Model Output Discussion - Into 2024

[Garthvader]

1 minute ago, MattStoke said:

Coldest mid level airmass over Southern England and Northern France. Don't see that very often.

It wouldn't be a surprise to see weaker heights over Greenland than on most model output currently given that heights are notoriously poorly modelled in that area but that doesn't mean a collapse to any cold spell of course.

Think this was mentioned by one of the pros a day or so ago mountainous regions affect the models closer to t0?

[johnholmes]

Friday 15 Jan update using the upper air charts (500 MB chiefly)

Taking ECMWF first and it has changed today from the last couple of days with both the upper and surface ridge shown as further NW than before. There is also in the last 2 days a signal for colder sir to advect west as the ridge conditions give way to a bit more cyclonic looking. 850 temperatures are brought down below -5 C in the last 2 charts. Is this a trend that will continue? Time will tell

The NOAA charts for 6-10 especially have shifted the C of G of the ridge first east and now again more west. In the more westerly position the European trough is obviously further west thus allowing the possibility of colder upper air moving west. Currently the version yesterday showed the actual contour centre in the NW of the UK with the very high +ve anomaly (+390 DM) being just SW of Iceland. The UK is currently not in any deep cold air on the 6-10 or the 8-14, although this hint at temperatures falling somewhat at 500 MB.

UK Met in the period 9-11 Jan ( their furthest public charts) show both the upper and surface ridge staying just north of northern Scotland. They have the European trough well east with a cut off upper low just south of the UK/nw France edging south over that period.

So with all 3 outputs in the 6-10 day period seem to suggest no deep cold air but with upper and surface ridging being somewhere over or WNW of northern/western Scotland. This suggests a mainly dry spell with frost becoming more widespread but depending on cloud cover for its intensity. The upper pattern to me suggests little probability further out of any break down in the block. Obviously its actual position is going to vary slightly but remaining north rather than south. Models predicting further ahead do seem to suggest that deep cold is possibly 14-20 days away from today? Not my scene so that comment may be incorrect but I’ll leave that to others to firm up on.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

UK Met Office Fax Charts - UKMOMSLP Analysis and Prognosis

WWW.WEATHERCHARTS.ORG

---

UK Met Office . . Europe and North Atlantic MSLP analysis and prognosis charts

 

 

[Beanz]

3 minutes ago, johnholmes said:

Friday 15 Jan update using the upper air charts (500 MB chiefly)

Taking ECMWF first and it has changed today from the last couple of days with both the upper and surface ridge shown as further NW than before. There is also in the last 2 days a signal for colder sir to advect west as the ridge conditions give way to a bit more cyclonic looking. 850 temperatures are brought down below -5 C in the last 2 charts. Is this a trend that will continue? Time will tell

The NOAA charts for 6-10 especially have shifted the C of G of the ridge first east and now again more west. In the more westerly position the European trough is obviously further west thus allowing the possibility of colder upper air moving west. Currently the version yesterday showed the actual contour centre in the NW of the UK with the very high +ve anomaly (+390 DM) being just SW of Iceland. The UK is currently not in any deep cold air on the 6-10 or the 8-14, although this hint at temperatures falling somewhat at 500 MB.

UK Met in the period 9-11 Jan ( their furthest public charts) show both the upper and surface ridge staying just north of northern Scotland. They have the European trough well east with a cut off upper low just south of the UK/nw France edging south over that period.

So with all 3 outputs in the 6-10 day period seem to suggest no deep cold air but with upper and surface ridging being somewhere over or WNW of northern/western Scotland. This suggests a mainly dry spell with frost becoming more widespread but depending on cloud cover for its intensity. The upper pattern to me suggests little probability further out of any break down in the block. Obviously its actual position is going to vary slightly but remaining north rather than south. Models predicting further ahead do seem to suggest that deep cold is possibly 14-20 days away from today? Not my scene so that comment may be incorrect but I’ll leave that to others to firm up on.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

UK Met Office Fax Charts - UKMOMSLP Analysis and Prognosis

WWW.WEATHERCHARTS.ORG

---

UK Met Office . . Europe and North Atlantic MSLP analysis and prognosis charts

 

 

Thank you John, a very measured and sensible piece of commentary nestled amongst the noise this morning

[carinthian]

3 hours ago, carinthian said:

Morning all, another upgrade this morning in the shorter term from UKMO.  Colder flow sourced from that intense cold pool out east making inroads to SE England  during tomorrow. Think further upgrades are possible  out to 96t, especially for the south with chance of light snow from any troughs that form in that flow.

