Model output discussion - into the last third of January

[carinthian]

Latest fax has the fronts making very slow or no progress across the British Isles on Wednesday. There is a uncertainty now of how much a push of the mild air will make .

 

 

 

. Possible snow along this boundary for some.

 C

Edited January 24, 2021 by carinthian

[IDO]

Def a cluster of gefs similar with the phasing of the ecm allowing a brief ridge and although the ecm is the cleanest example, cannot rule something similar:

This clearly is where FI starts as we know getting a wedge into that corridor to our north will change the flow of the cold. This is the more desirable option and hopefully UKMO and the gfs op will trend in that direction today. Phasing as far out at d6 is a difficult call as we could see spoiler lows cut off those transient heights. 

The gfs op does not get interesting until late in FI, when that signal for heights to the NE pops up again. There remains no obvious signal from the gefs at that range or trend. The biggest forcing cluster is the Atlantic ridge and a small cluster supports something similar to the op but again not as clean.

Looking at London, very little cold, just slightly below average in the next 2-weeks:

Some of the members that were similar to the ecm op at d7 keep it cold throughout and this highlights that divergence in potential going forward. The ecmo op -v- mean:

So similar to the gefs, def a split.

Edited January 24, 2021 by IDO

[nick sussex]

The ECM was looking good until the phasing calamity with that shortwave energy moving west out of Norway. Without that more trough disruption and energy heading se .

The models do look all at sea though and really not a time to put too much faith in their later outputs .

As for the UKMO that’s even more volatile and the changes between its runs is scarcely believable . 

[Nick F]

Definitely a signal for +ve heights to N/NE in the extended EPS mean, but also deep -ve height anomaly just to the west of UK, could be close but not cigar to getting an Ely/NEly initially, until the resurgence of the Atlantic jet stream calms down and shifts south to allow +ve heights to the NE to build further SW to allow us to tap into cold from the E or NE as enter early February. But equally, the models maybe overdoing upper flow energy over the Atlantic. More runs needed ...

Edited January 24, 2021 by Nick F

[Gowon]

The Arpege has quite a few sliders - Tuesday into Wednesday and Wednesday into Thursday, but the other models don't agree.

 

 

 

 

[Tim Bland]

Whilst I await this weekends snow..Here’s a look at next weekend...

[Chesil View]

28 minutes ago, Nick F said:

Definitely a signal for +ve heights to N/NE in the extended EPS mean, but also deep -ve height anomaly just to the west of UK, could be close but not cigar to getting an Ely/NEly initially, until the resurgence of the Atlantic jet stream calms down and shifts south to allow +ve heights to the NE to build further SW to allow us to tap into cold from the E or NE as enter early February. But equally, the models maybe overdoing upper flow energy over the Atlantic. More runs needed ...

Yes Nick. The operational runs seem all over the place one moments it's wedges heading towards beasts next run its Atlantic all the way. Real lack of consistency. I place FI at about 120 hrs at the moment.

[snowysouth]

1 minute ago, Tim Bland said:

Whilst I await this weekends snow..Here’s a look at next weekend...

Rain again for Dorset then I'd rather have a cold sunny day than cold rain

[Tim Bland]

28 minutes ago, D.V.R said:

The Arpege has quite a few sliders - Tuesday into Wednesday and Wednesday into Thursday, but the other models don't agree.

 

 

 

 

Insane run!! Only a few days away as well! It wouldn’t take much of shift in the pattern  for this to happen ,fronts just need tot are a slightly different track and slide instead of across.   and you would expect a high res model to pick up a short term change first. ...

[Tim Bland]

Looks ECM nailed it - radar for 8am and ECM from yesterday for 9am 

[Man With Beard]

Ecm clusters D8-D10 pretty good agreement now on a trough into central Europe which should advect colder air back through the UK. Troughs lining up to approach the UK afterwards - what transpires will probably depend on how much cold air is in front of them. More snow/rain lines to be drawn (hopefully not 5 miles north of my house this time!)

