Model Output Discussion - Into February

[blizzard81]

17 minutes ago, snowray said:

That looks pretty decent.

I know that we moan a lot about days getting longer in February, myself included, but having read a few things about winter Lore and weather history it's a month that can produce some of the most bitter winter weather. It's just that most of us today have not experienced a severe February in our lifetime. apart from the odd BFTE and then a quite rapid warm up.

 

Two very old sayings spring to mind.

As the days get longer the cold gets stronger.

and

February is short, short, but worse than a Tork. (Turk) This goes back to the time of the Ottoman Empire.

NB...Apologies if I might have bored you with my musings. Anyway, hopefully we can see further upgrades in the coming day or two which will produce a memorable February.

 

Not boring at all. Keep em coming. 

[Rob 79812010]

The 2018 BFTE was pretty amazing though! Only one in my lifetime was 87! Even colder than Feb 63!!!

[Mark wheeler]

28 minutes ago, Ali1977 said:

I think we are going cold, the NAVGEM is all over it

Oi oi . Its nailed then for sure .

[Uncertainty]

1 hour ago, feb1991blizzard said:

Quite a few going for a late feb SSW now.

in fact majority cluster with SSW at some point during run.

The @bluearmy nemesis cold spring run.

What have we said all along Feb, cold March looks as close to nailed on as can be.

Really intriguing evening of output. Virtually all output more amplified and support for the elusive scandi has jumped from virtually impossible this morning to border line likely if one were to take the output at face value. Gfs / ecm / gem / icon / navgem all flirt with the idea to varying degrees. 
 

Me? I’ve been duped by phantom scandi heights in the 8-10 so many times (7/8 don’t verify imho) that I’ll wait a while longer before believing it. But an eyebrow has most definitely been raised

[Penicuikblizzard]

49 minutes ago, Ali1977 said:

I think we are going cold, the NAVGEM is all over it

Looking like Turkey is more likely going into the freezer than we are in the UK looking at those charts 

Edited January 30, 2023 by Penicuikblizzard

[Cheshire Freeze]

1 hour ago, bluearmy said:

Yes an early final warning and undoubted wintry Easter to follow 

whilst the ec46 mean looks less than exciting, 19/26 feb has a decent cluster with a ridge to our west and trough over scandi 

and the 00z eps mean at day 15 wasn’t quite as ‘interesting’ as the 12z is. 

we still have plenty to be looking at in the 10/15 day period re possible scandi ridge developments 

It's been looking odds on for an early final warming for some time, I mentioned last week that it looks ripe for it.

CFS has been churning out run after run of Greenland blocking episodes in April and the uppers shown to be associated with these episodes have frequently touched -8 to -10!

Edited January 30, 2023 by CreweCold

[Daniel*]

2 hours ago, Stuie W said:

You can`t discredit this post, who bloody knows the current evolution.  Just wished the teleconnections NAO wise were showing a more negative trend.

Not always useful metric if there is a Scandinavian high and easterly winds the NAO is often in positive territory or neutral. 

[nick sussex]

The GFS is quite different from the Euros over southern Greenland .

It blows up low pressure which runs ne and becomes absorbed in the PV and tries to eject some shortwave energy se at the same time .

The Euros take that low east .

[BLAST FROM THE PAST]

32 minutes ago, Uncertainty said:

What have we said all along Feb, cold March looks as close to nailed on as can be.

Really intriguing evening of output. Virtually all output more amplified and support for the elusive scandi has jumped from virtually impossible this morning to border line likely if one were to take the output at face value. Gfs / ecm / gem / icon / navgem all flirt with the idea to varying degrees. 
 

Me? I’ve been duped by phantom scandi heights in the 8-10 so many times (7/8 don’t verify imho) that I’ll wait a while longer before believing it. But an eyebrow has most definitely been raised

You look at my outlook, Record challenging cold for March.  High confidence of it happening.  There be will solar induced SSWarmings…which may impact late Feb but will definitely bring a ‘March of note’

 

BFTP

Edited January 30, 2023 by BLAST FROM THE PAST

[Rain All Night]

4 minutes ago, CreweCold said:

It's been looking odds on for an early final warming for some time, I mentioned last week that it looks ripe for it.

CFS has been churning out run after run of Greenland blocking episodes in April and the uppers shown to be associated with these episodes have frequently touched -8 to -10!

I have been seeing this term 'early final warning' - I'm assuming that it's usual for there to be an (possibly SSW-like?) stratospheric warming event each year when the polar night recedes and the northern hemisphere starts to warm from which the SPV isn't going to recover until the next autumn, and that an 'early' final warming might make this event more dramatic and SSW-like and create a high risk of a cold spring following?

[Cheshire Freeze]

Just now, RainAllNight said:

I have been seeing this term 'early final warning' - I'm assuming that it's usual for there to be an (possibly SSW-like?) stratospheric warming event each year when the polar night recedes and the northern hemisphere starts to warm from which the SPV isn't going to recover until the next autumn, and that an 'early' final warming might make this event more dramatic and SSW-like and create a high risk of a cold spring following?

Bingo

[Cambrian]

Best looking cold run of the day for me (other than my outstandingly athletic dash to the log shed earlier this evening) was the 12z ECM control run all the way out to day 15 - shows how to get from dull, breezy and mild to UK / Ireland high by around day 7 / 8 to something very interesting in week 2. The control incidentally was a very good match for the op through to day 10. 

 

A fascinating evolution, resulting in 4 or 5 days of low uppers from around day 9 to day 14 (here for Birmingham, the thicker blue line), even managing to finish up with a classic Atlantic disruption setup and hints of a battleground scenario as systems approach from the southwest towards the end. Neatly sorts out that northern arm of the jet stream too!

