Model Output Discussion - cold spell to end Autumn

[Zakos]

Cold shot, cold reload, then a battleground scenario as the atlantic tries to make inroads. A recurring theme in the output, and the most likely scenario IMO

What more could you want! fantastic model watching.

Little evidence for a return to atlantic conditions.

I for one am ecstatic that cold is on its way, and we are not constantly looking for glimmers of hope in charts 10 days out.

What we would have given for a chart like this last season.it's only 54 hours away! and it's not even winter yet.

very exciting times ahead I feel

[Summer Sun]

The GFS 12z Op is all over the place from Saturday fluctuating colder and warmer than the mean overall the outlook from the mean hasn't changed with temps remaining below average until at least mid Dec

 

[northwestsnow]

Cracking GEFS

[chris55]

Colder trend around the 5th onwards is gaining support on the GEFS 12z -

London ens

 

 

Edited November 27, 2017 by chris55

[Ali1977]

It looks likely after a chilly week this week something properly cold will begin at day 8. If correct the difference in day time/850s  temps between this week and next should allow for snow to fall pretty much anywhere, just dependant on wind direction NNW/NNE as to where they come from and penetrate too. Frosts pretty much anywhere, although not severe down south with the stronger winds. Any fronts within the flow could bring more meaningful falls, these would lie (especially at night or at altitude....All in all it's looking good, the problem is 8 days is along way away in UK weather forecasting!! 

[Snowy L]

Worrying that Spain remains a low-pressure free zone still. Incredible how low pressure systems suddenly disintegrate as they travel towards Spain. We need low pressure there for a sustained block.

Edited November 27, 2017 by Snowy L

[Cheshire Freeze]

4 minutes ago, Snowy L said:

Worrying that Spain remains a low-pressure free zone still. Incredible how low pressure systems suddenly disintegrate as they travel towards Spain. We need low pressure there for a sustained block.

Yes, persistent HP in and around that locale has been noted by others on here and on other forums.

[northwestsnow]

 

Liking the look of EC 96

digs the trough a little further South west than gfs at same time

Edited November 27, 2017 by northwestsnow

[karlos1983]

Up up and away 

ecm looking good at 120, steady as she goes.

 

[radiohead]

High is a bit further south and east on the ECM compared to the GFS at T144

[northwestsnow]

Squeeky bum time at 144- is she going to sink????

[Summer Sun]

ECM appears to have the 'highest' 850's of the main 3 at t144

[bluearmy]

different profile off the eastern seaboard day 6 - less developed low on the 12z - should make a difference to day 7 upstream

EDIT: small upper cold pool comes across and deepens that little low so looks like its pretty good consistency after all. now what happens to the 'no longer cut off low' day 8 ??

Edited November 27, 2017 by bluearmy

[Cheshire Freeze]

Just now, northwestsnow said:

Squeeky bum time at 144- is she going to sink????

To me it looks likely that some heights will sink away, with just enough WAA north to promote the HP around Greenland. It's a messy scenario though and is why the evolution has been pushed back 24-48 hrs on last night's offerings. We could do without the heights leaking back S though as it adds further complications down the line...but it is what it is.

[karlos1983]

3 minutes ago, northwestsnow said:

Squeeky bum time at 144- is she going to sink????

If she does she’s a rogue, if she doesn’t she’s a hero 

[MP-R]

22 minutes ago, Snowy L said:

Worrying that Spain remains a low-pressure free zone still. Incredible how low pressure systems suddenly disintegrate as they travel towards Spain. We need low pressure there for a sustained block.

Yes, and they could really do with some rain down there. Friends of mine in Madrid and Zaragoza have commented how unusually dry it's been.

[Daniel*]

Eye-watering not in the bad sense AO forecast blocking in the high latitudes is going to a common feature for the foreseeable highly uncommon for early December, poor school boy bully vortex. Nope, it deserve a right kicking!  

[Cheshire Freeze]

Core of the blocking now to our SW...

We don't want to see any more of this type of thing really as we'll be talking more about a S'ly than a N'ly!

[northwestsnow]

High is a sinking, getting perilously close to a west based -NAO here imho.

[Ali1977]

ECM 168 looking very good, to me it's looking better than the GFS thus far although may delay a day. We shall see

Edited November 27, 2017 by Ali1977

[tight isobar]

Becoming a bit of a headache..

As height spread across iberia becoming stedfast...

However ec-looking for a way to greenland.

And overal promising as a whole!

[winterof79]

2 minutes ago, Daniel* said:

Eye-watering not in the bad sense AO forecast blocking in the high latitudes is going to a common feature for the foreseeable highly uncommon for early December, poor school boy bully vortex. Nope, it deserve a right kicking!  

Quite astounding tanking.I wonder when was the last time during winter it did that for such length 

[I remember Atlantic 252]

3 minutes ago, CreweCold said:

Core of the blocking now to our SW...

We don't want to see any more of this type of thing really as we'll be talking more about a S'ly than a N'ly!

Hopefully not like GEM, with shorts/summer clothing out

Edited November 27, 2017 by I remember Atlantic 252

[tight isobar]

2 minutes ago, I remember Atlantic 252 said:

Hopefully not like GEM, with shorts/summer clothing out

A little concerning that the gem' is smelling this signal!

And ecm has hints also!!!

[Cheshire Freeze]

Never simple for the UK is it??

This what happens when you can't get the core of heights far enough N. What's worrying is that closer to T0, the models seem to adjust heights upwards over Iberia...a common theme over the past few years.