[northwestsnow]

6 minutes ago, Man Without Beard said:

Ecm clusters D8-D10 pretty good agreement now on a trough into central Europe which should advect colder air back through the UK. Troughs lining up to approach the UK afterwards - what transpires will probably depend on how much cold air is in front of them. More snow/rain lines to be drawn (hopefully not 5 miles north of my house this time!)

Crikey! Lots of options...

Sorry you just missed out today MWB..

Hopefully more opportunities before Feb is done!

[northwestsnow]

So, things look incredibly complicated over the coming weeks...

Atlantic coming alive but the jet being forced SE by wedges of heights to the NE,assisted by troughing dropping into Europe.

Countering that annoying cells of HP across Iberia.

In short, fortunes are going to ebb and flow across the UK.

[sebastiaan1973]

30 minutes ago, Man Without Beard said:

Ecm clusters D8-D10 pretty good agreement now on a trough into central Europe which should advect colder air back through the UK. Troughs lining up to approach the UK afterwards - what transpires will probably depend on how much cold air is in front of them. More snow/rain lines to be drawn (hopefully not 5 miles north of my house this time!)

 

We see a lack of high pressure at Scandinavia. So the EC-oper seems to be quite lonely.

[BLAST FROM THE PAST]

Moderate snow in Redhill, sticking immediately.  Models showing further chances over next 10 days too.  Decent tweaks neartime for cold to not go away for long....if indeed at all for some parts 

 

BFTP

[Vikos]

 

 

 

 

[Anthony Burden]

1 hour ago, Nick F said:

Definitely a signal for +ve heights to N/NE in the extended EPS mean, but also deep -ve height anomaly just to the west of UK, could be close but not cigar to getting an Ely/NEly initially, until the resurgence of the Atlantic jet stream calms down and shifts south to allow +ve heights to the NE to build further SW to allow us to tap into cold from the E or NE as enter early February. But equally, the models maybe overdoing upper flow energy over the Atlantic. More runs needed ...

Good morning Nick,charts struggling this morning to find the right way forward but looking more 

east to west scenario in the longer term.Short term some suspicion on Atlantic push,ie will it stall,

great weather watching in the meantime looking out of window in Oxford still snowing around in imperial 

measurements 3 inches of lying snow picturesque scenes.

 

[MATTWOLVES 3]

I'm glad many of you have had a snow fix,for me its the 6th time since December of falling and settling snow...thats pretty good tbh.. just noticed those 0z ens are showing lots of wintry fixes moving forward..

Also where skies clear tonight and you have lying snow,some really low minimums are looking likely...even -10 possible..At last...proper cold folks.

Enjoy the Snow,but don't get breaking anything...excitement and falls go hand in hand..

[TEITS]

Fasinating watching the output over the past few days. Whilst next weekend is interesting I am more interested in beyond (around 3th/4th Feb) when we could see a cross polar flow with an incredibly cold airmass on the S flank of the high pressure extending from the arctic.

Already seen more snow than the past few winters but that wasn't difficult to achieve!

[Battleground Snow]

Interesting para wedge development at 132

 

[phil nw.]

Morning all, 

Great to see many more of us further south have seen snow but please keep these reports to the regionals or general discussion threads please. 

Let's keep this one to model discussion otherwise it soon gets off track with off topic responses. 

Thanks all. 

[Ice Day]

4 minutes ago, Battleground Snow said:

Interesting para wedge development at 132

 

Even more interesting at 162, not a million miles from ECM 168 this morning

  

[Notty]

GFS(P) says Snowmaggeddon for the South next Saturday before the cold tucks in behind it.

[Battleground Snow]

Big snow event at 150, would be borderline blizzard conditions

[BLAST FROM THE PAST]

3 minutes ago, Ice Day said:

Even more interesting at 162, not a million miles from ECM 168 this morning

  

That low between Iceland and Greenland is a spoiler, It will off the main thrust which will be above that

 

BFTP