Model output discussion - cold spell approaching?

[bluearmy]

day 8 and broadly the main ops on the same page noaa and ec 

differences with the greeny wedge/ridge and the arctic ridge 

maybe the slower route more likely now and also the less cold one (in the short term anyway). The initial northerly pre 20th was never that cold and now we go beyond the  20th it could be that by the time we can get the northerly in, the cold uppers won’t be there as was originally modelled .....

hey ho ........

[Mucka]

5 minutes ago, bluearmy said:

By day 7 it’s the gfs op!

incidentally, assuming ssw related but the lows struggling to  get past the meridian out to day 7 to our north which means we struggle to clear the upper trough to our east and advent the cold across nw Europe. Watch the feature at day 6 and 7 n of Scotland ....it moves sw. 

 

It is a consequence of the low bursting into the channel and phasing. sling-shot effect as far as I can tell i am understanding what you mean.

That low stays closed or held back SW and  the trough should do its thing. even it phases a bit later and further S it would not blow up like that and cut off the cold feed so I think we are seeing the worse case scenarios here with that. (At least I hope we are!)

[IDO]

I mentioned yesterday that the Greenland heights, more like a wedge, have been modelled on the gefs for a brief 4-5 day driver, so nothing has really changed, it gets warmed out. If this is a strat>trop imprint then I am surprised this happens, unless the strat is waning in that region.

The same as yesterday, and the concern for many of us, no cold uppers, so no cold pooling, therefore any ebb and flow from the Iberian heights will effectively look like a sine wave pattern for the south:

It does look like the response will not favour us in January. I was already resigned to the fact the pattern would never bring a BFTH via a Siberian or Russian high. Now it looks like the delay from the UK cut-off trough (d6-10) stops the cold reaching us as we see the Greenland wedge degrade in the same period. This setup has limited option and even great looking charts like the ecm at d9 has the UK trough low totally cut-off from the severe cold in the NE:

[bluearmy]

Day 9 with an upper ridge over the Baltic where yesterday’s 12z op had a chunk of vortex .............

I guess that’s why it fi !

[Guest]

I'm no Columbo but going by the MET update for 17th- 26th Jan, we should be looking to the NE, Cold conditions from Scandinavia! Make you wonder if we're about to see a shift!

 

[KTtom]

If you think we've had a reversal of fortunes regarding cold, look at Scandinavia, went to bed last night with the prospect of -25uppers next week and woke up to the prospect of +5 uppers!

 

Edited January 13, 2021 by KTtom

[bluearmy]

Does anyone think the day 10 NH chart has potential .................

 

 

I’ll get my coat .....

[swfc]

Ec gives more of a go at ridging towards Greenland ete but it's slightly underwhelming. To the east the PV and real cold 850s are moved away in regard to yesterday's runs pulling in low 850s. Very fluid atm if frustrating but all subject to ebbing and flowing. 

[bluearmy]

5 minutes ago, Snowmut said:

I'm no Columbo but going by the MET update for 17th- 26th Jan, we should be looking to the NE, Cold conditions from Scandinavia! Make you wonder if we're about to see a shift!

 

 I guess we’ll find out later today when the 12z’s, eps and clusters appear and are analysed if that’s still valid ......

[Mucka]

13 minutes ago, prolongedSnowLover said:

Looks like the signal for a severe cold spell is diminishing by the day with fewer members going below -10c and more milder options appearing.

Quite a climb down. 

If people were upset yesterday with only -8 850's showing they are going to be crying in their cornflakes this morning.

It is maddening though how often spoilers pop up just when we get to touching distance of calling a cold spell.

Let's hope this is one the rare times it flips back.

[Mucka]

3 minutes ago, bluearmy said:

Does anyone think the day 10 NH chart has potential .................

 

 

I’ll get my coat .....

 

That's funny but the sad truth is it does! 

Southerly tracking lows disrupting into cold air with forcing from the N, just need the cold air

[Paul]

Feels like this may be pertinent this morning.. Please use the chat thread for pure moans so this thread can be kept model related.

One or two posts have recently been moved in there.

[JoeShmoe]

I suggest folk enjoy what is right in front of them which is a possible snow event today / tomorrow in many parts of the U.K. 

on the model front this is another affirmation (to me at least) that until the UKMO is on board at <120 hours all these day 10 charts age as well as a pint of milk in the Sahara desert

[NewEra21]

23 minutes ago, prolongedSnowLover said:

Looks like the signal for a severe cold spell is diminishing by the day with fewer members going below -10c and more milder options appearing.

