Model output discussion - Winter has arrived and the hunt for cold is on

[Mike Poole]

Dark times, but how dark?

Let's start with the latest, ICON 18z T120:

That jet has everything, the arrow head, the forked tail, the creature sniffing it's behind, and an in-your-face face in the middle too!! (looks like a former minister, can you guess which one?) But it is what is expected, and it is south of the UK.  That is the position that now needs to to be the baseline from which longer term UK predictions are made...if it's going to be zonal it will be cold zonal, and if any mechanisms can produce some amplification on that then the coldies amongst us in more northern parts of the UK can quickly be in the game.

FFwd to T240, here GFS, GEM and ECM from the 12z runs:

Yes, it's horrible weather for us to come, I know that, but beyond that no model has got anything sussed, look at the purples, he vortex doesn't have to be Greenland, it could end up, well not anywhere! but it could be quite a few places, we will see...

Edit. I've tried 4 times to get this post right but am being fought by the system and my own incompetency, it is more or less right now.

Edited December 7, 2019 by Mike Poole

[Mike Poole]

This just looks horrible, doesn't it?  On any level, whatever the result of the election, this is what we will probably face the next day:

GFS 18z T126.

A new dawn, maybe.  Hardly....but we await the election result as the weather, both are massively uncertain at this stage... we will see...

[Rocheydub]

Not sure why there is so many despondent posts, I've seen worse charts at 180 (GFS 18z) There is a loosening of a grip on Greenland by the PV, and a rising in SLP. There is plenty of potential in this chart, a few minor corrections and we could be sitting pretty from a oldies perspective.Maybe even a link up between the Pacific HP and an Atlantic one. 

Edited December 7, 2019 by Rocheydub

[Snowman.]

That Arctic high is really doing some work, may not be affecting us but it's definetly keeping the TPV disorganized.

 

[Rocheydub]

I think the pub run is a great run rolling out now. The Arctic is in smithereens and pressure is rising all over the place up there!

[snowray]

10 minutes ago, Snowman. said:

That Arctic high is really doing some work, may not be affecting us but it's definetly keeping the TPV disorganized.

 

In fact we have 2 or 3 wedges of Artic highs forming now and HP trying to push up into Greenland, interesting to see how this will develop, be nice to see a clump of the PV drop south over us.

[swfc]

quite a change on the nhp.areas of blocking seem to be popping up be it only minor.pv is under pressure here on the 18z be it fi.interesting

[Mapantz]

2 hours ago, Dennis said:

the euro4 model sees possible snow showers sunday later on the day

I think that first chart is rather optimistic for areas further South.

Here's the UKV model for the same time:

[Don]

4 minutes ago, Mapantz said:

I think that first chart is rather optimistic for areas further South.

 

Lol, that almost puts me in the firing line!  Yes, rather optimistic indeed!

[feb1991blizzard]

2 minutes ago, Mapantz said:

I think that first chart is rather optimistic for areas further South.

 

I think it is optimistic full stop, BBC graphics have snow only for the Scottish highlands tomorrow and most places even in Northern England have max temps of 8c and min's of 5c, that smacks to me of height of 0c isotherms of about 700-800m

[northwestsnow]

1 minute ago, feb1991blizzard said:

I think it is optimistic full stop, BBC graphics have snow only for the Scottish highlands tomorrow and most places even in Northern England have max temps of 8c and min's of 5c, that smacks to me of height of 0c isotherms of about 700-800m

Feb, we struggle to get snow in a PM flow with 850s at -8 @200m asl...

 

[feb1991blizzard]

Just now, northwestsnow said:

Feb, we struggle to get snow in a PM flow with 850s at -8 @200m asl...

 

Yes - we certainly don't get snow in December with daytime max's of 8c - you usually need 2c or below, absolute tops 3-4c

[snowray]

4 minutes ago, feb1991blizzard said:

Yes - we certainly don't get snow in December with daytime max's of 8c - you usually need 2c or below, absolute tops 3-4c

I think that there might be a few flakes though in any heavy showers in the evening above about 200m? Could be wrong though.

[feb1991blizzard]

3 minutes ago, snowray said:

I think that there might be a few flakes though in any heavy showers in the evening above about 200m? Could be wrong though.

Its possible somewhere i suppose.

[snowray]

Very strange looking chart but once again we see a glimmer of hope in deepest FI, cold air moving in there just in time for Christmas week.

I think GP mentioned that we might see something more interesting by late December.

[snowray]

13 minutes ago, feb1991blizzard said:

Its possible somewhere i suppose.

Very marginal though, uppers -3c, dew point around -1c. 

Edited December 7, 2019 by snowray

[Don]

24 minutes ago, snowray said:

Very strange looking chart but once again we see a glimmer of hope in deepest FI, cold air moving in there just in time for Christmas week.

I think GP mentioned that we might see something more interesting by late December.

According to his winter blog, GP sees February as being the best opportunity for colder weather in north west Europe, with December and January largely cyclonic with average to above average temperatures.  However, that's not to say we won't see something interesting develop in late December of course.  Worth bearing in mind that December 2000 had a very cold final week which masked an otherwise mild month.  The CET for that month was 5.8C.  Imagine how mild that month would have been otherwise!

