Model Output Discussion - mid Autumn

[Bats32]

Lovely set of ECM ensemble's this morning for here. Bit worried about the phasing on the 0zs but this looks great 

[sheikhy]

Just now, Bats32 said:

Lovely set of ECM ensemble's this morning for here. Bit worried about the phasing on the 0zs but this looks great 

Could you post leicesters if possible mate?!!!

[Bats32]

1 minute ago, sheikhy said:

Could you post leicesters if possible mate?!!!

 

[ItNeverSnowsInWindsor]

Snow row still looks on the low side for London for this initial cold spell next week.

[Malarky]

2 minutes ago, Bats32 said:

So tight it looks like you posted Glasgow twice, only you didn’t

[TSNWK]

I’m probably guilty of the phasing overload this morning… sorry gang just how it looks thought we had got past all that yesterday but this mornings theme is more complications and risk with getting substantial cold and longevity in…

greenland heights are less apararnt this morning.. so be looking for phasing trend to drop away today and Greenland heights to power up back…

off for nice sub zero walk in the sunshine…

 

[Battleground Snow]

8 minutes ago, sheikhy said:

Jheeez the ecm mean!!!!all the way to the end greenland high and cold snowy trough over and just to the east of us!!we are literally walking into a cold and potentially spellof weather with no issues!!thats not normal lol!!!!its too easy!!!

Indeed, woke up to -3 here already, 

ECM control keeps it going past day 10

[Howie]

9 minutes ago, Kentspur said:

ECM ensembles for London

Wow very tight clustering!

[Kentspur]

That lasted long several "phasing" word replies since can I mention Stockholm?

Edited November 25, 2023 by Kentspur

[matty40s]

2 minutes ago, Kentspur said:

That lasted long several "phasing" word replies since can I mention Stockholm?

Why would you want to mention Stokholm??

[Fergpfc]

17 hours ago, MATTWOLVES 3 said:

After glancing the 6z ens...the thing that smacks me round the face is the fact that 1...so many have a disorganised PV and 2...and a big one,is the fact we don't seem too be seeing that strong Azores high killing things from the South! So many  have lower heights around the med...Now this is a big plus as we all know it ranks as one of the best for being a pure Winter killer.

Some how this time around things seem aligned differently to what we normally end up with. Then we have the fact that so many times over recent months that patterns have become stuck and very slow moving.

Early days yes but I like the way things are coming together,especially as we had no real forcing to get this upcoming cold spell going! Perhaps micro scale variables closer to home allowed for certain drivers to become muted. And I feel we are entering unknown territory to the point that the background drivers could be having a much harder time of working out where we are going.

Background drivers usually influence NWP..but there's a chance with other variables rearing there heads that sometimes....and perhaps these will become more frequent,that they may at times lose there way!

So never give up hope regardless of the main factors not being favourable.

PS..And you know what really annoys me folks? Having hands that are too big for you phones keypad

News just in.

Risk of significant snow and the cold theme continues...There are signs that eventually the Atlantic will try and breakthrough but this is far from certain..and that would bring the risk of further snow! That's from the updated met text...lots going on and lots to be excited about.

 

Hi Matt just want to thank you and so many others on here that contribute to the fantastic forum the wife is writing this for me as I have the same problem of trying to write on the phone due to severe arthritis in my hand and fingers from too many years bricklaying. I'm sure some of you have noticed me kicking a like which is the best I can do unfortunately to join in with the conversation but once again thank you to you all. I'm old enough to remember many snowy times down here on the south coast and I really feel that this winter is going to bring back some fantastic memories. Good luck to you all north south east and west

[sheikhy]

7 minutes ago, Battleground Snow said:

Indeed, woke up to -3 here already, 

ECM control keeps it going past day 10

-3 here aswell!!!

[DIS1970]

4 minutes ago, sheikhy said:

-3 here aswell!!!

Snap, snowfall is borderline, depending on it's intensity.

Edited November 25, 2023 by DIS1970

[Mike Poole]

ECM clusters this morning, starting with T120-T168:

Not really much difference here between these two!

T192-T240:

Cluster 1 maintains the -NAO, 21 members, this one perhaps not well represented by the morning op runs, which have tended to be more like clusters 2 or 3 which focus blocking around Greenand and more to an Atlantic ridge regime.

