The hunt for cold - Model discussion (late November)

[BLAST FROM THE PAST]

5 minutes ago, draztik said:

Probably best not to be looking for that type of cold in the UK, tho? Well, that’s if we are being realistic? 

In late November we were told to expect this forum to be hyper busy into 2nd wk of December (due to possibility of severe cold)... then it was pushed back to Christmas. Now we are talking about early January & beyond .... 

A definite and all too familiar theme. 

It’s pretty cold and only 15 days into the meteorological winter (some will enjoy next 24-36 hours), astronomical winter hasn’t started.  It could be better agreed, but could be a lot worse too.  

 

BFTP

[booferking]

4 minutes ago, BLAST FROM THE PAST said:

Hunt for cold......go outside right now.....It is very cold and has been cold for a few days....that’s realism Frosty.

I think folk are hunting prolonged (week+) of sub zero days......?  

 

BFTP

It's cold here alright but not the nice type 5c lashing down & wind howling here not a nice day at all we have a weather warning for up to 50mm of rain & 60mph gust today not nice at all.

Christmas miracle not over yet even a fleeting northerly will do me fine before the main event.

[Seasonality]

And the 6z is already off on a different path. 

[Nick F]

Quick one from me this morning, as Netweather's daily FP forecast taken more time than usual with Storm Deirdre arriving. I know we are looking for the next cold, but today looks potentially nasty for the north later with regards to severe winter hazards, with heavy snow / blizzard conditions, but perhaps more of concern the rare threat of freezing rain over higher ground, as a less cold layer (above 0C) moves in aloft and melts snow falling through this layer into super-cooled rain - which then hits the ground level still 0C and freezes into ice on contact with frozen surfaces. Take care those up north and try not to travel too far if necessary!

Back to the models, expect a lot of model volatility related to the stratosphere PV being displaced and its impacts on the upper trop. Operationals not really in line with the EPS z500 means for day 10 (25th) - with the EPS mean showing +ve heights anomaly / ridging signal mid-Atlantic. GEFS mean was flatter however at day 10. Big uncertainty...

Edited December 15, 2018 by Nick F

[fromey]

Morning all, i think some have short memory's, ive spent the last hour going through the archive from January/February looking at charts and comments leading up to the beast from the east 2018 and its laughable how similar they look with regards to comments and charts.

Looking at the charts the ECM upto a point was not looking pretty, as usual the GFS was pumping out  dream  charts, and then the gfs flipped to long draw SW winds which backed the ECM for a while, the models were all over the place. 

Gradually the models got a handle on what was going on up in the atmosphere and we all know what happened then.

what im trying to say in a nut shell is the models will flip and flop around like a fish out of water for sometime to come until they can get a handle on the strat and everything that goes on around it.

 

Fromey

complete Novice

 

 

    

[Chesil View]

2 hours ago, SLEETY said:

Can't believe their isn't more excitement in the forum considering the METO have now joined the rest of us who have been forecasting a very cold end to the year,start of the new year.The last time I can remember then being this confident so far out was the cold blast in end of Feb this year and end of Nov2010

look how they both turned out!

Models won't pick.up in it yet as its not in their time frame...yet.Keep the faith!

 

 

Great post Sleety. We are in that limbo period at the moment where the pro,s at the Meto and the more learned members of this forum are as sure as they can be of a significant change to cold/very cold/snowy conditions sometime around new year but the nwp models are not close enough yet to have a firm handle on it.

Yet people still tie themselves in knots over an op run or two that doesn't, show wintry Nirvana

People need to realise that if the normally ultra cautious Meto are as bullish as this about something then they must be getting a very strong signal as per Nov 2010 or Feb 2018.

Let's face it we get enough posts on here saying that despite what ECM and GFS are showing. I won,t believe it until the Meto are saying it too. Well folks the Meto are saying it. So just enjoy Xmas white or not in the knowledge that the best forecast organisation in the world is as sure as they can be that winter is  on its way.

 

Edited December 15, 2018 by Broadmayne blizzard

[Bristawl Si]

32 minutes ago, blizzard81 said:

Iberian heights stronger than what was originally modelled. 

Yep! Been banging on about this for last couple of weeks. May be a spoiler for blighty, even if any SSW occurs.

