Model output discussion - 7th January onwards

[winterof79]

So it's like 're assuring kids that there are no monsters under the bed.....

Draining of the sister still forecast and the split complete on ECM 

GFS good run draining away and going in right direction....come on guys if you can't read the charts don't comentate incorrectly please 

 

[markw2680]

39 minutes ago, shaky said:

Dont know what to make of the ukmo!!dunno if anyone gets any snow out of that slider at all!!and gfs is still stubborn!!all the yummy charts back into fi again and everything flat!!give us a break!!

That’s because people take every run as gospel, the first slider was never really going to deliver anyway from what I can recall just a transition into colder weather.

many really good charts show up in fi and remain in fi, there really is no point looking further than say 144 imo other than maybe looking for a trend

[bluearmy]

57 minutes ago, shaky said:

Is this a good thing or bad thing for us

Ukmo would be better - less ridge means the pattern is further west

ukmo looks isolated though

extended look a bit flatter than before in the 12/13 day period ..... hopefully this isn’t the beginning of the relaxation in Euro troughing depth I was worrying about - if it is, then then any cold becomes less sustained for the southern half of the country - of course that says somewhere will be very dumped on !!

Edited January 14, 2019 by bluearmy

[East801]

A frustrating start to the day across NWP, the Azores high is proving to be a real pain. Everything too far east today, let’s hope for a correction west as the day progresses and some early hints of HLB.

A

[Met4Cast]

UKMO/ECM/GEM all slide the low. Hell, even the FAX charts produced by the Met Office are sliding the low. 

The GFS is a step closer to sliding on the 00z but still doesn’t manage it, bizzare! Anybody still think the GFS is right?

[karlos1983]

That Azores high needs to do one! Not helping us in anyway at all!the complete opposite! 

EC and UKMO still slide, but the ops not quite as good as yesterday for immediate cold prospects.

EC ens for southern England 

 

[bluearmy]

Just now, Daniel Smith said:

UKMO/ECM/GEM all slide the low. Hell, even the FAX charts produced by the Met Office are sliding the low. 

The GFS is a step closer to sliding on the 00z but still doesn’t manage it, bizzare! Anybody still think the GFS is right?

It doesn’t really matter though Daniel ... it’s unlikely to bring any decent wintryness 

Its now about what comes behind it - 

[Met4Cast]

2 minutes ago, bluearmy said:

It doesn’t really matter though Daniel ... it’s unlikely to bring any decent wintryness 

Its now about what comes behind it - 

Perhaps, but it is of interest given the timeframes and the differences between the models re: the low even at 96hrs, whether it brings wintriness or not

[mountain shadow]

4 minutes ago, Daniel Smith said:

UKMO/ECM/GEM all slide the low. Hell, even the FAX charts produced by the Met Office are sliding the low. 

 

For the vast majority it delivers nothing anyway so we're back to chasing the snow in plus ten days range.

[JeffC]

Isn't some of this just the Monday morning blues? 

Seems to me, as I've said before the overnight run comes back with a more disappointing output which sets people's optimism back, but as the day progresses the outputs improve and bring improved prospects for cold. 

I'm not as skilled as many or as long in the tooth in model watching as a lot of folk on here, but I've never seen such a consistent situation with the 00z on pretty much all model suites giving less encouraging developments. Is there any explanation? 

[mulzy]

14 minutes ago, bluearmy said:

Ukmo would be better - less ridge means the pattern is further west

ukmo looks isolated though

extended look a bit flatter than before in the 12/13 day period ..... hopefully this isn’t the beginning of the relaxation in Euro troughing depth I was worrying about - if it is, then then any cold becomes less sustained for the southern half of the country 

Yes, disappointing ext EPS (not terrible but trending less colder).  The core of the lower heights heading too far west meaning that the mean trough is positioned over Ireland instead of over the UK.  That allied with slightly lower heights than previously advertised in the Greenland/Iceland locale makes this set not as good as previous suites.

Edited January 14, 2019 by mulzy

[Guest Delete Me]

I'm sure 12z / 18z will restore our faith in modelling and repair the damage done by the runs this morning.