T264+

There has previously been no clear signal in this timeframe, but now I think there is a suggestive signal - for extending the cold.  Cluster 1 maintains strong heights over Greenland and the north more generally out to day 15, and cluster 4 moves northern blocking towards Scandi. 

[iceman1991]

8 minutes ago, Mike Poole said:

ECM clusters this morning, starting with T120-T168:

Not really much difference here between these two!

T192-T240:

Cluster 1 maintains the -NAO, 21 members, this one perhaps not well represented by the morning op runs, which have tended to be more like clusters 2 or 3 which focus blocking around Greenand and more to an Atlantic ridge regime.

T264+

There has previously been no clear signal in this timeframe, but now I think there is a suggestive signal - for extending the cold.  Cluster 1 maintains strong heights over Greenland and the north more generally out to day 15, and cluster 4 moves northern blocking towards Scandi. 

Wow  

[weathergeek]

20 minutes ago, Fergpfc said:

Hi Matt just want to thank you and so many others on here that contribute to the fantastic forum the wife is writing this for me as I have the same problem of trying to write on the phone due to severe arthritis in my hand and fingers from too many years bricklaying. I'm sure some of you have noticed me kicking a like which is the best I can do unfortunately to join in with the conversation but once again thank you to you all. I'm old enough to remember many snowy times down here on the south coast and I really feel that this winter is going to bring back some fantastic memories. Good luck to you all north south east and west

Hi just wanted to mention that maybe you could try using a stylus pen for your phone keyboard or maybe even a 'speech to text' function, if your phone has that? Or getting a phone that does (new Xmas pressie?!) 'Speech to text' can have frustrating issues sometimes but you could try writing them in a separate document, giving you the chance to edit any odd bits and then copy and paste into a forum reply!! Good luck!!

(PS - Mods, sorry its not weather related but as there could be a few on here with similar issues, I just wanted to offer some advice as it would be a shame to hear less from these experienced members!!)

[Catacol]

11 hours ago, snowking said:

Well I’ve stayed relatively quiet for the last few days, mostly owing to not yet seeing too much in the way of excitement with regards to large scale, lowland snowfall. If I were living in the northern half of the Uk, particularly with some elevation, then I would be feeling much more optimistic. But certainly for the next 5-7 days I suspect there will be a lot of marginality as we see our relatively cool airmass interact with our very positive SST profiles around the UK. My suspicion is that we are just that one week too early, and places further south may well be reliant on some nocturnal cooling to aid dew points and wet bulb temperatures in supporting snowfall.

That said, the longer we can lock this pattern in for, the more we should be able to draw that cold pool in from the NE, as per some of the commentary in here this afternoon, let’s just hope for a nice clean transition next week with the broad upper trough.

 

It is also of course worth bearing in mind at this stage that things have been very much tropospherically driven. Even a major deceleration in the stratospheric zonal winds, let alone a full blown reversal, could basically result in a big shake up of the tropospheric order (assuming a downwelling) - think of it like a game of blackjack. We’ve already been dealt a hand of 18 by the troposphere. Do we want to stick, or do we twist with the stratosphere and hope for a 21. 
 

Lots of high risk, high reward stakes both shorter and longer term incoming.

Top post. Agree on the early days of this probably being on the wrong side of marginal, agree that strat developments could shake it up. What is different this year to many others is the strong early warming on the canadian side and I see no sign of that relenting. The north pacific is featuring one low pressure system after another at the moment. While an SSW would be a risk in shaking things up the wrong way I wonder if the risk is quite so high if the vortex is planted more over Siberia than Canada. We are several weeks away from this being relevant probably, but for now I hope the warm air assault being modelled up through the strat on the canadian side continues. Extended GFS modelling has been quite consistent on a monster high developing through Canada and Greenland as a result of north pacific impacts.

 

Vortex through the levels all being nudged onto the Scandy/Russian side

 

And got to agree with the last sentence big time. Winter weather is always high risk in terms of nailing down sustained cold, but the rewards from the current pattern could be very significant. I can't quite believe the pattern is developing this way on the back of a modest pacific wave. 

