Jump to content
Sign in to follow this  
Paul

Hunt For Cold: Model Discussion - Heading Into Christmas

Paul

If you're hunting for cold potential in the model output, this thread is for you. But if you'd like to look more widely at the models, please head over to the general model discussion thread.

This is a model related thread, so a general, frequent theme of the model output is a given, but it will not be strictly enforced:

  • Some topic drift, humorous responses etc are fine
  • Posts likely to lead the thread off on an entirely off topic tangent are not ok. For example (but not solely limited to): Posts entirely or mainly about Met Office, BBC or media forecasts with little or no model context, and posts solely asking for a weather forecast in a specific location.
  • Posts which start with something like 'I know this is off topic but ...' are not ok.
  • Posts which break the forum guidelines are not ok (eg trolling, troll-hunting, weather guilt tripping, overly defensive/aggressive, abusive, disrespectful to others)

Message added by Paul

Recommended Posts

41 minutes ago, feb1991blizzard said:

I would like to see the 1mb chart, i dont think the 10mb split is getting any wider from the last run.

A little wider and more notably, it seems to immediately downwell to 30 and 50hpa at the end of the run 

Share this post


Link to post
Share on other sites
3 minutes ago, Steve Murr said:

The split getting wider is a VERY positive signal for UK cold !

Yup, and a small improvement on the EC mean tonight with high pressure slightly further north- start of a trend?

 

Share this post


Link to post
Share on other sites
3 minutes ago, Steve Murr said:

The split getting wider is a VERY positive signal for UK cold !

Yes, ideally you want one lobe over canada, the other one right over to Russia, so as it's imprints on the trop, you end up with one of those big long scandinavian highs so you get a nice big long fetch  of air all the way from Eastern Russia and Siberia.

Share this post


Link to post
Share on other sites

@Man With Beard 2009 was 9 years ago ..... we should hope that modelling has moved on enough that we don’t get such a turn around ...........

Share this post


Link to post
Share on other sites
5 minutes ago, bluearmy said:

@Man With Beard 2009 was 9 years ago ..... we should hope that modelling has moved on enough that we don’t get such a turn around ...........

Right get in the bin, they'll be no making me feel old on this forum!

Edited by Daniel Smith

Share this post


Link to post
Share on other sites
4 minutes ago, bluearmy said:

@Man With Beard 2009 was 9 years ago ..... we should hope that modelling has moved on enough that we don’t get such a turn around ...........

But it also did it in March this year?

Share this post


Link to post
Share on other sites
2 minutes ago, bluearmy said:

@Man With Beard 2009 was 9 years ago ..... we should hope that modelling has moved on enough that we don’t get such a turn around ...........

What's getting me is that, in the ECM ensembles, I can't see any sign of a response in the TPV to events in the SSW. Or at least what I am expecting - which is a large areas of low pressure disintegrating somewhere in northern latitudes. Or is supposed to be a slow downwelling? You know more than me about this BA - sorry if this is covered further back in the thread but I don't have time to read everything on here in winter 🙂 

Share this post


Link to post
Share on other sites
35 minutes ago, Steve Murr said:

The split getting wider is a VERY positive signal for UK cold !

Hi Steve, could you tell me as I'm clueless on all this but even if it does split, could it just simply rejoin a few days or weeks later? Thanks.

Share this post


Link to post
Share on other sites
3 minutes ago, Man With Beard said:

What's getting me is that, in the ECM ensembles, I can't see any sign of a response in the TPV to events in the SSW. Or at least what I am expecting - which is a large areas of low pressure disintegrating somewhere in northern latitudes. Or is supposed to be a slow downwelling? You know more than me about this BA - sorry if this is covered further back in the thread but I don't have time to read everything on here in winter 🙂 

I don’t have the time to look through 50 runs but I knew you would ! It’s not easy to see a QTR unless the model is moving frame to frame .....  The reversal looks to be around the 29th so a QTR could be showing by 2nd/3 rd jan so that’s right at the end of the eps. The gefs look a couple days quicker on the reversal so maybe that’s why we see one member going QTR

i think a couple more days to wait 

5 minutes ago, That ECM said:

But it also did it in March this year?

I wondered about this .... feb 11th was the SSW. Gfs ops were showing the response late in their runs by 6th feb ..... as it turned out they were a little progressive re the response. The point being that the gfs ops and ec op were showing a response before the warming took place 

Share this post


Link to post
Share on other sites
14 minutes ago, Allseasons-si said:

Just posted this in the strat thread and thought that i would post it here too, it rivals the warming earlier this year,a Dec rocerd?

 

And this is just the latest thing that leads me to believe that we are on the cusp of something special, one of two things we may not have seen before.  The other being the models inability to get a grasp of what the strat warming looks like at a timescale when they should!  It may be something new...