 

[Nick F]

Still plenty of model uncertainty over the direction of the low moving in off the Atlantic this weekend and potentially disrupting against cold high pressure that develops Friday. Below is a model comparison for Saturday.

However, there now seems to be consistency with the upper pattern next week, after big disagreement on timing of amplification prior, with EC and GFS now agreeing a ridge amplifying north over the Atlantic while forcing a deep trough  SE downstream across NW Europe, 

.... this may give a brief spell of milder, wet and windy weather before colder polar sweeps in from the NW. And, although the T850s don’t look great as is par of the course in a NW flow,  because of the rather low heights being progged, freezing level will be low, so could be quite snowy for the north under the trough.

Because of the amplification upstream, the trough digging SE into Europe will hopefully disrupt too, allowing height rises to our N or maybe even NE to open up, then we could see deeper cold advection opportunities late Jan into early Feb.

 

[mulzy]

8 minutes ago, JeffC said:

Isn't some of this just the Monday morning blues? 

Seems to me, as I've said before the overnight run comes back with a more disappointing output which sets people's optimism back, but as the day progresses the outputs improve and bring improved prospects for cold. 

I'm not as skilled as many or as long in the tooth in model watching as a lot of folk on here, but I've never seen such a consistent situation with the 00z on pretty much all model suites giving less encouraging developments. Is there any explanation? 

Yes, as we sleep we dream of a winter Nirvana and feel deflated when the outputs don't show such a scenario!  Expectation management is the cause!

Edited January 14, 2019 by mulzy

[Easton Luna Boys]

13 minutes ago, mountain shadow said:

For the vast majority it delivers nothing anyway so we're back to chasing the snow in plus ten days range.

Yes, everything looks to have shunted east again with the AZH looking ominous. FI remains firmly in FI. The wait continues. 

[SLEETY]

19 minutes ago, bluearmy said:

It doesn’t really matter though Daniel ... it’s unlikely to bring any decent wintryness 

Its now about what comes behind it - 

Seemed to matter last night to many posters that the gfs was going to be correct yet 12 hours on its still on its own regarding that low.

[Johnp]

27 minutes ago, SLEETY said:

Seemed to matter last night to many posters that the gfs was going to be correct yet 12 hours on its still on its own regarding that low.

Delete

Edited January 14, 2019 by Johnp

[feb1991blizzard]

12 minutes ago, mulzy said:

Yes, disappointing ext EPS (not terrible but trending less colder).  The core of the lower heights heading too far west meaning that the mean trough is positioned over Ireland instead of over the UK.  That allied with slightly lower heights than previously advertised in the Greenland/Iceland locale makes this set not as good as previous suites.

That was my fear wrt slight upticking in the graph at the end, thats how breakdowns always start and from experience, they rarely trend back, lets just hope that any uptick is just brief.

[Duane S.]

Regards the initial slider, IMO, unlikely too be much of a snow event for the masses (possibly a bit of backedge). Worth reminding some that it was never really touted to be at that stage, if it does ending up producing a few cm away from the normal elevated areas, to be treated as a bonus.

Quick question though...

Why, when we all (surely by now) know that the models are going to struggle with the SSW and its subsequent effects on the troposphere, are we expecting, of all things, consistency!?

I come on this forum and read pages of people apparently in absolute shock and horror that the latest suite is wildly different to those of previously. Be it 'better', or 'worse'

No downgrade trend. Same entropy. Same potential. Just enjoying this evolve

[nick sussex]

Very bizarre goings on.

The stand-off starts as early as day 3 between the GFS and the Euros . This hardly ever happens and it’s not as if the area in question suffers from a lack of observational data as might be the case in parts of the Pacific.

Putting this early drama aside there is better agreeement later on.

During that time the interest is whether we see a full blown low head se or whether more trough disruption occurs. I think the models have moved towards the former which is less good for snow prospects during that period as the cold will get mixed out ahead and it won’t be till low pressure heads sufficiently se before the cold can move back sw over the top .

