Cold hunt - models and chat

[TEITS]

7 minutes ago, Daniel Smith said:

so perhaps a continuation of lows sliding SEwards bringing an occasional snow risk, brief less cold blip this weekend.

That is exactly the part I am currently watching closely.

I may very well be wrong but im spotting the signal of an end to the sliding lows as upstream it becomes much more amplified than currently progged. That is especially true of the flat as a pancake ECM. My instincts are telling me we could see high pressure to become centred from Scandinavia to Iceland. All of which occurring within the relatively reliable timeframe of +168!

Could the beast be finally let out of its cage?????

Edited January 28, 2019 by TEITS

[booferking]

6 minutes ago, Polar Maritime said:

Please no more Meto warnings in here. Just Model discussion.

If anyone wants to open a thread up for snow chances this week to follow the event then that's no problem, Also Meto posts would be allowed in there. 

Regards.

Might need to open another Midlands and Southeastern thread they cant seem to find it mods..

Edited January 28, 2019 by booferking

[BlueHedgehog074]

Everyone’s covered it well, so just a little summary of the models for the next few days.

Tomorrow: something white could fall from the sky.

Wednesday: something white could fall from the sky.

Thursday: alien invasion from the South-West. 

Friday: alien invasion continues for parts of the U.K threatening the island with lots of white powder! 

Saturdays: the aliens may continue the invasion, then go back home for tea on Saturday night. 

[weirpig]

Euro 4 6z    for tuesday

[SMU]

20 minutes ago, TEITS said:

Have to say at the moment the locations favoured are N Midlands/ W Midlands/Wales. The least favoured dare I say is E Anglia/SE.

This is simply due to several factors. The low on Tues was always likely to go SE of the UK and this has proved to be the case. We are dependant on snowfall via the front moving SE. This is likely to fizzle out as it heads SE.

End of the week/Weekend. Most could see snow, however the locations I mention could see it remain as snow. This is due to the flow becoming ENE,ly and the warming effects of the N Sea will reduce the risk of snow for many E areas and this includes N England (except hills).

 

The medium range continues to intrigue me and the outlook isn't going to be as flat and mild as the ECM suggests in my opinion. Big changes likely to occur in the medium range over the next 48hrs. Watch this space!!!

Hi TEITS not strictly correct there for Thursday 

E/SE will be *more* favoured than North midlands due to the energy moving East along the front - its not a ' normal ' scenario

Once you get energy travelling east you get More energy along the whole front plus the warm air advection gets pushed east as well-

The GFS with its circular Northward bias pushes everything north where as the high Res ICON moves it East-

If we refer to history- Just like the channel lows - ( & indeed the fax chart ) The North snowline from the GFs looks WAY north out of kilter ....

Edited January 28, 2019 by Steve Murr

[kold weather]

06z GFSP is a little south with the southern boundary of the snowfall again, due to a more elongated LP than the 06z OP.

 

[shaky]

5 minutes ago, kold weather said:

06z GFSP is a little south with the southern boundary of the snowfall again, due to a more elongated LP than the 06z OP.

 

 

8 minutes ago, weirpig said:

Euro 4 6z    for tuesday

Thats shows 5 to 10cms for leicester but i dont believe it at all!!

[Tim Bland]

Longer term signals starting to look more positive again @bluearmy do you work in meteorology? If not you should do as this is exactly what you were saying would start showing yesterday 

[Updated_Weather]

Just now, shaky said:

 

Thats shows 5 to 10cms for leicester but i dont believe it at all!!

Best to expect little and then act surprised if you get more!

[Northwest NI]

38 minutes ago, ghoneym said:

Here is my take on Tuesdays snow events using that trusty old Swiss HD model. 

By Tuesday morning the centre of the low pressure system is out in the bay of Biscay, West of Nantes.  Precipitation from the front reaching the Welsh Eastern coast is just starting to show.  The charts can be moved on in 1 hour time slots but I have done it in 2 hour time slots here to save posting too many charts

The Welsh Eastern coast

Edited January 28, 2019 by Northwest NI

[offerman]

1 minute ago, shaky said:

 

Thats shows 5 to 10cms for leicester but i dont believe it at all!!

Looking at that,  no lying snow in all southwest,  apart from the moors .

[kold weather]

ECM op has decent support from the ECM ensembles. There is a significant minority that are further south (I'd say 30-40%) however, then maybe 10% are further north.

Most still do give a decent snowfall up towards at least N.Midlands, but a definite increase in the models hitting the south as well. Main zone looks like S.Midlands upto that Liverpool-Hull line I mentioned earlier, but still significant range.

 

[Tim Bland]

Just now, Updated_Weather said:

Best to expect little and then act surprised if you get more!