As many on here say when a HP establishes itself it can be a git to shift. Those heights have been there or thereabouts for a couple of weeks now and are likely to stay in pos for next 2 weeks.

[bluearmy]

9 minutes ago, Broadmayne blizzard said:

Great post Sleety. We are in that limbo period at the moment where the pro,s at the Meto and the more learned members of this forum are as sure as they can be of a significant change to cold/very cold/snowy conditions sometime around new year but the nwp models are not close enough yet to have a firm handle on it.

Yet people still tie themselves in knots over an op run or two that doesn't, show wintry Nirvana

People need to realise that if the normally ultra cautious Meto are as bullish as this about something then they must be getting a very strong signal as per Nov 2010 or Feb 2018.

Let's face it we get enough posts on here saying that despite what ECM and GFS are showing. I won,t believe it until the Meto are saying it too. Well folks the Meto are saying it. So just enjoy Xmas white or not in the knowledge that the best forecast organisation in the world is as sure as they can be that winter is  on its way.

 

I expect if we had access to the modelling that Exeter do then we too would be excited ........ the stuff we can see isn’t showing us the route to deep cold just yet ..... it feasible that the met office modelling is also headed in the same direction as the final blocks are put into their expected places for the scenario that the cold glosea and ec 46 clusters show ...... but we can’t see that route so we remain in a state of ‘meh’.  Will be notable if/when the 30 dayer drops its suggestion that the onset could be brought forward to the turn of the year 

[bluearmy]

3 minutes ago, Bristle boy said:

Yep! Been banging on about this for last couple of weeks. May be a spoiler for blighty, even if any SSW occurs.

As many on here say when a HP establishes itself it can be a git to shift. Those heights have been there or thereabouts for a couple of weeks now and are likely to stay in pos for next 2 weeks.

In the short term they could well be a pain but I see them either retrogressing as a mid Atlantic ridge is finally pumped up or extending northeast and eventually being undercut 

[Bristawl Si]

Just now, bluearmy said:

In the short term they could well be a pain but I see them either retrogressing as a mid Atlantic ridge is finally pumped up or extending northeast and eventually being undercut 

Possibily. But read one of Stuart's (GP) posts in strat thread from the other day. He seems to hint/caveat the Iberian heights could be a continued 'player' post any SSW.

[Duane S.]

Big differences for just a week’s time though.

00z...

 

06z...

[Weathizard]

There’s still too much risidual is energy around Greenland, day 10 a coupe of days ago was showing a real waning of the energy in that area but now it’s still reigning supreme. This is a model discussion thread, so anyone being ‘negative’ is just reacting to what the models are showing right now, METO outlooks are all well and good but the models aren’t showing that at present and this is model output discussion.

 

Patience required of course, as usual with these isles, the MET are very rarely as bullish as they have been BUT this is no guarantee, so on model output alone you can understand the doom and gloom.

[Guest]

7 minutes ago, s4lancia said:

Big differences for just a week’s time though.

00z...

 

06z...

With such big differences run to run its clear something is happening that the models are not finding it easy to resolve. think we will see more wild swings in output over the coming few days maybe longer whiles the models struggle to get to grips with this.

[Seasonality]

10 minutes ago, s4lancia said:

Big differences for just a week’s time though.

00z...

 

06z...

Yes, as a few have been pointing out the swings are notable run to run. 

[claret047]

Good Morning everyone.

As a relative novice I was surprised at the reaction to the 00Z run with all the negativity it had caused.

I believe it was John Holmes that has stated in the past that it is all about trends. We will know soon enough if our excitement was premature, but I suggest that we wait at least another two (possibly three) runs before we throw in the towel. 

In any event there will be plenty of excitement later today for our friends in the north of the UK and hope you enjoy it.

Kind Regards

Dave

[weathergeek]

30 minutes ago, fromey said:

 Gradually the models got a handle on what was going on up in the atmosphere and we all know what happened then.

what im trying to say in a nut shell is the models will flip and flop around like a fish out of water for sometime to come until they can get a handle on the strat and everything that goes on around it.