A caveat here is that the behaviour of that low is effected by developments towards the eastern USA with a low which moves east ne from the southern states . The track of that could still change this far out .

The UKMO at day 6 has the more amplified solution there .

Earlier the UKMO looks like there’s a chance of some snow on the eastern flank of the shortwave which runs se at day 5 and 6 . 

So a lot going on , lots of early disagreements and still more chopping and changing likely .

[IDO]

Pure dynamics of the NH pattern pushes us towards that Euro trough around the D10-D12 range. It is how we get there that has always been the issue if we can squeeze some snow out of the pattern change, but even now the complex nature of all the interactions means low confidence. The GEFS have been chaotic and I assume there is entropy. With chaos we expect the models to be inconsistent and to shame GFS for being that is harsh. 

Without the wedges from the last two ECM op runs we see no disruption to the chunk of PV spewed from the vortex. This washes out the uppers so the chances of snow lessen at the D10 stage, especially for some areas in that flow, though academic at that range. The D9/10 charts should probably have a Health Warning as I suspect the ensembles reflect multiple routes.

Post the Euro-Trough that I am now interested in. The Canadian vortex remains a driver at D16 on the GEFS and mean:

It is less confined, so the interaction of the Atlantic Ridge -v- PV should move towards a greater chance of sustainable HLB'ing.

[Chesil View]

3 minutes ago, s4lancia said:

Regards the initial slider, IMO, unlikely too be much of a snow event for the masses (possibly a bit of backedge). Worth reminding some that it was never really touted to be at that stage, if it does ending up producing a few cm away from the normal elevated areas, to be treated as a bonus.

Quick question though...

Why, when we all (surely by now) know that the models are going to struggle with the SSW and its subsequent effects on the troposphere, are we expecting, of all things, consistency!?

I come on this forum and read pages of people apparently in absolute shock and horror that the latest suite is wildly different to those of previously. Be it 'better', or 'worse'

No downgrade trend. Same entropy. Same potential. Just enjoying this evolve

Top post S4L.  Just let the cold unfold.

[Catacol]

3 hours ago, CreweCold said:

And there's your building Scandi HP...

18 day downwell from 12th Jan...not a bad fit...clockwork.

ALL roads will lead to Scandi side blocking towards the end of the month, regardless of what transpires for us inbetween.

A bit west of there for me - Strat downwell is not removing all of the Scandy/Euro trough signal, and the term "Griceland" seems to be apt here. 

More important is the overall signal for a deep Euro trough. Where the 2 lobes go from here looks to suggest currently a transfer of the HP signal towards Scandy over time if we assume an exact vertical propagation of impact (which isnt always the case) and the upwards forcing from the trop may still have an influence in adjusting the vertical angle of what is left of the vortex energy to our easy - but it seems a fair call at present.

Also speed of downwell still slow - so I suspect a slightly longer lag.

So euro trough next week, to heights over Grice and then as we move forward through February agree that blocking to Scandy looks probable as things currently stand.

[Scandinavian High.]

All looking good for a colder spell maybe no significant snow this week it's next week where there is a chance of even colder weather I expect models to upgrade very soon so I really don't no why all down beat there was never really going to be  significant snow this week..

[BLAST FROM THE PAST]

45 minutes ago, Daniel Smith said:

UKMO/ECM/GEM all slide the low. Hell, even the FAX charts produced by the Met Office are sliding the low. 

The GFS is a step closer to sliding on the 00z but still doesn’t manage it, bizzare! Anybody still think the GFS is right?

As I said over recent days , GFS cannot be totally discounted.  I believed that any heights over/near Scandi would be shallow and temporary 20-24 period...possibly the slider situation we see but wouldn’t lead to HLB as there would then be a PV displacement event with deep trough moving NW/SE around 24-31. So blending them together sees the way forward imo.

Strange winter this one, and relying on troughing on NW/SE axis to bring our cold has proven not helpful thus far...and I still can’t see any lasting HLB in the nearterm.  Let’s see if the trough really drives into Europe as that would bring plenty of wintryness with NE and E winds

BFTP

Edited January 14, 2019 by BLAST FROM THE PAST