Model Output Discussion - Snow Watch limited edition

[Paul]

Right then - here we go with a limited 'Snow Watch' edition of the Model Discussion thread. If you want to track the models / radar etc with a view on what the snow chances are wherever you may be in the country, this is the thread. 

We realise this isn't for everyone though, which is why we also have the models, models and more models thread available too - which will be reserved for more general model discussion outside of the realms of 'is it going to snow in x, y or z'.

The models, models and more models thread will also serve as the highlights thread, so posts with enough 'insightful' reactions will be copied over into that one - so please keep using that to help crowdsource the highlights for the wider community to use.

Please also remember, the regional groups are great places and always lively at times like this for much more localised chat around the chances of snow etc. So please use those if you really do just want to focus on your back garden, so to speak. 

https://community.netweather.tv/clubs/

Beyond that, please keep it friendly in here, and report posts you think are a bit iffy, rather than responding to them. 

[Stuie]

Overnight jet profile from the GEFS for Friday morning. You can see why the LP is being modelled further South.

EDIT: Wet bulb levels for Friday morning. You can see where the best chance of snow will be, North Wales, North of the Midlands. Ireland early hours Friday.

Edited March 8, 2023 by Stuie

[MJB]

An area to the SW heading towards work ( Bicester ) and home ( Banbury ) , snow has virtually stopped looking for it to pep up 

[More Runs Needed]

This is essentially the nowcasting thread Can't believe the ensemble spread for 24hrs...

[MJB]

Just now, More Runs Needed said:

This is essentially the nowcasting thread Can't believe the ensemble spread for 24hrs...

I have lost track now of where and when and amounts , it's changed so much

 

[Ali1977]

Just a quick shout out to the MODS, you all do a great job running with these forums, much appreciated

[Garthvader]

2 minutes ago, More Runs Needed said:

This is essentially the nowcasting thread Can't believe the ensemble spread for 24hrs...

Its bonkers trying to keep up with models ,fax etc  gone from possible 5 inches to rain tomorrow imby obviously!

[bluearmy]

Going back a couple days we see todays precip considerably further north of the M4 than modelled.

standard expectation is for things to correct south as the time approaches 

so those assuming that tonight and tomorrow will see southerly corrections are not using todays experience and I would suggest that this is more relevant.  Yesterdays 12z ec looks to have been an anomoly in the level of its trough disruption for tonight and tomorrow. 

[Stuie]

Using the Arpege for Friday lunch, snow chances much better with EA being favoured.

[Snowy L]

3 minutes ago, bluearmy said:

Going back a couple days we see todays precip considerably further north of the M4 than modelled.

standard expectation is for things to correct south as the time approaches 

so those assuming that tonight and tomorrow will see southerly corrections are not using todays experience and I would suggest that this is more relevant.  Yesterdays 12z ec looks to have been an anomoly in the level of its trough disruption for tonight and tomorrow. 

Thing is though there's been a consistent link with the further north today is the further south tomorrow is.

[Mike Poole]

8 minutes ago, bluearmy said:

Going back a couple days we see todays precip considerably further north of the M4 than modelled.

standard expectation is for things to correct south as the time approaches 

so those assuming that tonight and tomorrow will see southerly corrections are not using todays experience and I would suggest that this is more relevant.  Yesterdays 12z ec looks to have been an anomoly in the level of its trough disruption for tonight and tomorrow. 

It has been obvious for some time that the fortunes of today’s system and tomorrow’s are linked - the trend over the last couple of days for today’s system to be modelled further north, balanced by a trend to bring tomorrow’s system south.  

Now that today’s system has ‘happened’, I’m not sure whether southwards corrections to tomorrow’s system will continue, but equally there is no reason I can see for it to suddenly trend north.

Edit, see @Snowy L beat me to it.

Edited March 8, 2023 by Mike Poole

[Garthvader]

2 minutes ago, Mike Poole said:

It has been obvious for some time that the fortunes of today’s system and tomorrow’s are linked - the trend over the last couple of days for today’s system to be modelled further north, balanced by a trend to bring tomorrow’s system south.  

Now that today’s system has ‘happened’, I’m not sure whether southwards corrections to tomorrow’s system will continue, but equally there is no reason I can see for it to suddenly trend north.

Thanks as ever i suppose...more runs needed?

[bluearmy]

2 minutes ago, Mike Poole said:

It has been obvious for some time that the fortunes of today’s system and tomorrow’s are linked - the trend over the last couple of days for today’s system to be modelled further north, balanced by a trend to bring tomorrow’s system south.  

Now that today’s system has ‘happened’, I’m not sure whether southwards corrections to tomorrow’s system will continue, but equally there is no reason I can see for it to suddenly trend north.

Edit, see @Snowy L beat me to it.

Looking back over the past 4 runs of gfs/ec/gem, the 0c isotherm has ranged between Manchester and London at most. But take out the two widest spreads and you’re left very much with a line approx Birmingham to norwich

allow thirty miles north/south on that and I see no reason for that to change 

[feb1991blizzard]

7 minutes ago, bluearmy said:

Looking back over the past 4 runs of gfs/ec/gem, the 0c isotherm has ranged between Manchester and London at most. But take out the two widest spreads and you’re left very much with a line approx Birmingham to norwich

allow thirty miles north/south on that and I see no reason for that to change 

look at the spread on the ens though.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from GFS, 00Z

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from ECMWF, 00Z

 

[Battleground Snow]

A very slight shift south on the gfs 06z, for Thursday, not much in it though 

[bluearmy]

11 minutes ago, feb1991blizzard said:

look at the spread on the ens though.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from GFS, 00Z

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from ECMWF, 00Z

 

Ens to T 48 hours have never been of interest to me …… there is an argument that the resolution difference at such short range should make less difference so maybe I’m bang wrong on that ! 

[Stuie]

1 hour ago, Stuie said:

Overnight jet profile from the GEFS for Friday morning. You can see why the LP is being modelled further South.

EDIT: Wet bulb levels for Friday morning. You can see where the best chance of snow will be, North Wales, North of the Midlands. Ireland early hours Friday.

6z GFS does show the above. 

[MJB]

Friday looks like widespread snow

[TEITS]

Well after numerous model runs im still non the wiser what to expect. Im expecting to see snow falling but the real question mark is how much, if any lying snow. The models consistently suggest less accumulating snow for E Anglia compared to Midlands/Wales. This most likely is due to the influence of the N Sea. What complicates matters is my location has often been the boundary between the mild/cold.

Looking very good for W Midlands/N Wales/N Midlands/S Yorks. Also worth mentioning is the strong winds as the low tomorrow tracks E tomorrow night/friday.

[EML Network]

This is one to watch, Thats a few hours of white out conditions for Lincolnshire and  East Anglia.

Edited March 8, 2023 by EML Network

[MJB]

Wouldn't it be great for the LP  out West to slide on through

[Updated_Weather]

Just now, EML Network said:

This is one to watch, Thats a few hours of white out conditions for East Anglia.

Can you show the precipitation chart for this? Wanna see how I'd fare

[Ali1977]

2 minutes ago, Updated_Weather said:

Can you show the precipitation chart for this? Wanna see how I'd fare

 

[bluearmy]

4 minutes ago, Battleground Snow said:

A very slight shift south on the gfs 06z, for Thursday, not much in it though 

I think the 0c goes a bit further north during the day so just the usual to and fro, run to run - of course to those in the Birmingham to Manchester area that will matter a lot ! 

[Updated_Weather]

1 minute ago, Ali1977 said:

 

Bit light, need that slightly further east - But I am sure it's heading south so maybe more back end for me!