Model output discussion - another cold spell on the horizon?

[sheikhy]

Ecm looks even further west than gfs at 72 hours

[Tim Bland]

5 minutes ago, Allseasons-si said:

I have only just viewed the ECM 00z,...how did i miss that!!! ha ha ha

i do hope the 12z is a lot better than that,...it was sheeeeet!!!!

 

It’s wasn’t all bad..I’d bank the first 7 days

[bluearmy]

The 12z ecm does not bring the front back at all midweek - no trend to back it and more likely just settling to a central point within the envelope 

Edited January 10, 2021 by bluearmy

[sheikhy]

1 minute ago, bluearmy said:

The 12z ecm does not swing the front back at all midweek - no trend to back it and more likely just settling to a central point within the envelope 

Looks slightly further west than gfs blue at 72 hours?

[goosey007]

6 minutes ago, Tim Bland said:

It’s wasn’t all bad..I’d bank the first 7 days

Hi tim,

what are the chances of this correcting west by say 50/100 miles ? Wishful thinking I know

cheers

 

[bluearmy]

Just now, goosey007 said:

Hi tim,

what are the chances of this correcting west by say 50/100 miles ? Wishful thinking I know

cheers

 

I wouldn’t worry about it correcting anywhere until you see the system appear again at 6 days out .....

[goosey007]

6 minutes ago, bluearmy said:

I wouldn’t worry about it correcting anywhere until you see the system appear again at 6 days out .....

ahhhhh fair point

[Purga]

5 minutes ago, bluearmy said:

The 12z ecm does not bring the front back at all midweek - no trend to back it and more likely just settling to a central point within the envelope 

It's better than the 0z - so far.

[sheikhy]

Just now, Purga said:

It's better than the 0z - so far.

Thats what im thinking as well it looks better and further west!!!!not sure wether that front even leaves the uk!?

[bluearmy]

6 minutes ago, Purga said:

It's better than the 0z - so far.

Yes it is ne England and central Scotland as the front stalls further north 

EDIT : and some heading south as the front does back west ....

i expect Tim’s snow map will be out shortly for Thursday into Friday ......

Edited January 10, 2021 by bluearmy

[chris55]

EC and GFS not to dissimilar at day 5 - 120.

 

EDIT, on closer inspection the Atlantic profile is quite different. Im not sure whether its chicken or egg!! Is the Arctic profile forcing its way south.....or are the small lows in the Atlantic pushing their influence north?? You would think in this situation the Artic profile is in charge no matter how many shortwaves pop up!

Edited January 10, 2021 by chris55

[Kasim Awan]

Good evening all. A few days off from the weather scene myself. Feeling hopeful for the rest of the winter given that the past couple of weeks has delivered on que - dozens of snow surprises delivering mostly to high ground & (some) lower elevation areas. The "model shift" which was discussed earlier in the week seems to be ongoing right now, the cause of this is related to the secondary SSW impacts (tropospheric) being inputted as a better-defined data source to the NWP. As this is resolved, so will be the output.

This is not a linear shift - it is characterized by fluctuations as the NWP resolves the next wave of amplification which is likely to be the most defined of Winter 2020/21 so far. From an ensemble forecasting perspective it seems the trend towards a strong Greenland ridge is gaining momentum. 

The model shift, however, is even more defined in the 80 to 150 hour range. Look at the ECM for the 14th from 8th January.

http://www.meteociel.fr/modeles/ecmwf/archives/2021010812/ECM1-144.GIF?12

Compare that to the current output for the 14th:

http://www.meteociel.fr/modeles/ecmwf/runs/2021011012/ECM1-96.GIF?10-0

The significant increase in heights in just 48 hours as a model projection is clear evidence for a background factor being factored in the NWP - and it's impact being modelled. The upshot of this is rather high confidence that the D3+ period will be driven by the SSW downwelling, or at the least a mobile downwelling into rather favourable areas following the initial tropospheric zonal response around the North Atlantic period. This increasing our cold chances into late January quite considerably. Downwelling here is likely to have it's own tropospheric spatial pattern, i.e. move from east to west, a clear migration from Scandi, through the Azores and into Greenland is apparrent from 96h to 216h on some of the output. This is the fruit of that - 

http://modeles.meteociel.fr/modeles/gfs/runs/2021011012/gfs-0-192.png?12

As an outcome this is definitely within reach, this depends on clean high amplification, as per the GFSP this might not be as favourable as it could be. The strong signal for amplification, however, may override any "shortwave issues" etc, due to numerous factors, not only the strong pattern of oscillating bouts of amplification in the past 4 weeks as well as a more favourable downwelling pattern. All in all a very good chance of something very significant - and the synoptic caveats, as discussed, may be an issue however pose less of an issue than in some recent years. This gives us a strong fighting chance. 

Edited January 10, 2021 by Kasim Awan

[Battleground Snow]

We have liftoff with the European Centre for Medium-Range Weather Forecast!

144

 

[BLAST FROM THE PAST]

ECM t168 on 0z
 

t144 on ECM 12z

I think I want 12z, just like UKMO

 

BFTP

Edited January 10, 2021 by BLAST FROM THE PAST

[Allseasons-Si]

The gefs ens full set inc the 850's,...not bad.

[Howie]

The Arctic high seems to be getting bigger and Stronger on every run 

[ICE COLD]

Lift off !!!!!!!!!! 

[Weathizard]

ECM still has the core of heights to our south further East between 96-144 compared to the GFS, going well at 168 though... all roads lead to gold?

Edited January 10, 2021 by Weathizard

[DavidS]

Yes much better at 168

[Johnp]

I was hoping for better at 168 - was expecting the yellows up in to Greenland based on the 144 chart. 

Let's hope the 192 chart locks us in to the cold regime. 

Edited January 10, 2021 by Johnp

[Daniel*]

Decent swathe of country sees rain to snow on Friday before front all sinks south, there’s also heavy snowfall further NE on Wednesday night earlier from same front.

[Tim Bland]

Snow Thursday right down the centre of the UK...

[Cold Winter Night]

1 minute ago, ICE COLD said:

Lift off !!!!!!!!!! 

At +144h I wondered how the rounder shaped Arctic High would change the outcome. Here it gets stretched in the right direction I'd say. It is not far from GFS.
Those lingering heights over France are a pain though. Let's see what happens there +192h.

[Djdazzle]

1 minute ago, Johnp said:

I was hoping for better at 168 - was expecting the yellows up in to Greenland. 

Let's hope the 192 chart locks us in to the cold regime. 

Give it a chance - it’s miles better than this morning’s effort.

[ICE COLD]

Not great at 192