C

First signs of convection across Southern North Sea tomorrow afternoon as the deeper cold air gradually pushes across Eastern Areas of The UK from Denmark , where it is currently very cold. Blizzards yesterday caused a lot of roads in Denmark and Southern Sweden to be closed by drifting snow. ( Pictures from Denmark ). Some models now showing snow showers across Kent and East Sussex for a time on Sunday in association with a transient pool of cold air.

 C

[TEITS]

Going to be honest I am disappointed with the commentary on here these past 24hrs. So much so I couldn't be bothered to post.

Lets begin by saying some of the model output these past 24hrs has been sensational and you could not draw any better charts for the UK. I would even go as far to say the best cold weather output I have seen. So when the bar has been set so high you are bound to see less impressive runs. However even the less impressive runs will deliver what many seek.

The GEFS/ECM mean continue to be fantastic, especially the ECM.

Some people have been referring to a W based NAO. The ECM mean at +240 does the opposite as to me a W based NAO is when the blocking backs W and allows SW,lys via atlantic low pressure systems moving in. The ECM mean is extending the block even further S. The ECM even causes a low pressure in the Atlantic to move W!!

Lets also not forget the argument that all cold spells downgrade is flawed. Even recently some were suggesting the GFS would be right and we wouldn't even have an E,ly next week as low pressure was supposed to track NE into Iceland and our HP sinking over the UK.

Moving onwards and at the moment even the transitional phase from the E,ly to a Greenland block is uncertain with regards to timing and detail and won't be resolved for another 72hrs. I could spend all day typing out various scenarios  beyond this for mid Jan onwards.

Overall a wintry outlook is most likely but could this be a convective N,ly or Bitter convective ENE,ly or will low pressure approach from the SW bringing a blizzard to some locations. Another option is low pressure in the atlantic phasing with the low that is moving S from the arctic, enhancing the bitter flow from the ENE.

[Continental Climate]

Well I was late in checking the forums this morning. Witnessing all the toy throwing and "told you so", comments from certain people was quite a sight to behold. I personally think we are still on for a colder spell of weather. Am I expecting narnia on the 15th? No. I personally think a pressure rise in mid atlantic/ South greenie will.give snow to some but unfortunately not others. I think mentioning downgrades in a model run is fine as that's what that model is currently saying but there is a way of saying these things. What really gets people's back up is "told you so", comments. They truly add nothing to these forums and I personally think they are aimed at the teleconnections guys who do such valuable work here. Personally I hope everyone gets snow but I fear some are going to be disappointed. 

[Dennis]

 

AO and NAO 

[Ice Day]

The oneupmanship and ego on here, which is a WEATHER FORUM is absolutely hilarious.  Thus, it's always been the case and I'm sure it will never change.  Some posters seem to get no pleasure whatsoever from their hobby, so why bother?  

Anyway, sorry mods, off-topic. Definite wobbles from the GFS and GEM this morning, but the UKMO is rock solid and ECM produces an upgrade at day 10, along with an excellent mean, which is worth a rerun.

Will the 6z settle the nerves, or bring about eye-rolling and gnashing of teeth?

Edited January 5 by Norrance
Has caused some offence to others

[January Snowstorm]

The uppers for Tuesday are significantly higher than previous run on 06z gfs. Minus 8s across the South last night are now minus 2 to minus 5

No snow anywhere on that, but it was always marginal to be fair

Edited January 5 by January Snowstorm

[Continental Climate]

10 minutes ago, carinthian said:

First signs of convection across Southern North Sea tomorrow afternoon as the deeper cold air gradually pushes across Eastern Areas of The UK from Denmark , where it is currently very cold. Blizzards yesterday caused a lot of roads in Denmark and Southern Sweden to be closed by drifting snow. ( Pictures from Denmark ). Some models now showing snow showers across Kent and East Sussex for a time on Sunday in association with a transient pool of cold air.

 C

This post and the pictures provided from Denmark are such a stark reminder how difficult it is to get snow into the British Isles. I mean Denmark is what 450 miles away by boat and yet the weather we are experiencing couldn't be more different. So if the global teleconnections are delivering blizzards to Denmark Holland et al but not us can they be said to have failed on a global level? I personally think not. They have currently delivered snow to North West Europe, just not these tiny bunch of islands. We need something ultra special whilst they don't. 

[Lukesluckybunch]

The turn up to greenland at 156 doesn't look sharp enough..a bit flat..could be a problem!

[TSNWK]

06z gfs.  Not such a strong push north the heights into Greenland at day 7. However more of ridge from Pacific attempt towards pole...

No idea how this lands later on... 