Although we all know that most on here are anticipating snowmagedon on Weds morning and instead will be crying into our coco pops whilst the last bit of slush is thawing outside I think Thursday is the main event this week !

[Updated_Weather]

Just now, Tim Bland said:

Although we all know that most on here are anticipating snowmagedon on Weds morning and instead will be crying into our coco pops whilst the last bit of slush is thawing outside I think Thursday is the main event this week !

As long as I get snow, I won't put anyone in the naughty corner for telling me different!

All jokes aside, very interesting week coming up! Tuesday could be a taster before main event on Thursday like you say, although I wouldn't be too surprised if some surprises happened on Tuesday.

[feb1991blizzard]

9 minutes ago, kold weather said:

06z GFSP is a little south with the southern boundary of the snowfall again, due to a more elongated LP than the 06z OP.

 

Looks to me like the whole thing is further North, FWIW i don't think it will verify though.

[Deep Snow please]

19 minutes ago, Polar Maritime said:

Please no more Meto warnings in here. Just Model discussion.

If anyone wants to open a thread up for snow chances this week to follow/discuss the event then that's no problem, Also Meto posts would be allowed in there. 

Regards.

Hopefully take some of the workload off you...

 

 

[MattStoke]

13 minutes ago, Steve Murr said:

Hi TEITS not strictly correct there for Thursday 

E/SE will be *more* favoured than North midlands due to the energy moving East along the front - its not a ' normal ' scenario

Once you get energy travelling east you get More energy along the whole front plus the warm air advection gets pushed east as well-

The GFS with its circular Northward bias pushes everything north where as the high Res ICON moves it East-

If we refer to history- Just like the channel lows - ( & indeed the fax chart ) The North snowline from the GFs looks WAY north out of kilter ....

ICON has the largest totals towards the west, not the east.

[P-M]

Is it true that the deeper the LP the more northerly track it takes? Not sure this even applies in this instance but I thought I'd read that somewhere.

[Polar Maritime]

GFS keeps us on the cold side, With Easterly attempts into the run and -11 uppers touching the S/E.. All for fun at this range but signals are there.

[Methuselah]

4 minutes ago, Northwest NI said:

The Welsh Eastern coast

Saw that NWNI. Thought it might refer to New South Wales. Which probably doesn't have an east coast, either?

[kold weather]

4 minutes ago, feb1991blizzard said:

Looks to me like the whole thing is further North, FWIW i don't think it will verify though.

Yes it does as the whole thing orientates N-S in the end so the front would go way north with that set-up.

HOWEVER, that is mega unlikely right now and it has only 3-4 ensemble members out of all the ECM and GFS ensembles (that's 70 different members!)

Also worth noting the GFS has the southern boundary very far south. Its a great run for most parts of the country I have to say.

Edited January 28, 2019 by kold weather

[bluearmy]

The reason for the eps ens mean looking flat out west is the binary clusters of ridging/troughing - the week 2 outlook depends on whether you expect things to amplify or stay flat ............caution that the ec46 week 3 later could suffer from this smoothing out on the mean/anoms and look a bit meh ......

[bluearmy]

1 minute ago, alexisj9 said:

Where will the heavy snow in the se warning come from, in that case, as there'll be none on that front, the way it's currently modelled. I wish I could see what the warning is based on, cause they wouldn't bother with a snow warning, for that front down here. Unless it is stronger. Ice warning on it's own perhaps.

The warning is for 1 to 3 cms .... that’s not heavy .......

[kold weather]

Interesting GFS ensembles as well this morning for Thursday.

So the basic pattern is more or less locked down, still a few outliers but the general idea is there. For the Midlands/Wales this looks an absolute lock to me. For places north and south of there things get much more uncertain.

Basically there is disagreement about exactly the distribution of secondary lows and the shape of the main low. These small changes are making a big difference over our islands as to where the snowfall ends up being. ECM ensembles are likewise showing similar uncertainties. (for example, my location has anything from 0cms to 20cms on the ECM ensembles).

I'd not like to try and forecast the northern and southern boundaries for the snowfall as it really depends on the shape of the low and how far north it ends up forcing the front.

The more W-E is better for the south, the more N-S angle is better for the north and Scotland.

 

Edited January 28, 2019 by kold weather

[feb1991blizzard]

1 minute ago, bluearmy said:

The warning is for 1 to 3 cms .... that’s not heavy .......

Heavy is the PPN rate - you can have 10 mins of very heavy snow causing 3cms - sorry to be a pedant!  

Thanks for the EPS update meanwhile, could be one of those situations where after the 12z eps, we could bin the 46 dayer as the 12z eps suite might change, however, if the 46 dayer still finds a way to mean blocking given what you say, that would actually increase my confidence to back over 50% wrt proper deep cold.