risk/high reward but generally favors Alps.

 

[Ali1977]

2 minutes ago, MATTWOLVES said:

Good UKMO run to boot...absolute cracker...just noticed Marco p as tweeted that unless we get a true Block into Greenland,we will struggle to get true Arctic air in...but UKMO manages to achieve it at day 7. The potential gathers pace.

I think that was yesterday’s tweet after the 12z , things still looking good though 

[SqueakheartLW]

I have posted this in the ENSO thread but decided to put it here also as I feel it may get more viewings in this model discussion thread since it appears to be quite busy in here with the potential cold spell coming

I do feel that this evolution of the ENSO situation could be quite relevant to the up coming cold spell and when you read on you'll see why I am saying this.

As to the subject of my post itself we seem to have rapidly swung from a CP La Nina to an EP La Nina in recent times as the tropical tidbits charts below show

This had got me thinking about whether there had been any years where a La Nina started out as a CP event then progressed more to an EP event as the season progressed. I was surprised to find a few example years in fact.

I have grouped them up into two types. The first are where the coldest anomalies shift east but the overall ENSO pattern remains colder than average overall throughout the featured period. The second group are ones where warmer anomalies feature mainly in either NINO 4 late on or NINO 1+2 early on or an El Nino is on the way the following year and a general warmup is shown later on.

I have included lines to show the general progression from a CP event to more of an EP event

Group 1 - Cold ENSO throughout with eastward progression of coldest anomalies

As you can see here the ENSO regions generally remain colder than average or we get to average at the very warmest

Group 2 - CP to EP Cold ENSO but with some warmer anomalies at times late on or in NINO 4 late or NINO 1+2 early

As you can see here we feature some warmer ENSO region anomalies at times

Our current monthly ENSO values and how they compare with Group 1 and Group 2

As you can see here we have a bit of Group 2 situation in the fact we had some warmer NINO 1+2 anomalies early on but these have now cooled. However this was only ENSO Neutral so you could say we also qualify for Group 1 too.

Now to compare each group to the CET anomalies of the featured years

Group 1 - Cold ENSO throughout with eastward progression of coldest anomalies

This cluster of winters contained some notable cold years such as 1878/79, 1879/80, 1916/17 and 1962/63. Here's how the anomalies averaged out and their result on the projected CET values vs the 1991-2020 average

For cold winter lovers this CP to EP La Nina or cold ENSO CP to EP is a very good signal for a colder than average winter. All months from December through to March had decent cold anomalies, especially the Januaries. If we are to keep the ENSO region cold for long enough then watch this space. We could be on for a classic cold winter.

Group 2 - CP to EP Cold ENSO but with some warmer anomalies at times late on or in NINO 4 late or NINO 1+2 early

This cluster of winters was smaller and only really contained one colder than average winter, 2008/09. Here's how the anomalies averaged out and their result on the projected CET values vs the 1991-2020 average.

For cold winter lovers this signal is bad news in general as it would seem any influence from warmer ENSO values mutes the colder signal for these winters, especially for February and March. What this means is if we want a colder winter we don't want to see an early development of an EL Nino next year or any significant warm up of any of the ENSO regions before spring at the very earliest but better still next summer to keep the warmer ENSO influence off the up coming winter.

[MATTWOLVES 3]

5 minutes ago, Ali1977 said:

I think that was yesterday’s tweet after the 12z , things still looking good though 

Cheers Ali,I'm getting ahead of myself here. But yeh,today's UKMO looks equally super.. 

 

[Methuselah]

Am I the only one on here who couldn't give two hoots about the latest NAO forecast? I mean, isn't it obvious that the right synoptics lead to a desirable NAO?

That said, the NAO is clearly a good way of assessing the synoptics of yesteryear!

Edited November 18, 2021 by Ed Stone

[Ali1977]

10 minutes ago, MATTWOLVES said:

Cheers Ali,I'm getting ahead of myself here. But yeh,today's UKMO looks equally super.. 

 

That’s also very nice. I also noted the control is still looking great at day 12.

Lots of chopping and changing, looking forward to the 12z

[Climate Man]

Just now, Ali1977 said:

That’s also very nice. I also noted the control is still looking great at day 12.