[bluearmy]

2 hours ago, Nick F said:

Another EC det blocked and cold through to day 10. The T850s don't look particularly cold, as in will produce convective wintry showers, but imagine if the flow is slack the cold will build at the surface.

Hard to pin down features that may bring some snow at the moment, but looks like the Azores low will not be a player, rather a low dropping south over Ireland before heading east close to the south mid-to-late week could bring some precipitation, perhaps wintry, to the west and south. Also low pressure over the North Sea could bring some wintry precip to more eastern areas later in week.

As you say, the  Azores low has gone from our concerns. But the phasing of the scandi and griceland low heights looks favoured to occur more south of Iceland today the further south this phasing gets probably the better for cold advection as it means it’s delayed and allows the sceuro trough to extend more across the U.K. before the Atlantic influence becomes involved and mixes some of the colder uppers out. 
the ec probably the best for uppers this morning with some of the ops (well gfs) not v good.  The period late wed to early fri is where we will likely see the first opportunity for any widespread precip with cold enough air for snowfall. currently the modelling not settled enough to make it worth analysis.

what I will say is that the 4 AI models aren’t particularly interested in less cold uppers as they take the lower heights further south and west to keep most of the country in uppers sub -4c throughout once they’ve dropped again by Wednesday. This probably means little frontal precip as it will miss us but under a cold slack trough features will appear.  That’s what I’d expect from the AI output because that’s what we’d expect to happen based on previous experience. 

beyond the sceuro trough in week 2 …….. looks wedgy to me and if so, getting the jet far enough south will be important.  If the wedge fails to be effective then don’t be surprised to see the gfs 00z idea of a scandi ridge begin to gain some traction. 

[Malarky]

Could the tighter spreads on the ensembles, than perhaps we’re used to, be due to the models not having to contend with an Atlantic system just as the blocking is getting established.

I remember during most other recent chases we’ve had that factor, with fine margins in the storm track leading to vastly different outcomes, even in the short term.

[That ECM]

3 minutes ago, bluearmy said:

hat I will say is that the 4 AI models aren’t particularly interested in less cold uppers as they take the lower heights further south and west to keep most of the country in uppers sub -4c throughout once they’ve dropped again by Wednesday. This probably means little frontal precip as it will miss us but under a cold slack trough features w

That’s my expectation at this time and has been for a couple of days.

 

we will see.

[Lukesluckybunch]

Upgrades on the ICON again

[johnholmes]

Saturday 25 November and a look at the 500 mb outputs from NOAA and ECMWF

Taking ECMWF first for a change and quick summation seems more trough managed than ridging at 500 MB with the -5 C 850 MB covering much of the country for the first 3 days retreating to approx sw Scotland to Kent by day 3(4/12)

NOAA 6-10 and the marked meridional that has developed over the  past 4-5 days is very well pronounced. Contour heights have lowered over the UK, a touch below normal I would say for all, with the trough over Europe also quite a marked feature. Upwind we have a fairly strong mainly westerly flow out of America rounding the main trough, still rather distorted ESE-WNW over ne Canada, back to the much flatter pattern off the west coast. A week agao this was a marked trough/ridge pattern. I suspect this had something to do with how the flow developed in our area of interest.

So a rather cold pattern seems likely for the next 6-10 days with not much change showing on the NOAA 8-14. Detail of actual weather will keep most of you on your toes as the synoptic models try to deal with the finer detail. Also interesting to watch the ECMWF-graphcast interplay over similar short and longer time scales.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

[bluearmy]

15 minutes ago, Lukesluckybunch said:

Upgrades on the ICON again

Looks consistent to me (which is good in the sense that it was one of the coldest 00z ops ) 

[DJ Fart]

1 hour ago, Kentspur said:

That lasted long several "phasing" word replies since can I mention Stockholm?

Jesus, this stopped being funny about a month ago. 

[A.J]

1 hour ago, AdrianHull said:

Words and terms to be banned on here today "850s" "Cold Rain" "Wet Snow" and "Phasing"

Anyways great charts this morning. Ecm continuing with the cold setup all the way to the unreliable. 

Right I'm away to do some Christmas shopping! 

those words cannot be banned, they're an integral part of the world famous NetWeather Winter Bingo game !