Model output discussion - 1st December onwards

[Nouska]

3 minutes ago, bluearmy said:

upstream isn't going to look like that though nouska. 

 

 

 

 

I was just answering the question in Twitter...

Btw, do you know of any other Jan with a monster Kara High as, strong

....not looking at specifics for now.

 

[BlueHedgehog074]

ECMWF used as an example but, essentially, the models continue to play about with a block to our North East.

(for the sake of those to the North-West, though, seeing the block trying to extend far enough South and West over UK/Northern UK would be welcomed, I'd imagine. But while the trends are to see that Russian or Scandinavian blocking, there is some uncertainty regarding how well the Atlantic Lows could disrupt/undercut against the block, or also how far South they could track through the UK. How far North or South. How far North or South they track towards the UK could mean the difference between a flow from the East or a flow from the West. Although both scenarios do have the possibilities of producing some chilly weather at times).

[phil nw.]

Just looking the 06z gefs stamps at day 7 and they are pointing to trough disruption around the UK as the Atlantic jet is split.

Some quite intersting ones with quite a number showing trough extension into Europe

obviously they are open to interpretation but if we can get some low pressure down into the Med this will help to pull the cold out east towards us later.

This battleground scenario has some days to run yet i think but as long as that strong ht anomaly remains to our NE then we stay in the game as the Atlantic jet will have to split somewhere around these parts.

The only downside of course is the likelhood of more troublesome rain for some areas already suffering as the fronts start to stall against the block.

 

[snowking]

Just taking a bit of a closer look at the ECM ensembles from the 0z suite, a couple of things to note.

Firstly there is a cluster in the longer term that develops more significant blocking to the North of the UK - closer than the currently modelled Scrussian high and certainly close enough to influence our shorter-term climate. Not too different to a number of the GEFS members at such range, like this:

It's worth noting though this is comprised of 13 members vs the 24 or so members which comprise the biggest cluster.

To follow on from this, however, the largest cluster does build heights Northwards directly through the UK out towards day 15, a little like this:

So taking things completely at face value chances of some sort of blocking influencing the UK beyond week 1 of January at least from the 0z run look fairly good. No surprises, however, therefore to see from the 0z GEFS where the biggest spread takes place:

But perhaps most strikingly, by just day 3 there are 6 clusters on the 0z suite - so anyone hoping for clarity from ensemble suites right now will be left a little disappointed.

There's still nothing at this stage which suggests to me that we are in for anything major in the shorter term cold wise, with a few marginal snow events looking the most likely scenario as troughing attempts to disrupt close to our shores. Of course our shores are rather limited longitudinally and given the potential margin for error in modelling such scenarios in the medium term and extraneous factors such as the unseasonable warmth across much of NW Europe at the moment, we might struggle this time around for anything too exceptional at this stage. Later in the month though, given the continued pressure on vortex into the medium range, could be another matter entirely:

SK

 

[MR EXTREMES]

id be inclined to bin the gfs atm really is struggling with the pattern mjo super el nino feedback.

I see a slow burner and the models recently have really started to show real changes afoot but the gfs 6z to my eyes is blooming messy but then so are the rest but the ecm ukmo have the scandi heights trying to retrogress towards Iceland Greenland perhaps in the end.

allowing a real neg nao ao not west based either.

I think theres certainly something brewing

[SMU]

Significant improvement at 120 on the UKMO

much much better allignment of the cold across europe - more westserly component

144 should be the first visibility of the UKMO interpretation of the undercut

s

[snowice]

Just now, THE CHOSEN ONE said:

Significant improvement at 120 on the UKMO

much much better allignment of the cold across europe - more westserly component

144 should be the first visibility of the UKMO interpretation of the undercut

s

Gfs not looking great?

[Eskimo]

41 minutes ago, emotional rollercoaster said:

id be inclined to bin the gfs atm really is struggling with the pattern mjo super el nino feedback.

I see a slow burner and the models recently have really started to show real changes afoot but the gfs 6z to my eyes is blooming messy but then so are the rest but the ecm ukmo have the scandi heights trying to retrogress towards Iceland Greenland perhaps in the end.

allowing a real neg nao ao not west based either.

I think theres certainly something brewing

Really? At least the high is further north and stronger. 

[seabreeze86]

UKMO going for the undercut/slider i think

GFS not having it though, Will the ECM side with the GFS or the UKMO mmmm

[Captain Shortwave]

UKMO is probably the chart of the winter so far considering the timeframe.