For the north hemisphere, this event looks highly significant, for the UK that has to be tempered by our location, 'if it can go wrong it will go wrong'  

Having said that where we stand today, I think it's more 'if it can go right, it will go right'.

What we need to see now, is a firm up of the ECM version of the SSW, One warming leaving the residual vortex well split.  This scenario looking more likely by the day to me.  Interesting to watch how (if) it unfolds...

Edited by Mike Poole

Share this post


Link to post
Share on other sites
11 minutes ago, bluearmy said:

I don’t have the time to look through 50 runs but I knew you would ! It’s not easy to see a QTR unless the model is moving frame to frame .....  The reversal looks to be around the 29th so a QTR could be showing by 2nd/3 rd jan so that’s right at the end of the eps. The gefs look a couple days quicker on the reversal so maybe that’s why we see one member going QTR

i think a couple more days to wait 

I wondered about this .... feb 11th was the SSW. Gfs ops were showing the response late in their runs by 6th feb ..... as it turned out they were a little progressive re the response. The point being that the gfs ops and ec op were showing a response before the warming took place 

Thing is during the last two SSWs in 2013 and 2018 we were very lucky to see two examples of perfect splits - a displacement followed immediately by a clear split. We still don't know what's happening with the potential split, whether it will be a partial one, a full one or even if it will happen at all. I think it's clear the models are struggling with forecasting what happens after the displacement as the fate of the vortex is still unknown after that.

Edited by Snowy L

Share this post


Link to post
Share on other sites

Ec46 weeks three and four due imminently. I would expect the high anomoly to be present across n uk week 3 and possibly edging nw for week 4. The previous run was v progressive moving that block nw week 4 and i expect this run will be a little slower 

Edited by bluearmy

Share this post


Link to post
Share on other sites
10 minutes ago, bluearmy said:

Ec46 weeks three and four due imminently. I would expect the high anomoly to be present across n uk week 3 and possibly edging nw for week 4. The previous run was v progressive moving that block nw week 4 and i expect this run will be a little slower 

No QTR to the proposed SSW?

Share this post


Link to post
Share on other sites
2 minutes ago, Steve Murr said:

Overall the likelyhood is with a split is one lobe will fade away as the main lobe will begin to restrengthen - however if you get a big split through all the layers then essentially thats the engine broken with only mild recovery-

This recover could well be tempered by the ongoing upward assault of wave 1 activity where the strat remains sub say 25M/S for the rest of the winter-

In laymens terms a December warming + Split @10HPA of this magnitude with record breaking heat flux as always precluded 'peak' negativity in the AO, the period of 05/01/19 to 19/01/19 will most likely yeild the most negative AO of the winter - possibly record challenging-

For the Uk the QTR ( Quick troposheric response ) seems at this stage to favour the UK-

What you will see from the QTR is a 1 or 2 wave pattern diving into the pole - This is where because of where I highlighted the split

9B7FAE4D-3C60-44DD-A6CA-DC611BDC9B90.thumb.jpeg.384229a1574f69d9b724424c11ceec3b.jpeg

Alligns nicely to of 2 High pressure that may link into the 2 wave Pattern

The very *Early* prognosis is -EPO & Atlantic ridge to Scandi link up- in that case its a big thumbs up to a QTR-

However there are many other manifestations & pairings that do occur - more common being the cross polar flow coming from a siberian link up with the PNA ridge- Very cold for the Eastern us- no great for us-

C0F1898D-E938-4017-B506-DC3766746E6D.thumb.jpeg.08b16851291a7d3445b7a287e6f70e9d.jpeg

The map above highlights all the entry points-

The QTR ( end of Dec ) if it occurs favours -EPO / Atlantic ridge combo....

 

Thanks for taking the time to answer my question Steve.. . Hopefully it will all turn out cold and snowy for us and for once not at the end of the season but sometime in the early part of Jan. 🖒❄

Share this post


Link to post
Share on other sites
4 minutes ago, karlos1983 said:

@feb1991blizzard I must be doing something wrong 🤷‍♂️ can't find the link for the 46 anywhere in there

http://brunnur.vedur.is/kort/ec-ens/2018/

Or i is just fick :pardon:

Select the month (12) - select the day (20th) then just leave it there and keep refreshing until you see the am time (10:35) - become 22xx  then when it does, click on the 00z, scroll down to the first thing you see that has a 22xx time stamp on it.

http://brunnur.vedur.is/kort/ec-ens/2018/12/20/

Edited by feb1991blizzard

Share this post


Link to post
Share on other sites
3 minutes ago, bluearmy said:

Icelandic site not updated yet!

Yep. Almost predictable now. Always happens (not just ec46) when anticipation is at it's greatest. 

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...