Lots of chopping and changing, looking forward to the 12z

Yep, chopping and changing is all part of the fun/interest.  However cold or not it gets, we are in for a sustained period of interesting meteorology after a lengthy period of boredom.

[Mark Smithy]

Blimey. Just seen the latest GFS output. That 6 run is quite something.

People have every right to talk this down but it must be a long long time since any of us have seen such a potently cold start to winter.

[Griff]

5 minutes ago, Mark Smithy said:

Blimey. Just seen the latest GFS output. That 6 run is quite something.

People have every right to talk this down but it must be a long long time since any of us have seen such a potently cold start to winter.

I did a quick double check, really would be something if that came off for the entire run! 

A bit nearer the 144s now compare like this... 

Obviously gfs is further ahead given the difference in run times, but ukmo has a pleasing / cleaner look as many have already commented. 

Edited November 18, 2021 by Griff

[Skullzrulerz]

9 minutes ago, Mark Smithy said:

Blimey. Just seen the latest GFS output. That 6 run is quite something.

People have every right to talk this down but it must be a long long time since any of us have seen such a potently cold start to winter.

We have to remain cautious, we have seen this all before only to be watered down.

It's something we have seem all to much in recent years.

 

[Neil Harris]

20 minutes ago, Mark Smithy said:

Blimey. Just seen the latest GFS output. That 6 run is quite something.

People have every right to talk this down but it must be a long long time since any of us have seen such a potently cold start to winter.

Think last year , the last week of November was cold. Looking back there were some frosts.. Not sure if these models show colder (I'm no expert on models)

[weirpig]

Still non the wiser in regards to the mid term  The scatter at just 192h is large with the OP right out on the mild side  A few days till the mist clears

 

[Griff]

@MATTWOLVESwe should have gone halves on that highland log cabin...

A sneaky look at the sacred ukmo mogreps. 

Certainly a short term trend. It's almost as if Scotland or the alps are better placed for cold than my 70 odd metres above sea level. 

Still, nice to sea a wintry end to autumn! 

 

[Climate Man]

20 minutes ago, Neil Harris said:

Think last year , the last week of November was cold. Looking back there were some frosts.. Not sure if these models show colder (I'm no expert on models)

There were a couple of frosts in the last week and max temps in double figures. My Midlands weather station. We are talking potentially very much colder than this.  Daytime wind chill sub zero.

Edited November 18, 2021 by Climate Man

[MATTWOLVES 3]

Good lord that's some 6z run...it keeps things cold for literally the entirety!

Now if that comes off,I may start thinking of something special so soon..but its 1 run,so feet remain grounded! 

[Polar.]

7 hours ago, knocker said:

Am I missing something here . As I see the gfs this morning, as the Atlantic high pressure does not ridge that far north, the jet is flatter and thus resulting in the very cold air just giving the UK a glancing blow. This has always  been a  knife edge scenario and it is not over yet by any means

Agree.

Edited November 18, 2021 by Polar.

[Methuselah]

Aye, the Rorschach blots look fine, @MATTWOLVES; the GEFS ensembles look okay:

    

Edited November 18, 2021 by Ed Stone

[ScottSnow]

33 minutes ago, MATTWOLVES said:

Good lord that's some 6z run...it keeps things cold for literally the entirety!

Now if that comes off,I may start thinking of something special so soon..but its 1 run,so feet remain grounded! 

It looks like we are heading in the right direction but to my eye unless you live in the north and at elevation it’s nothing to write home about.

[bluearmy]

look at the run to run variance at just day 6 on the eps mean - emphasises why some are urging caution on any detail once the cold comes in 

[sheikhy]

Just now, bluearmy said:

look at the run to run variance at just day 6 on the eps mean - emphasises why some are urging caution on any detail once the cold comes in 

Scary!!looks like a north sea/norwegian high!!!!no output has that at the moment but imagine if it ends up like that!

[knocker]

5 minutes ago, Snow White said:

It looks like we are heading in the right direction but to my eye unless you live in the north and at elevation it’s nothing to write home about.

Oh I don't know, you could have gales and plenty of rain. As  ba has said the detail next week is along way from sorted so people shoud be keeping their powder dry and keep the Prozac handy

 

Edited November 18, 2021 by knocker