Model output discussion - Jan 3rd onwards

[Trom]

12 minutes ago, Vikos said:

Just the amount of clusters shows the uncertainty very good. I think we need to give it just some more days, by weekend there should be a better prospect of today’s ssw in the charts. It happened just now and we don’t know what outcome it will have, split or displacement. That are huge differences to be calculated...

Yes all a bit despondent in here tonight and I'm not really sure why.  Some good posts showing how the models failed to get a grip on 2013 and 2018 at this range.  Also some really good indications of cold to our east.  No two SSW are the same and given we've only really been looking at them seriously very recently there is a lack of training data for the models, which in turn makes any mid-long range forecasts dubious at best right now.  This is an important point - without training data i.e. enough evidence of how multiple SSW have unfolded in the past you can't train the algorithm to predict with any reliability.  This should get better over time but remember they are still rare events.

I've been encouraged by seeing strat models pushing the vortex over Asia and the Atlantic initially but then pushing the real cold back to Europe later on. 

As yet nothing we can pin our hats on but very much all still to play for!  Keep those fingers crossed.

[Allseasons-Si]

Evening all,and really late to the party with all the reading in here and in other threads and sites

i am focusing on the day ten EPS for now as this shows some subtle shifts in the pattern that could favor us down the line

i have done a complete Mozart of a Nick sussex special on this and here goes:-

here is the EPS from this evening v's the 1st Jan(obviously diff dates) but i will explain below...

 

1,is the placement of the trop pv(red circle) and it is starting to move from its semi-permanent position over eastern Asia to central Asia and into Europe thanks to the west Russia hp cell that also has been a semi-permanent feature since late Autumn/early winter and not allowing any influence of the Siberian train backing W/SW into Europe (black arrow with green X)

2,as this hp cell retreats south over southern Asia it allows lower height's to flood in from Siberia west/southwest through central Asia and into Europe(green tick)

3,whilst maintaining height's over the north pole this is a good situation that we could be in with the blue line i have drawn from our meridian to the far northeast of Siberia and anything west of that clearly showing height's and the lack of westerly momentum in a zonal flow

we are starting to see evidence of this in the models now over the past day or so with the reappearance of an Atlantic ridge and if we can get this ridge to punch further north then that Siberian train is waiting to pounce.

you can see the change as regards to that ridge i have discussed above and in the latest cpc anomalies it removes this also in the extended 8-14

 

Later's .

[PiscesStar]

4 hours ago, Scandinavian High. said:

Don’t worry if do get beast from east we in SE. / east anglia will be laughing .

I won't. Bring it on. fully on.... 

[Cheshire Freeze]

If the Atlantic loses any more momentum we'll be in an easterly next week

[Battleground Snow]

44 minutes ago, CreweCold said:

If the Atlantic loses any more momentum we'll be in an easterly next week

Indeed, models are still toying with the amplification up through the UK, Let's see if the ECM can repeat yesterdays run.

Para and gem at 240

 

Edited January 6, 2021 by Battleground Snow

[swfc]

Morning. After viewing yesterday's 12z on all models got up expecting this place to be buzzing. That said after yesterday's earlier output then the euphoria later another swing was always possible. The fluidity continues really as over the last view days with many options on the table imo. Interesting watching the nhp, sww, wind reversell and the merry dance the PV is being given. Hopefully things become a bit clearer heading into the weekend, next week. Stay safe

Edited January 6, 2021 by swfc

[Battleground Snow]

GFS and Icon EU still seeing some snow for early hours Friday. Perhaps a little over the top, but maybe a dusting for some.

 

[Battleground Snow]

Para ends on an interesting note, a repeating theme of WAA up through the UK. We may need a few attempts of this to split the trop vortex in 2? 

Hopefully the ongoing strat warmings can assist with this

 

[That ECM]

An improvement in the mean I would suggest.

[northwestsnow]

UKMO looks slightly more amplified af 144 .

If we could nuke the low to the left on this chart we would be in business ...

 

[northwestsnow]

GEM looks similar to UKMO at 144 and day 10 has some potential...

Edited January 6, 2021 by northwestsnow

[northwestsnow]

120.. 

Which way does it go.....

[northwestsnow]

Not liking 144...

 

Much prefer UKMO...

[Mucka]

Okay, I am going to do the opposite of what I should be doing and that is analyse deepest FI when we have a chance of snow on our doorsteps in the coming days. Lockdown madness.

A few days back when we were still looking good for maintaining cold and blocking I talked about the chance of deep cold around mid month with the PV (LP) pushing SW and a deep trough developing over Scandinavia.

Well when the pattern flattened that was a bust for around mid month but we are still going to get that chunk of PV moving SW in FI and if the pattern can reamplify enough and blocking be favourable (if, if if) then that scenario is still a decent possibility just delayed into last 3rd of the month. Something like this.

Either way it looks like the 2nd half of January will have the UK as the battleground between the frigid airmass attempting to push SW and the milder Westerlies attempting to push NE.

That could mean a lot of snow where the two airmasses meet but will that be over the continent and scandi or over the UK?

Edited January 6, 2021 by Mucka

[That ECM]

10 minutes ago, northwestsnow said:

Not liking 144...

 

Much prefer UKMO...

Still prefer it?

to be fair similar but ecm just a bit slower.

[Mucka]

12 minutes ago, northwestsnow said:

Not liking 144...

 

Much prefer UKMO...

Bit of a let-down after the 12z but that looked to good too be true at the time.

Edited January 6, 2021 by Mucka

[northwestsnow]

Big -AO on EC 00z..

Atlantic sector looks horrid though...

[TSNWK]

ECM removes the teeze from last night sadly. 

[northwestsnow]

Dont even feel like posting day 9 its that bad.

I'm sticking with UKMO !!

[Penicuikblizzard]

I think we are going to end up in the middle unfortunately, frigid air in the states and frigid air to the east of the UK, we will have a mild high pressure sitting over us for a few weeks,,,,,,very much a unscientific prediction as I have don’t have much knowledge on the charts but let’s see if I’m correct

[Severe Siberian icy blast]

7 minutes ago, TSNWK said:

ECM removes the teeze from last night sadly. 

Compare 12z with the 12z and 0z with the 0z, 

It's a huge improvement, we've got wedges of high pressure, a tanking neg ao, and no vortex over this side of the hemisphere, I think by tomorrow morning it'l look much better and this evenings will be an improvement again 

[booferking]

Icon 120hr never mind day 10 all models are slowing the Atlantic down alot earlier one to watch.

[That ECM]

For all those that say day 10 is always great blah blah well not always

[cyclonic happiness]

1 minute ago, Severe Siberian icy blast said:

Compare 12z with the 12z and 0z with the 0z, 

It's a huge improvement, we've got wedges of high pressure, a tanking neg ao, and no vortex over this side of the hemisphere, I think by tomorrow morning it'l look much better and this evenings will be an improvement again 

I've just had a look at the GFS (no others yet) and I think you're right!!  It looks a whole lot better than the last couple of days, I think there's a swing back towards colder weather and away from southwesterlies.  However the pendulum has only just started to swing back.

Also,it's snowing here?? in the east midlands??? and heavily???

[SLEETY]

Wretched ecm after last night's run, couldn't be more different, with Azores high the main player, hopefully it's a mild outlier after 168 hours like it has been recently or its miles away from cold at the end, inconsistent model it is becoming!