Just now, Lukesluckybunch said:

The turn up to greenland at 156 doesn't look sharp enough..a bit flat..could be a problem!

Agreed.  What signal is gfs picking up.  Needs to drop it. 

[Ali1977]

2 minutes ago, TSNWK said:

06z gfs.  Not such a strong push north the heights into Greenland at day 7. However more of ridge from Pacific attempt towards pole...

No idea how this lands later on... 

Agreed.  What signal is gfs picking up.  Needs to drop it. 

I think it’ll end up better and push harder up the west of Greenland , better trigger low 

Edited January 5 by Ali1977

[frosty ground]

no major differences at this point locally, high a little stronger and the low that’s going to push around the high is further west making it look like the high is struggling but it really isn’t 

[Lukesluckybunch]

Just now, Ali1977 said:

I think it’ll end up better and push harder up the west of Greenland 

Surely we need the bulk of it over or to the east of greenland..

[MATTWOLVES 3]

While the gfs has its daily wobbling routine I bring you the ec ens and yes the outlook is promising..These det runs will get itchy feet from time to time and will need to turn to there bigger more experienced brothers and sisters for a little guidance! There's a simplistic way of putting things.

[Dennis]

MJO EC yesterday 

heading from phase3 back to phase2

 

[TSNWK]

Just now, Ali1977 said:

I think it’ll end up better and push harder up the west of Greenland 

Not seeing it..quiet a bit flatter with push into Greenland at day 7.. lows to west of Greenland look postive tilt.. 

Much flatter at day 8 over Greenland..  not good 

[Lukesluckybunch]

1 minute ago, MATTWOLVES 3 said:

While the gfs has its daily wobbling routine I bring you the ec ens and yes the outlook is promising..These det runs will get itchy feet from time to time and will need to turn to there bigger more experienced brothers and sisters for a little guidance! There's a simplistic way of putting things.

They are unbelievably good!

[frosty ground]

Just now, TSNWK said:

Not seeing it..quiet a bit flatter with push into Greenland at day 7.. lows to west of Greenland look postive tilt.. 

Much flatter at day 8 over Greenland..  not good 

much lower heights over Greenland on this run, not sure where the high is going to go.

i think we’ve lost a wheel on this run

[Lukesluckybunch]

1 minute ago, TSNWK said:

Not seeing it..quiet a bit flatter with push into Greenland at day 7.. lows to west of Greenland look postive tilt.. 

Much flatter at day 8 over Greenland..  not good 

Looks to be taking shape towards 192!.

[Captain Shortwave]

At day 7/8 the Azores low becomes temporarily cut off, what we want is for that time to be as short as possible as that low needs to phase with the trough exiting North America. When these phase you get the elongated trough and the subsequent push northwards of the Atlantic ridge. What you don’t want is the low to remain cut off because the jet stream will flatten out the ridge as all the energy rides over the top instead of splitting.

Edited January 5 by Captain Shortwave

[carinthian]

2 minutes ago, Continental Climate said:

This post and the pictures provided from Denmark are such a stark reminder how difficult it is to get snow into the British Isles. I mean Denmark is what 450 miles away by boat and yet the weather we are experiencing couldn't be more different. So if the global teleconnections are delivering blizzards to Denmark Holland et al but not us can they be said to have failed on a global level? I personally think not. They have currently delivered snow to North West Europe, just not these tiny bunch of islands. We need something ultra special whilst they don't. 

Yes, its hard work for you guys but that makes its extra special when you do hit the jackpot .  We need Doggerland to resurface! Yes , small differences  in mileage but big difference in weather. That reminds me of my post Christmas flight from Liverpool John Lennon . Set off in rain and temp of 9c and arrived 1 hour 57 mins later ( record flight time ) in Arlanda Stockholm at -10c in deep snow ! Back to the short term models , at least some cold to tap into for you lot. Could be a lot worse !

C

[Continental Climate]

1 minute ago, MATTWOLVES 3 said:

While the gfs has its daily wobbling routine I bring you the ec ens and yes the outlook is promising..These det runs will get itchy feet from time to time and will need to turn to there bigger more experienced brothers and sisters for a little guidance! There's a simplistic way of putting things.

I personally think perturbation 3 or 16 is sort of where we will end up. A mid Atlantic south greenie blocking around the 15th. What happens after that I'm unsure. It either sinks or it shuffles. 

[IDO]

The good news is that the retrogression signal is solid (due partly to the Pac Ridge), and the 06z hammers that home:

That does mean that a sinking UK high is a nominal risk and that we should, at the worst, get a mid-lat Atlantic high. It looks better from D7 than the 0z.