The low will move across the south west quarter of the UK with the potential to drag the cold pool straight westwards.

The GFS on the other hand is a poor with westerlies resuming after about one day of trough disruption on the 2nd.

You wouldn't trust either at the moment to be honest, but at least the cold option is still on the table tonight.

GEM at day 6

I have to laugh at the GEM, it goes wrong so quickly with regards to the cold pool that you end up with a second go at shunting the cold pool west..... Then it goes wrong again 

Edited December 28, 2015 by Captain Shortwave

[Aaki Khan]

UKMO Undercut On The Way!

[Iceberg]

Gfs with a 20mb difference in the North Sea at t168 compared with its 06z

Its still struggling with energy. Saying that thought it's a significant improvement on the 06z with a much better jet angle and far less building of the high to the north, just too much energy and a further step towards Ec/met needed for the correct under cut just after new year 

Edited December 28, 2015 by Iceberg

[northwestsnow]

Ohhhh im liking UKMO this evening.Shirley an undercut will follow on from 144..

[KyleHenry]

21 minutes ago, THE CHOSEN ONE said:

Significant improvement at 120 on the UKMO

much much better allignment of the cold across europe - more westserly component

144 should be the first visibility of the UKMO interpretation of the undercut

s

This passage of phases has a look of a 2 day glancing blow of -8C 850 mb line to East Coast of UK especially E coast of Scotland.

Are we agreed that of most importance is that the Kara HP survives and holds. 

It will allow retrogression to enable -AO and within 14 days a structured -NAO and all that follows regarding extended cold period for entire UK. 

What is certain for next 14 days is a +NAO under a colder NW air stream and heavy rainfall to NW and SW UK coasts. 

Edited December 28, 2015 by KyleHenry

[Troubleatmill]

one thing the GFS does have though is a good orientation of azores high, heading NW to SE giving greater chances of these atlantic lows to dive SE, as long as we keep pressure  high to Scandi one of  these lows will dive under

[northwestsnow]

GFS looking much better longer term - huge improvement on the 6z with the jet sinking and sinking.

[shaky]

Much much better gfs than the last couple of runs!!!!ukmo is an absolute blinder!!!would expect a january 17th 2013 event out of that undercut and we all know how much snow that dumped across wales midlands and southern england!!!i smell a gfs backtrack maybe!!if ecm sticks to the undercut scenario then its haply days!!

[Cloud 10]

Quite a corker from the UKMO this evening,and the first mention of "colder and drier in the East" from their week 2 forecast.

 

A real freefall (tom petty anyone?) in the AO coming up and i look forward to Cohen's next blog update.

 

Edited December 28, 2015 by Cloud 10

[knocker]

The next wet and windy belt after midweek evening Friday

Edited December 28, 2015 by knocker

[nick sussex]

The GFS taking over the Scrooge role but still angles the jet se'wards and displaces the Azores high.

The UKMO is excellent with the negatively tilted troughing at T144hrs and high pressure further west. The best chart by miles of the winter so far.

[Carlrg]

Is there any chance of that system being a glancing blow Knocker or is it a definite wipeout.

EDIT: Thanks for the reply.

Very worrying really, we already have numerous roads closed  around here already. We need a few weeks to dry out.

Edited December 28, 2015 by Carlrg

[Froze were the Days]

GFS still not showing any real cold, yes somewhat of a jet developing well to the south @10 days but the problem is that there are lower heights to our north and north west as well so no real cold but not mild either...still take UKMO and the undercutting solution but what is troublesome is the little developing low behind which would shunt the trough through the UK (I would imagine) if there was a 168 chart.

Edited December 28, 2015 by Froze were the Days

[knocker]

5 minutes ago, Carlrg said:

Is there any chance of that system being a glancing blow Knocker or is it a definite wipeout.

A distinct possibility the depression itself will pass to the NE although the associated fronts will cross the UK and it will still be windy. But there is more in the pipeline I'm afraid.

Edited December 28, 2015 by knocker

[Iceberg]

Gfs and met comparisons at t144, Ec will be interesting for t144 when it comes in at 6.30ish

[nick sussex]

1 minute ago, Froze were the Days said:

GFS still not showing any real cold, yes somewhat of a jet developing well to the south but the problem is that their are lower heights to our north and north west as well so no real cold but not mild either...still take UKMO and the undercutting solution but what is troublesome is the little developing low behind which would shunt the trough through the UK (I would imagine) if there was a 168 chart.

That low would disrupt aswell , theres no chance that will cause any problems as it will run in and head se'wards.