Model output discussion - Into 2021

[Harsh Climate]

Nice ECM 120. Hopefully gfs is having a wobbly.

[Kentspur]

Lovely ECM for 09/01 looks like its about to line up an Easterly with minus 8c to minus 9c uppers finally over the SE/EA

Edited January 2, 2021 by Kentspur

[That ECM]

T144 all 3. ECM has changed quite a lot from its previous run. Some will say not as good, some will say it’s getting it self in a better position. 

[Cheshire Freeze]

UKMO best by far this morning- not even close.

ECM is just meh. Cold surface but toppling pattern and high thicknesses going forward meaning cold and dry. 

Looks to me like we are going to have to endure a topple pattern for a while. Not ideal when wasting prime winter time.

Mildest GEFS mean I've seen in a long time in FI- looks like USA getting the cold air displacement there

Edited January 2, 2021 by CreweCold

[Sky Full]

I am concentrating on the 7th January for the moment as this seems to be the date after which the trend could go either way - towards even colder conditions or gradually milder.   Here are this mornings charts for +120 hr....

                                     500s.                           850s

UKMO    

ECM        

GFS         

GEM.      

 

The low pressure to the north is likely to move south and could introduce colder easterly winds than we have had so far.   There is plenty of cold air in the vicinity but it needs to move in our direction to bring proper wintery conditions.  Alternatively, the Atlantic high could retreat and allow westerlies to return.  I don’t think anyone can be completely confident about the outcome just yet.

[swfc]

5 minutes ago, That ECM said:

T144 all 3. ECM has changed quite a lot from its previous run. Some will say not as good, some will say it’s getting it self in a better position. 

Yes things are on the change somewhat. That said isn't it generally the case on the nhp and models has the timescale closes in anytime of year. Yesterday's snow predictions in fi are becoming a bit tiresome along with snowmaggedon @ my street. Still a cold outlook "wintryness" to be decided ete but nothing zonal shown as such. Hopefully the projected waining "if it happens" is short lived but nothing has happened yet anyway. Projected ssw still in the pipeline so positives heading threw January along with areas of higher Heighths still visible on the models

[Kentspur]

The ECM ends with milder upper air conditions for all spreading down from the North/West but not before delivering the possibility of a cheeky "snow starved SE" snow showers affair with minus 8-9c uppers for 3consecutive days and an Easterly off of an increasingly cold mainland Europe 

Edited January 2, 2021 by Kentspur

[KTtom]

6 minutes ago, CreweCold said:

UKMO best by far this morning- not even close.

ECM is just meh. Cold surface but toppling pattern and high thicknesses going forward meaning cold and dry. 

Looks to me like we are going to have to endure a topple pattern for a while. Not ideal when wasting prime winter time.

UKMO still gives hope, but as the other 2 look fairly similar, the summing up is looking the likely outcome. The vortex is hanging on to northern Greenland by its finger nails, just needs 1 more kick !

Edited January 2, 2021 by KTtom

[Cheshire Freeze]

3 minutes ago, KTtom said:

UKMO still gives hope, but as the other 2 look fairly similar, the summing up is looking the likely outcome. The vortex is hanging on to northern Greenland by its finger nails, just needs 1 more kick !

I suspect the next period of interest will be circa 20th Jan onwards. Cold latter third of month looks likely to me.

[Radiating Dendrite]

1 minute ago, CreweCold said:

I suspect the next period of interest will be circa 20th Jan onwards. Cold latter third of month looks likely to me.

Day 20 now instead of 10.

This is starting to feel like the wizard of oz.

[Weather-history]

Is the problem for the models, that there is nothing really on our side of the hemisphere to drive these weather patterns? 

Wetterzentrale shows it well. ECM 240 hr chart, hardly any deep blues and purples. 

[Cheshire Freeze]

5 minutes ago, Radiating Dendrite said:

Day 20 now instead of 10.

This is starting to feel like the wizard of oz.

Well the relaxing of the pattern has been well advertised in the longer range products for around the middle third of the month. It's a possibility that the SSW has disrupted the pattern we were in.

I'm no strat expert but I would suggest that we're seeing the models are showing coupling of the strat and trop and the flush down of the remaining westerlys. Hence the flattening. This shouldn't last too long in all honesty.

Hard to see how the trop doesn't go into reversal circa 3 weeks or so from now though. On balance, I'd say it's more likely than not the beast of Siberia will come to pay us a visit. Obviously the MetOffice are seeing along similar lines (at least the risk of) with their longer range forecast for later January.

Edited January 2, 2021 by CreweCold

[swfc]

Bit of a straw clutch but the gem at day ten still looks very positive. I know, but maybe a hope

[Frosty.]

Has anyone mentioned the GEM 0z?...IMO it’s a GEM   ️ 

 

Edited January 2, 2021 by Jon Snow

[Griff]

Para is fine, go chill in the snaw....

