Model output discussion - The run up to Christmas

[Kasim Awan]

-7 at 850. Freezing level ~260 metres.. That's potential.

[BlueHedgehog074]

24 minutes ago, AdrianHull said:

Any chance of an uppers output discussion thread mods? 

This is starting to get tedious!

Sounds like we may have to

I suppose we’ll find out though what sort of weather occurs next week in regards to the outlook the models show with the borderline 850 hPa temperatures. But can imagine that while the overall pattern of High Pressure amplifying to our West and Low Pressure dropping over/close to us looks quite likely, suspect their will be more changes to come. Some of which could provide colder 850 hPa temperatures for us. As some say though, 850 hPa temperatures aren’t everything for wintry weather 

Edited December 21, 2020 by DiagonalRedLine

[Penicuikblizzard]

4 minutes ago, Kasim Awan said:

-7 at 850. Freezing level ~260 metres.. That's potential.

Potential certainly but most likely will change on the next run,,,if it’s still there Wednesday then bingo

[Mr snowman 2018]

ECM at 144 make of it what you will !

[Captain Shortwave]

ECM day 6

 

Pretty impressive how tightly clustered the operationals are, even at six days out on an evolution that is not normal for winter. 850s are around -4c, modest but other parameters would draw the freezing level closer to surface level.

Edited December 21, 2020 by Captain Shortwave
Text added

[KTtom]

2 minutes ago, DiagonalRedLine said:

Sounds like we may have to

I suppose we’ll find out though what sort of weather occurs next week in regards to the outlook the models show with the borderline 850 hPa temperatures. But can imagine that while the overall pattern of High Pressure amplifying to our West and Low Pressure dropping over/close to us looks quite likely, suspect their will be more changes to come. Some of which could provide colder 850 hPa temperatures for us. As some say though, 850 hPa aren’t everything for wintry weather 

Dont forget we have to factor in the longer days and stronger sun from tomorrow

[Kasim Awan]

 

1 minute ago, Penicuikblizzard said:

Potential certainly but most likely will change on the next run,,,if it’s still there Wednesday then bingo

All ingredients there for it to develop. 

[V for Very Cold]

O

1 minute ago, Mr snowman 2018 said:

ECM at 144 make of it what you will !

 weather porn?  

[Skullzrulerz]

2 minutes ago, Mr snowman 2018 said:

ECM at 144 make of it what you will !

Polar vortex.... It's not cold enough for widespread snowfall

[Tim Bland]

8 minutes ago, Kasim Awan said:

-7 at 850. Freezing level ~260 metres.. That's potential.

It’s cold enough, but it stays dry unfortunately with any precip in the North Sea. Need winds to back more NE to drive showers inland 

[Allseasons-Si]

All three in unison at 144...

ECM,UKMO,and gfs.

Edited December 21, 2020 by Allseasons-si

[Day 10]

 

Edited December 21, 2020 by Day 10

[BlueHedgehog074]

4 minutes ago, KTtom said:

Dont forget we have to factor in the longer days and stronger sun from tomorrow

Good point, I never thought about that

[Mike Poole]

ECM T168

I’ve noticed a big reduction in posts today, and that is totally understandable.  Lull before the storm!  I think we reached cross model consensus on the broad pattern yesterday afternoon, but it will be a day or two before we can fully understand how cold the air will be, where is at risk of precipitation and whether and when it will be snow.  The shorter range high resolution models will be important but it will be a day or two to get within range.

[I remember Atlantic 252]

6 minutes ago, Mr snowman 2018 said:

ECM at 144 make of it what you will !

around -4, could be enough with low thicknesses, but as always hills favoured

[Mr snowman 2018]

ECM at 168 !

[Howie]

The trough just refuses to budge even a little bit east

[Snowman.]

1 minute ago, Frosty Winter said:

I feel like I’m living in a time warp, whenever I login the first post is always someone moaning about the uppers.

Probably because they're awful for large swathes of the UK.

ECM further west already albeit further south.

Anyone South and East of the low will struggle, especially the rounder it is.

[Kasim Awan]

1 minute ago, Tim Bland said:

It’s cold enough, but it stays dry unfortunately with any precip in the North Sea. Need winds to back more NE to drive showers inland 

The trough would help push it inland. Only taking the odd cm though.

[Chesil View]

1 minute ago, Howie said:

The trough just refuses to budge even a little bit east

The Op is just going through the range of possibilities within the forecast envelope.

[Mr snowman 2018]

ECM at 192 !

[BlueHedgehog074]

8 minutes ago, Allseasons-si said:

All three at 144...

Some great agreement occurring their between the 3 models, albeit with the UKMO the most amplified in the Atlantic. Signs of the upper trough over the UK and Scandinavia being cut off from the area of very low heights and Vortex areas on the opposite side of the Northern Hemisphere. Looking good

(Edit: I agree for the UK area, some additional shifts East or South-East of the Low Pressure would be very welcome)

Edited December 21, 2020 by DiagonalRedLine

[nick sussex]

The frustration over the low not edging sufficiently east is somewhat diluted because there’s still not the level of cold out west or nw initially .

Its likely to need a shortwave to track se to deliver more decent colder 850 values after the initial low has filled .

[Tim Bland]

Snow on 28th similar locations to 06z run...

[TSNWK]

192 worries me.. definite trend across the board for amplification into Greenland to soften.. now do we topple at 216 or head east...