 

Fromey

complete Novice

 

 

    

I have to say, I've been an avid reader on here since 2011 and despite having learnt a lot, I still class myself as a novice too. I still may not be an expert chart de-coder BUT I have been through enough cold spells/beasts/potential beasts/fails etc and have read enough of the corresponding posts to understand how these things work and play out..... it shocks me that although I class most members in here more knowledgeable than me, I see the same comments rolled out time after time. We are undoubtedly in a very obvious "flip flop" situation at the moment due to the models not being able to grasp the unique situation we're in. Although I can't guarantee they will all end up showing a Snoasis, we just need to keep looking at the broader theme and watching all the other indicators and not just the run from run ☺

[Methuselah]

16 minutes ago, More Snow said:

With such big differences run to run its clear something is happening that the models are not finding it easy to resolve. think we will see more wild swings in output over the coming few days maybe longer whiles the models struggle to get to grips with this.

Algorithmic (not meteorological) chaos, perhaps? One can see why Meteogroup and Met Office are suggesting something in the region of a 60% chance of January cold...?

Edit: I'll be glad when the FV3 finally comes online; I'm still stuck on yesterday's 06Z!

Edited December 15, 2018 by Ed Stone

[Man With Beard]

Clusters this morning: if there's going to be a cold snap during the Christmas period, the ECM ensembles suggest it will be earlier in the period rather than later (if at all, of course). By the 23rd, we see positive height anomalies in the Atlantic to our west, and clusters 1/3 look promising for getting a northerly flow down into the Atlantic shortly after (level of amplitude to be decided). 

The key for the UK is getting the trough to push east, as the FV3 is currently doing, but the ECM op is reluctant to do. 

However, after Christmas day, the clusters are not overly interested in cold, as ridging tends to move from favourable spots (control cluster perhaps excepted) 

 

[IDO]

7 minutes ago, Seasonality said:

Yes, as a few have been pointing out the swings are notable run to run. 

Yes, changes run to run, but each run maintaining the same theme, just timing and spatial variations. The 06z compared to the 0z on GFS differ but are both pretty zonal from start to finish. If we were getting some blocked charts or some other potential run to run then I would agree on your implied comment, but at the moment (usual caveats) that is far from the case.

D10 ECM mean: 

All can change and no doubt will, but when is the pertinent question?

[KyleHenry]

March 2018, the ECM failed to factor the effects of SSW and was late to portray the correct displacement effects down to the tropospheric level. Whereas the GFS had the right overall idea but failed with the correct Synoptics at the Trop level. When the ECM corrected its input (4 days later than GFS) it displayed the correct outcome. 

 

At 240z but models are following the same March 2018 resolution in reading SSW effects.

 

 

SSW equals PV displacement equals Pacific WAA equals -AO. That we know is certain. 

Strength of SSW (unknown at present). Is it enough to overcome dampening effect of upper WQBO remain unknown. 

[Mike Poole]

All but one GEFS member showing a technical SSW by the end of the run, so now up to 20/21:

Pretty sure there's only one there that doesn't dip below the line!

[northwestsnow]

2 minutes ago, Mike Poole said:

All but one GEFS member showing a technical SSW by the end of the run, so now up to 20/21:

Pretty sure there's only one there that doesn't dip below the line!

Best news of the morning imho..

Thanks Mike

[blizzard81]

10 minutes ago, Mike Poole said:

All but one GEFS member showing a technical SSW by the end of the run, so now up to 20/21:

Pretty sure there's only one there that doesn't dip below the line!

That's great news. Let's hope for much more pleasing on the eyes 12z runs later. 

[blizzard81]

1 hour ago, Leon1 said:

This happened with this cold snap though didn't it and at the last minute it suddenly appeared back on the charts. 

This isn't aimed at you @blizzard81 BTW but everyone on here needs to realise that it's all still to play for. Let's pray for the 6z runs.  

I certainly haven't given up lol. Just commenting on the latest runs. Onwards and upwards! 

[IDO]

6 minutes ago, Mike Poole said:

All but one GEFS member showing a technical SSW by the end of the run, so now up to 20/21:

Pretty sure there's only one there that doesn't dip below the line!

 

So from my untrained understanding, zonal winds will reverse between Dec 24 & Dec 29 (as per GEFS variations) and then maybe up to 14 days for a trop response? So by mid-next-week, we should see something showing in the GEFS that we could attribute to the SSW? We are heading into prime Wintertime, so for once an SSW can deliver some wintriness, rather than be wasted on a cool Spring!