Whilst true, it was only yesterday we had the strongest cold clustering yet. I still feel there are so many ups and down to come, whether they're right or wrong.

[carinthian]

9 hours ago, Midlands Ice Age said:

This post has intrigued me.  Carathian,,,

 It (probably you) suggests that the low developing over the central UK is going to change the pattern?

Could it be that it is expected to deepen and possibly move SE and at the same time strengthen the Scandinavian high.!!

That is my hopeful guess at any rate  from your heavily disguised statement. It would obviously render most of the current modelling useless. 

The fact that you have posted the UK Fax chart which shows the low forming and the lobe of the Scandy high suddenly appearing looks a little different to the last weeks models. 

?????

MIA

 

Sorry about the delay in reply, we go to bed early in these parts ! Yes the models still show a long winding road to get real cold in to your parts. With regards to your post, the block of cold air is still very close out to 96h as shown on the latest UKMO chart below. So you can still hope for an outside chance of some sort of undercut into the cold mass , especially as trough formation over the British Isles is put back westward with each run. However, no support for this from the models in the medium term for this to evolve. However,  resilience  of the high out to the east  has been generally under played too readily in the longer term models.Maybe with time you will eventually get some old fashioned cold moving in from the East/ Northeast without any complication !

C

[bluearmy]

Just waiting for saturdays fax to be issued but fri night issue has already lost the warm front (although a warm sector still showing )  compared to previous run and it may disrupt and slide as it moves across into the ridge 

Edited January 13, 2021 by bluearmy

[northwestsnow]

EC looks very wet and very windy to me ?

Poor Marco must be scratching his head this morning!

 

 

Edited January 13, 2021 by northwestsnow

[Penrith Snow]

The problem really is that the colds arrival was always in FI which at the moment is 144.

I think we have been drawn in because the Stella FI charts coincided with expected effects of the SSW, had their been no SSW then we would have been more suspicious.

still time for things to flip back yet and at least this wobble had occurred at the outer reaches of the reliable timeframe rather than FI.

For mr the worry for the last few days has been the rise in Iberian heights, you really don’t want that winter killer because it can become so stubborn.

 

let’s wait for the evening runs before throwing in the towel but I have a bottle of 14% Red on the table and this is going to get opening this afternoon if the current trend is maintained.

Keep the faith a bit longer guys

andy

[Djdazzle]

I’d wait for the 12z runs before calling time on this, but there always looked to be too many potential banana skins to get decent cold into the UK in the next 7-10 days. The Iberian heights was always a big issue here. It’s fine to look at stellar FI charts and drool over them, but if you allow yourself to be drawn into thinking it’ll be a reality, you will be disappointed.

Yes, it’s the 0z runs which always seem to be poor, but the trend isn’t good. Let’s see what the 12z’s come out with.

[Paul]

1 minute ago, bluearmy said:

Just waiting for saturdays fax to be issued but fri night issue has already lost the warm front compared to previous run and it may disrupt and slide as it moves across into the ridge 

3z ukv is quite snowy on Saturday, so suspect the fax may follow along similar lines.

[Severe Siberian icy blast]

Just now, Paul said:

3z ukv is quite snowy on Saturday, so suspect the fax may follow along similar lines.

Well this is every interesting

[mountain shadow]

All the means, majority of ens had been pointing to the cold arriving at day 6, now we are back to day 10 again.

Very strange. 

[bluearmy]

1 minute ago, Paul said:

3z ukv is quite snowy on Saturday, so suspect the fax may follow along similar lines.

Yes note T72/T84 as the warm sector heads south with the occlusion 

(Can’t post the two charts)

[Djdazzle]

2 minutes ago, mountain shadow said:

All the means, majority of ens had been pointing to the cold arriving at day 6, now we are back to day 10 again.

Very strange. 

I wouldn’t say it is strange - with all of the volatility, even whole ensembles suites can flip.

[northwestsnow]

Well, of course at the timeframes involved there could be a shift back the other way.

I'm desperately trying to stay optimistic but its clear as day the trend is not good this morning.

Is it fair to say cold hunting in this country is a bit masochistic?