Edited December 7, 2019 by Don

[snowray]

15 minutes ago, Don said:

According to his winter blog, GP sees February as being the best opportunity for colder weather in north west Europe, with December and January largely cyclonic with average to above average temperatures.  However, that's not to say we won't see something interesting develop in late December of course.  Worth bearing in mind that December 2000 had a very cold final week which masked an otherwise mild month.  The CET for that month was 5.8C.  Imagine how mild that month would have been otherwise!

Yes he said February could be our main event for winter this year but I'm sure that late December was also mentioned as having a chance for some cold also. It would just be nice to get some cold in for once over Christmas, even a frost but obviously anything white would be lovely.

Anyway the Ensembles for central England are painting a rather chilly picture with snow chances throughout, so there is some interest, better than last December for sure.

Edited December 7, 2019 by snowray

[Frosty.]

Looking at the GEFS 0z mean longer term there is a suggestion of heights encroaching from the south with a tendency towards more of a N / S split with the south becoming less unsettled towards christmas but for most of the run its a very unsettled outlook and cold enough at times, especially around mid month for snow to fall potentially across most of the uk but the main risk of snow is across northern hills / mountains.

[West is Best]

A wild week ahead. For cold lovers it's not a bad one though. We remain for the majority of the week north side of the PFJ. Hill snow will feature e.g. on Wednesday. Lots of heavy rain and gales too. 

I'm intrigued about Thursday. GFS has a pretty flat zonal flow with heavy rain. UKMO continues to see a buckled jet with a northerly. ECM is literally halfway between the two.

[Dennis]

todays euro4 forecast 

[legritter]

Good morning gang. Certainly a very turbulent week or so looking at this mornings charts , no BOOM charts to get me excited but as ever with a bit of tweaking on the ECM IN Its later stages we could get there with some colder 850s dragged further south .So over to the GFS For some eye candy ,its all frustrating but we do have some  ery interesting synoptics around and this can throw up surprises for the UK , take care gang STellas all round .

[MattStoke]

8 hours ago, northwestsnow said:

Feb, we struggle to get snow in a PM flow with 850s at -8 @200m asl...

 

I saw heavy snow at 146 m with -2’C 850s last winter.

[Ali1977]

Jet seems to be further south and into Spain on the ECM mean at 240, so there may be a few colder EC ENS members amongst them!! 

[Jordan S]

Arpege has dramatically switched to output that matches more the Ecm and Gem for tonights stormy conditions to be largely restricted to southwestern regions where gusts of 60-70mph are possible with 70-80mph along the Irish Sea and the English Channel elsewhere inland for central and Eastern areas 30-40mph a big step back from the 55-65mph it was showing yesterday evening and indeed much of yesterday.

Very windy for the north and east of Scotland too tonight. 

There is uncertainty and a subtle shift east could mean the scenario played out by the Arome the Arome sticking to its output with a more widespread general swathe of very strong winds across much of England and Wales with gusts of 50-60mph widely. Although Arome can at times overdo windspeeds it's still worth keeping an eye on. 

Arome. 

I expect the Arome will tone the expected wind gusts for many parts of central and Eastern England down towards other models with restricting the worst conditions for the southwest but a stormy latter half of the night for inland areas of England with gusts exceeding 50+mph not to be ruled out atm. 

Anyway a more detailed look..

Showers packing into much of Northern and western areas throughout today windy too with heavy downpours in a few places there will also be some sunshine too. These showers will fall as sleet and snow for parts of Scotland mostly on high ground with a wintry mix to lower levels perhaps high ground for the Northwest of England too.. 

Into the early part of tonight some showers die away but winds begin to strengthen rapidly for the West and southwest of England along the Irish Sea, Northern Ireland and much of England with gusts likely of 50-60mph for the far southwest with perhaps around 60-70mph for exposed coasts 30-40mph across England and Wales this will be blowing from a northwesterly direction with troughs running along the flow into many parts of England and Wales bringing heavy areas of rain southeastwards.

winds perhaps ease for a time for many places inland for parts of england excluding the southwest of England southwales winds continue increasing with gusts here of 60-70mph perhaps as high as 80mph through the Irish Sea. Later in the night its likely to turn very windy once again for many inland areas of England with very strong gusts of wind from the northwest then north perhaps 40-50mph widely but there is uncertainty and a low risk of 50-60mph still remains very strong winds for Eastern coastal areas come mid morning tomorrow. 

Tuesdays sees another very active period with a warm front pushing into Western areas giving Western Scotland a lot of rainfall to start the day here, a dry start for the east but winds rapidly pick up with gales in places the warm front fizzles out with a very active Ana cold front moving through all areas this will contain some torrential downpours with a likely squall line developing towards the back edge wind gusts of 50-60mph for many for a short period in that area. Once this sweeps through colder air moves through all with showers of snow for Scotland turning wintry for other northern areas. 

Rather interesting scenerio being played out by the GFS for next Saturday with two areas of heavy rain moving in for next Saturday morning then later Saturday bringing heavy rain for southern England but some heavy snow for northern England and parts of the Midlands.. don't take the bottom charts as gospel but demonstrates the overall cooling trend through next week. 

If we take a look at the blended average output of the Gfs, Gem and at times Ecm for the next 10 days..

Stormy for many southwestern areas tonight then perhaps more widely later in the night elsewhere A very unsettled week ahead with frequent rain and strong winds with likely stormy periods at times with some colder air flowing into these areas of low pressure then snow is not to be ruled out for lower levels in the north at times with even a little wintriness for areas further south perhaps.

Edited December 8, 2019 by jordan smith