Model Output Discussion - cold spell to end Autumn

[Daniel*]

Snow watch for the S on Monday while Sunday is increasingly appearing to be wet, however this is not a given. GFS 00z develops a secondary low that rapidly depends like UKMO & ECM there could be significant snowfall, isobars are packed tight with blizzard like conditions across the S/E.  

[NO LONGER POSTING]

1 minute ago, Daniel* said:

Snow watch for the S on Monday while Sunday is increasingly appearing to be wet, however this is not a given. GFS 00z develops a secondary low that rapidly depends like UKMO & ECM there could be significant snowfall, isobars are packed tight with blizzard like conditions across the S/E.  

Uppers looks too warm unfortunately loads more runs though!

[Daniel*]

1 minute ago, Surrey said:

Uppers looks too warm unfortunately loads more runs though!

Not quite colder uppers poke their way in. Rain to snow.

[snowking]

^^

The same scenario that 29 of the EPS members were keen on last night too

You have to feel for forecasters right now. If Mondays low does take that track its even more of a headache trying to work out the rain/snow boundary given the incredibly marginal dew points wrapping back around the low 

[NO LONGER POSTING]

Incredible cross model agreement though, need to sort the finer detail out nearer the time and track ECM and GFS almost identical @Daniel*

 

 

 

 

This is why I love weather, you can predict what you see of the charts, but it never ever goes as planned. 

 

You could say that about a lot of things though... 

[shaky]

Gfs gone south again this morning with the snow line!!!gem is a beauty for snow!!all in all snow event for midlands and northern england still on for sunday!!

[tinybill]

this for  57 hr  if  this  comes  off 

[feb1991blizzard]

1 hour ago, CreweCold said:

ARPEGE on Sunday low

https://modeles7.meteociel.fr/modeles/arpege/run/2017120800/arpegeeur-2-60.png?0

Fairly broad agreement across the models so far (may not stay that way obviously).

GEM seems furthest S, GFS furthest N with the likes of the ICON, ARPEGE taking the median track.

JMA + last nights fax further south than GEM.

[SMU]

Morning

The last 24 hours hasnt seen a great deal of deviation on the slider track - some southerly correction, as demonstrated by the UKMO fax charts-

The new deep low shown at 84-96 gives the SE a shot of some heavy snow especially up over the downs !

Looks very interesting!!

edit yes Feb1991 the JMA most southerly run yet

Edited December 8, 2017 by Steve Murr

[shaky]

11 minutes ago, Steve Murr said:

Morning

The last 24 hours hasnt seen a great deal of deviation on the slider track - some southerly correction, as demonstrated by the UKMO fax charts-

The new deep low shown at 84-96 gives the SE a shot of some heavy snow especially up over the downs !

Looks very interesting!!

edit yes Feb1991 the JMA most southerly run yet

Steve what do you make of ukmo for sunday/monday!!continues from 12z last night!!doesnt look like its pushed any further north with the slider and dont look as deep either!!

[SMU]

14 hours ago, shaky said:

The midlands gets a pounding on the ukmo 12z!!with the gfs going south aswell its a good start steve!!

Hi shaky my quote is you from 13 hours ago lol its stuck

no northward progression-  ECM identical to JMA at 48

Thats a worry for many as thats a big step south...

Edited December 8, 2017 by Steve Murr

[Bricriu]

1 minute ago, Steve Murr said:

Hi shaky my quote is you from 13 hours ago lol its stuck

no northward progression-  ECM identical to JMA at 48

Thats a worry for many as thats a big step south...

If it goes south is that not better for those of us who are further south?

[shaky]

5 minutes ago, Steve Murr said:

Hi shaky my quote is you from 13 hours ago lol its stuck

no northward progression-  ECM identical to JMA at 48

Thats a worry for many as thats a big step south...

Yes steve ecm much further south lol!!you could not make this up  lol!!low not as deep compared with the 96 hour chart from yesterday morning!!

[SMU]

16 minutes ago, shaky said:

Yes steve ecm much further south lol!!you could not make this up  lol!!low not as deep compared with the 96 hour chart from yesterday morning!!

Wait for the 96 - its deepening!!

whilst we have no 60 chart the 850s are in the same location at 48 -infact identical with no intrusion of the 0c isotherm.

London still in the game for sunday!

[SMU]

The 84 chart would look great for the SE - with the low sliding up the channel !

poss snow event in the making!

[ArHu3]

20 minutes ago, shaky said:

Steve what do you make of ukmo for sunday/monday!!continues from 12z last night!!doesnt look like its pushed any further north with the slider and dont look as deep either!!

 

31 minutes ago, Steve Murr said:

Morning

The last 24 hours hasnt seen a great deal of deviation on the slider track - some southerly correction, as demonstrated by the UKMO fax charts-

The new deep low shown at 84-96 gives the SE a shot of some heavy snow especially up over the downs !

Looks very interesting!!

edit yes Feb1991 the JMA most southerly run yet

Hirlam 0z also shows a lot more snow for the Netherlands compared to 18z's rainy output, confirming a more southerly path

[SMU]

18 minutes ago, ArHu3 said:

 

Hirlam 0z also shows a lot more snow for the Netherlands compared to 18z's rainy output, confirming a more southerly path

Any chance of pic- I can only see to T48-

[Retron]

9 minutes ago, Steve Murr said:

whilst we have no 60 chart the 850s are in the same location at 48 -infact identical with no intrusion of the 0c isotherm.

We do have one, thanks to weather.us:

https://weather.us/model-charts/euro/2017120800/great-britain/temperature-925mb/20171210-1200z.html

(That has pretty much all the parameters, in 3-hourly intervals)

[Daniel*]

ECM 00z shifts the snow line S it wouldn’t overly surprise me if Greater London gets amongst this. 

 

 

 

[SMU]

42 minutes ago, Retron said:

We do have one, thanks to weather.us:

https://weather.us/model-charts/euro/2017120800/great-britain/temperature-925mb/20171210-1200z.html

(That has pretty much all the parameters, in 3-hourly intervals)

Cheers

just north of London then ! @Retron  but edging south - first run with snow in NW kent from the slider

Edited December 8, 2017 by Steve Murr

[NO LONGER POSTING]

Southerly correction occurring? Or a dodgy run? All I know is, its VERY exciting times 

 

[bluearmy]

Note the warm front ahead of the occlusion on the latest FAX charts. that looks significant to me and reminiscent of times past - wait to see if the met office forecasts change because of it, taking the snow line further north than the occlusion 

the snow line in se uk has ramifications for mondays system which could bring more snowfall. If Sunday night has snow on the ground then that system brings its precip into much colder air than if it doesn't . 

Edited December 8, 2017 by bluearmy

[feb1991blizzard]

ECM awful run apart from the midlands dumping, looking like whoever gets snow should make the most of it as chances look diminished for a good while after this.

[bluearmy]

And looking at the gefs NH profile we continue to see Stewart's thoughts being played out with the p/v beginning to drift west and the n Pacific ridge re establishing rather closer to the aleutians 

[pureasthedriven]

21 minutes ago, Daniel* said:

ECM 00z shifts the snow line S it wouldn’t overly surprise me if Greater London gets amongst this. 

 

 

 

Chimes with regional METo update.