 

A long way off of course, so all good fun for now but a bit of a buzz all the same to see a good number of similarly interesting op and control runs cropping up. 

[feb1991blizzard]

Final SSW average date is well into spring, however, there is more chance of an earlier date if you haven't had a major midwinter SSW, i would say looking at the data if we have an SSW, there's a chance of it not being a final warming if we had one in late Feb, but the further you go into spring there's less chance of u-wind returning to positive again.

Stratospheric Final Warmings fall into two categories with different evolution over the course of the year

WWW.NATURE.COM

---

The transition of the northern stratospheric circulation from winter to summer comes in two flavours, a smooth late one governed by radiation or an abrupt, early transition...

also, the earlier the date, the higher the polar temp anomaly so more likely to be abrupt and impactful.

[Mike Poole]

2 minutes ago, feb1991blizzard said:

Final SSW average date is well into spring, however, there is more chance of an earlier date if you haven't had a major midwinter SSW, i would say looking at the data if we have an SSW, there's a chance of it not being a final warming if we had one in late Feb, but the further you go into spring there's less chance of u-wind returning to positive again.

Yes.  It’s a certainty, I believe - by definition, a SSW has to be followed by a reversion to westerlies at 10hPa, 60N.  

Otherwise it is the final warming!

So that does make for two sorts, one by mechanisms that would otherwise be called a SSW - and have a similar effect.  And one where the vortex just peters out into the spring…

[Gowon]

17 minutes ago, nick sussex said:

The GFS is quite different from the Euros over southern Greenland .

It blows up low pressure which runs ne and becomes absorbed in the PV and tries to eject some shortwave energy se at the same time .

The Euros take that low east .

Slightly better than it's 12h run at day 6

Edited January 30, 2023 by Gowon

[Rain All Night]

3 minutes ago, Gowon said:

Slightly better than it's 12h run at day 6

Interesting wall running through us!

14 minutes ago, CreweCold said:

Bingo

I'm going to go for broke here - is the 'stratospheric final warming' also the reason for northerly and easterly winds at the surface being more prevalent in April and May than in any other months?

[Cheshire Freeze]

2 minutes ago, RainAllNight said:

Interesting wall running through us!

I'm going to go for broke here - is the 'stratospheric final warming' also the reason for northerly and easterly winds at the surface being more prevalent in April and May than in any other months?

It's part of it yes.

If you can get an early enough final warming, the cold that has 'bottled up' throughout winter has to drain somewhere into the mid latitudes. Obviously this is moderated by surface heating (more and more the further into spring we go) but we can still get some falls of snow and some notable cold comparable to the time of year.

[Gowon]

3 minutes ago, RainAllNight said:

Interesting wall running through us!

I'm going to go for broke here - is the 'stratospheric final warming' also the reason for northerly and easterly winds at the surface being more prevalent in April and May than in any other months?

That's an impressive block over us all the way up through the arctic at 192 - the blob struggles to get past it

[Lukesluckybunch]

Just now, Gowon said:

That's an impressive block over us all the way up through the arctic at 192 - the blob struggles to get past it

there is..but its too far east isnt it?you can already see the atlantic is trying to come in

[Gowon]

Just now, Lukesluckybunch said:

there is..but its too far east isnt it?you can already see the atlantic is trying to come in

It is this time

[nobble]

44 minutes ago, CreweCold said:

It's been looking odds on for an early final warming for some time, I mentioned last week that it looks ripe for it.

CFS has been churning out run after run of Greenland blocking episodes in April and the uppers shown to be associated with these episodes have frequently touched -8 to -10!

About time we had an April to remember

[Lukesluckybunch]

4 minutes ago, Gowon said:

It is this time

i am really no expert,but i like to use iceland as a marker if we can keep the pv to the west iceland then we may see a successful build if heights to the northeast,if it comes further east there is normally to much energy over riding it..and its a real struggle for the high to build properly!

Edited January 30, 2023 by Lukesluckybunch
adding

[Don]

19 minutes ago, Lukesluckybunch said:

there is..but its too far east isnt it?you can already see the atlantic is trying to come in

Are the models trying to bring in cold too early when in reality it will more likely be later February if it does arrive?!

Edited January 30, 2023 by Don

[Daniel*]

Some cold runs appearing in ECM ens. I suspect the number will continue to grow in coming days. I think operational runs have been more useful in this instance in leading the way. Credit I think to GFS which first toyed with Scandi height rises in FI. 

Edited January 30, 2023 by Daniel*

[damianslaw]

1 hour ago, Uncertainty said:

What have we said all along Feb, cold March looks as close to nailed on as can be.

Really intriguing evening of output. Virtually all output more amplified and support for the elusive scandi has jumped from virtually impossible this morning to border line likely if one were to take the output at face value. Gfs / ecm / gem / icon / navgem all flirt with the idea to varying degrees. 
 

Me? I’ve been duped by phantom scandi heights in the 8-10 so many times (7/8 don’t verify imho) that I’ll wait a while longer before believing it. But an eyebrow has most definitely been raised

Yes interesting to see ECM flirting with idea of significant height rises to our NE, but still at the 10 day range. GFS continues to also play around. The Polar Vortex does look very strong to the NW, but has it reached its maximum strength I wonder, as we move through February as usually the case will lose energy. If this was early in the winter, then chances of it disappating less likely, yet this winter it hasn't managed to fire on full gear - hence lack of stormy atlantic conditions.

Always used to think and still do that scandi highs become more likely in the latter part of winter, Feb and March, Greenland highs earlier in the winter - generally because the atlantic typically quietens down, however, as last feb proved, its not always the case and I wonder whether it is more to do with stirrings in the Strat and warming, which initially produce bursts of westerlies which then blow themselves out.

 

Edited January 30, 2023 by damianslaw