[Ali1977]

Those who think there isn’t much snow in the charts next eeek look at this, in 2 hours some pretty intense snowfall has appeared out of nowhere in the NE - not sure how but it’s happened abd it’s very cold there so will certainly lie.
 

[Duane S.]

Ukmo again goes from zero  to hero with the best D6 output of the morning

ECM is good but goes on to produce another completed different D10 chart (nothing particularly new there though). Energy running over the top appears to be the main spoiler on this one (but it’s still a lovely winter chart though!), Difficult to know where it would be heading next. Not that it matters of course, as it is very unlikely to be right at that point anyway.

I appreciate there is 12 and 24 hours difference but just to show how all over the place the output is, in particular for our neck of the woods, the last 3 D10  ECMs.

 

What is consistent is the main vortex edging further Northeast, as expected. SSW coming very soon, I can’t imagine the output is going to stabilise for quite a while yet. I think it is probably worth steering away from the GFS long term trop charts for a while, they won’t be able to get as good a grip on the impacts of stratospheric events above.

And anyway, there will be plenty of opportunities next week for most, so no need to be downbeat on the back of a couple of slightly less good runs. This remains terrific model watching

[Kentspur]

How well will the models factor in the drop off in North Sea SST's over the next 10days between East Anglia and the low countries especially to determine any precip type forecast from the east? It looks like going several degrees colder between now and 11th January according to ECM data

[Battleground Snow]

ECM looks like it will be an outlier in terms of 500mb pressure for 144 based on the mean here at 144

Who do you back at 120 ECM or Ukmo?

Para has been rock solid with many runs for this.

The GEFS do advertise a warm up of sorts past day 12, but this isn't set in stone. Let's see if the extended EPS continue with this theme. If we can get the high to topple into scandi we could potentially have a longer period of cold before the pattern relaxes.

 

[That ECM]

5 minutes ago, Battleground Snow said:

ECM looks like it will be an outlier in terms of 500mb pressure for 144 based on the mean here at 144

Who do you back at 120 ECM or Ukmo?

Para has been rock solid with many runs for this.

The GEFS do advertise a warm up of sorts past day 12, but this isn't set in stone. Let's see if the extended EPS continue with this theme. If we can get the high to topple into scandi we could potentially have a longer period of cold before the pattern relaxes.

 

Not far off the mean at T144. It’s T192 and on. To be honest, I can’t see the high going to scandi. Not seen that on any output but may have missed it.

Edited January 2, 2021 by That ECM

[Battleground Snow]

12 minutes ago, That ECM said:

Not far off the mean at T144. It’s T192 and on.

It's doesn't look that far off, but it's this period which has the key difference in the models in terms of the low placement.

There is a 300-400 mile difference in terms of the heights into Greenland

Re- the Scandi high, Steve mentioned a surface high in that area on the para around 240 hours, but it didn't last long.

Edited January 2, 2021 by Battleground Snow

[IDO]

No need to panic yet, the trend from the gfs op is to flatten the pattern for a few runs, but looking at the d10 gefs and nothing has really changed, still plenty of entropy as how the ridge/trough combo is handled:

The ecm has swung to another possibility this morning which is no surprise as its d10 chart from last night was standard ecm bias at that range. It was OTT with its development of the Arctic high and now by d10 is similar with the gfs op. We have to expect issues with the SSWE fed by the algorithms early that will change as the data reflects a slower or faster response? The flatter route, but maybe by d12 would be a fair call.

JFF and what we can see from the gefs at d16:

Some interesting stuff there^^^

London>d16 mean>

Looking at the London ens and a clear signal ATM for less cold by d16. The mean upper temps suggest the core cold on the Asia side and the axis of cold takes the severe cold to N America. If that is the setup, and this has been a continuous trend for the tPV, then when the music stops, the UK will probably need an easterly to benefit from the trop response initially? Otherwise scraps of cold yet again!

Interesting 10+ days ahead and hopefully some snow!

[nick sussex]

Some wild swings in the outputs post day 6 . 

Scarcely believable change from the ECM from last nights 12hrs run so clearly drawing concrete conclusions as to which evolution is correct seems a bit premature .

Sometimes the models are unable to handle all the background noise as in the SSW . 

I see nothing to be overly concerned about this morning from a coldies perspective.

I think we need a few more days to see what the real impact of the SSW will be.

Edited January 2, 2021 by nick sussex

[carinthian]

Morning all a few mixed signals coming from GFS and ECM this morning. However, UKMO remains rock solid towards a prolonged and increasingly colder spell for many. Of all the models over the past 5 days , UKMO has shown consistency out at 144t. Should have an update later today from the team once they have digested the charts after their New Year break.

C

Edited January 2, 2021 by carinthian

[winterof79]

Nice // today along with UKMO