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

[tight isobar]

8 minutes ago, Stuie W said:

Well, tbh,I quite like where the bulk of the vortex is, Canada it isn`t. Yep some straw clutching but there is interest there.

Indeed there is interest, and ensembles are certainly cranking the odds....for me the Xmas period still holds interest... but the turn of the year is more than probably the breaking point as highlighted via snaps... with polar points with decent exactions... but as some suggest trough alignment will look to be the headache... but surely we’ll get lucky as profiles note,,,also the 850 hpas....gaining bunched clustering of desired viewing... 

Edited December 16, 2019 by tight isobar

[damianslaw]

Reliable timeframe - about 120hrs, all models in agreement of the longwave trough dominating becoming stuck over the UK thanks to strong heights both to the east and to a lesser extent over Greenland, end result bands of rain circling in on themselves, and staying fairly mild, as we begin to pick a SW feed - but not overly mild as the source is mid-atlantic.

As we approach christmas, models are showing various scenarios, which indicates uncertainty - GFS wants to move the trough slightly east with heights building in and pushing east, then goes haywire, with a rapid low development around Boxing Day (very odd and probability looks very slim), UKMO showing the trough also moving east, but doesn't look like building a ridge, which could then mean we see a colder feed from the NW, ECM, wants to build a strong ridge to our east pulling in a mild southerly just in time for christmas, but interestingly then shows heights building to the NE which could usher in a much colder continental feed before New Year.

 

[Jordan S]

Gfs, Ecm and Gem all agree on very wet conditions for most of the country but they seem to bring the wettest conditions for central and southern UK.. 

GFS.. 

This evening shows a theme of weather fronts getting rather stuck as they push into southeastern England with waves developing on them in the coming week or so.. 

Tomorrow morning..

Friday..

Tuesday (Christmas eve)

Wednesday (Christmas day)

Wednesday Very wet and windy with gales in places with a conveyor belt of heavy rain extending all the way down to northern Spain and Portugal which will bring a lot of rain for Western areas of England, Wales and Scotland and especially Ireland during Wednesday with strong mild southerly winds with a small area of low pressure developing in the flow with Very strong gusts where that tracks certainly a nasty feature this all then transfers east effecting all areas by the end of Wednesday. 

Gem for Wednesday..

The Gem then goes exceptionally wet for England and Wales in particular with numerous slow moving weather systems bringing alot of rainfall with very strong winds at times in some of these low pressure systems.. Likely overdone but something to keep an eye on with the ground so saturated already. 

Heavy rain reintensifying to the south for Thursday..

Another low quite a vigorous one bringing very strong winds and more heavy rain into southern UK Thursday night..

Saturday morning more coming into the south..

By Saturday evening more heavy rain pushing into southern counties moving north..

A drier day or so before more heavy rain pushes into the west and southwest effecting most during tuesday christmas eve..

Then this low gets stuck across the UK upto day 10 with areas of heavy rain stagnating around the country keeping the very wet weather going.. 

Ofcourse this very wet update not to be taken too literally especially with any individual systems towards 7-10 days but its definitely a worrying update from the Gem from a flooding perspective and if that proved correct then many more problems with flooding would occur. 

The Ecm not as wet as the Gem that's no suprise but still wet frequently with strong winds at times here's the rainfall accumulation from the ECM.. 

Gem.. 

Accumulated rainfall for Scotland similar tbh. 

It's just a snapshot of what the models are showing and more influence from higher pressure as was shown a couple of days ago still a possibility but isn't looking that likely atm up until Christmas anyway. 

Edited December 16, 2019 by jordan smith

[Rayth]

Ecm having a taste of the GFS outlier moonshine at the end 

 

Edited December 16, 2019 by Raythan
Error

[SMU]

UKMO 168 has the ridge favourably aligned V the ECM

[January Snowstorm]

Models all over the place for Christmas.

18z different again with -nao becoming more and more evident. Heights now entirely gone over Europe. A white Christmas still has a chance...need more upgrades though!! At least it's looking colder and more interesting 

[ICE COLD]

At least it will feel seasonal on the big day . That’s according to the GFS 18z tho

[BLAST FROM THE PAST]

2 hours ago, I remember Atlantic 252 said:

shame all changed 22 years on, I mean a January E'ly, what's that? under 21's won't know what a winter is living here

Really?  Maybe the folk thought the same in the 70s.  Anyway, stuff to play out, I like the model volatility approaching Christmas.....calm it won’t be....very interesting and imo no doubt very seasonal XMas for some/many...

 

BFTP

[damianslaw]

I don't usually remark on GFS 18z post 120 hr mark, as it has a tendency to 'go off on one' the further from the reliable you get, but interesting to note it seems to be aligning more to the UKMO output 120hr-144 hr period, with a slight more easterly push of the trough, and less in the way of ridge development to our south, hence it shows a deconstructing trough sat in situ over the UK by christmas eve, with a channel runner of sorts, and energy well seeming to spin in on itself, and heights developing more to the NW, which might evolve into a set up that sees the trough simply sinking away southwards becoming much less of a force last week of December and we then look to see where ridge development forcing comes from - the NW, NE, SE??

 

[Mucka]

"The ridge part 2" ?

 

 

Certainly an element of de ja veux about the way the post Xmas period is shaping up.

[damianslaw]

2 minutes ago, Mucka said:

"The ridge part 2" ?

 

 

Certainly an element of de ja veux about the way the post Xmas period is shaping up.

The significant difference in the above, is the lowering of heights over Europe, and the ridge shown to build to our west.

Too much uncertainty at present to call how next week pans out, but a theme is developing and that is for less in the way of trough action and more influence from ridge development, its just unclear how this will manifest, but interesting developments all the same.

[Allseasons-Si]

This is mouthwatering and tantalizingly close to being an epic run

@Atlantic hitting the buffers v's @cold cold heading SW

let the battle commence.

 

[feb1991blizzard]

1996 Feb 5th but with a proper undercut to follow instead of just a slider, blocking better to NE this time.

[Tim Bland]

IS it going under

[SMU]

Perfect shape

[feb1991blizzard]

Just now, Tim Bland said:

IS it going under

 

 

 

100% - no where else to go.

[frosty ground]

The jet get to curve back on this run very late on but the building block are much earlier

[Allseasons-Si]

The cold is winning out here

Choo! Choo!

[Tim Bland]

A BOOM FI  Incoming.....

[bluearmy]

An old fashioned winter pub run ......lubbly !

[Mucka]

11 minutes ago, damianslaw said:

The significant difference in the above, is the lowering of heights over Europe, and the ridge shown to build to our west.

Too much uncertainty at present to call how next week pans out, but a theme is developing and that is for less in the way of trough action and more influence from ridge development, its just unclear how this will manifest, but interesting developments all the same.

Yes we really could do with the ridge being West of the UK but of course this initial ridge was initially modelled to be stronger and further West so let's hope it happens and there is less Atlantic forcing as currently modelled.

Nice to have something possibly developing in the output again.

[Tim Bland]

1 minute ago, bluearmy said:

An old fashioned winter pub run ......lubbly !

What’s the odds then Blue / Steve? Reckon we are in with a chance of this actually coming off? GEFS suite has been hinting at it recently, suppose it was only a matter of time before it showed up on an op run? 

[ICE COLD]

Finally some nice charts . Battle ground in la la land

[feb1991blizzard]

Huge cold pool building to the East and heavy frontal snow across the entire country.

[SMU]

Identical to Feb 1996