Model output discussion - is the beast awakening?

[joggs]

Just now, Singularity said:

The EPS 12z feature a marked increase in runs with the polar jet stream out of the USA too strong for the Scandinavian high to resist.

Where this has come from, we can only wonder - no clear changes in expected tropical or stratospheric forcing. So we'll have to wait and see if it's a fluctuation or not. Remember, the bitterly cold later stages to the 00z ECM were just one run ago!

There is indeed a huge spread by a week today. More so than with GEFS which also have a much better mean placement of the major features for bringing the very cold air west to the UK.

A new development today across the models in general has been an increased appetite to drop a trough down through western Asia or Scandinavia, bringing deep cold down from the north. This causes the deep continental cold to be sent packing eastward, to be replaced by the fresh import which then modifies to become Arctic continental.

The GFS 06z and GFS(P) 12z runs have shown us how this could happen without sacrificing a reasonably cold easterly interlude starting next Fri. This requires the Atlantic polar jet configuration to be highly meridional, not full of positively tilted trough action like the 12z ECM and GEM runs.

Yes re the jet stream over US. For the last few days it was calming down and certain signals due to put a brake on also then boom lol. You couldn't make it up. I know it's one set of runs but if it can go wrong for UK cold.............it will. Lol

[TSNWK]

2 minutes ago, CreweCold said:

Of course it's about deep cold. You're not going to get long lasting laying snow in Feb with a marginal set up. It's fine if you want falling snow and a couple of slushy deposits, but nothing more than that.

I'd like to get out there and walk in crunchy snow. Not once have I had the chance to do that this year due to any falls melting almost immediately.

Agree.. give me a week of what this mornings ECM and gfs were dishing out with sub —10s uppers @ ice days and I’ll take my chances on what if anything falls.. team! the clocks ticking we need showtime delivered from this particular model phase.

[Tim Bland]

Uncertainty is clear to see...

[sebastiaan1973]

Latest EC plume. Still a large cluster with easterly winds.

[PolarWarsaw]

15 minutes ago, winterof79 said:

You putting your house on the warnings for snow next week will be removed...... Presume you have more than one house. 

Your post just discounted an Easterly and any boundary snow event. 

I didn't discount it, but IMO - It won't happen. 

Going totally off topic though with that kind of discussion though. 

Do not be surprised to see warnings removed for early next week, away from perhaps Scotland and next weekend was always up for debate considering we have been here 100 times this winter and vast swathes of the country haven't seen more than a frost. 

Personally I'm quite content. We have had 7 days of accumulating snow, all with 1CM+ and then 16CM's last weekend, so my downbeat tone is more for those that wanted to see something covering the entire of the country. Winter has been great North of Birmingham. 

Edited January 29, 2021 by PolarWarsaw

[Uncertainty]

It’s bizarre how you can build up to a cold spell in the U.K. for days and have it snatched in one set of horrid runs. I mean,  We had a ‘That GFS’ type run, 6 god damn hours ago!!! 
 

So... Will this go down in the tyranny of failures (list too long and sad to mention) or will the 0z runs come to our rescue?

It has to be said, that the vast majority of the time in this situation, it’s the former

For now, EC has joined the 2nd cluster from this mornings output. Which has now swelled considerably.

 There were already small signs - iffy UKMO, a swerly at day 8 on the GEM, a less defined ridge to the North on the 12z GEFS and the subsequent loss of our solid 1035mb Scandi high from yesterday’s golden day. Not the 2 solid days of upgrades I said were required yesterday.

The difference in the ECM mean at day 10 from this time yesterday is stark

Yesterday

Today

 

The 850s make me  

Looking through the extended eps late on, around 20 have a giant block to the NE / N / NW but 10 have a horrific SWerly with a Euro high. The others are relatively non-descript, mostly anti-cyclonic. If we miss out on this opportunity it categorically is not ‘it ‘for this winter to say that would be total folly considering a) The 2nd strat weakening hasn’t even finished yet b) The mjo won’t be getting to phase 7 for 6 days at least c)it’s one set of runs and d) February hasn’t even started yet!

However, and I say this with a heavy heart... Based on my experience using a similar methodology to @feb1991blizzard, if tonight’s trends are not reversed on the 0zs: It (This particular shot at deep cold day 8-11) is finished

Why doesn’t this happen for mild weather

 

 

Edited January 29, 2021 by Uncertainy

[East_England_Stormchaser91]

11 minutes ago, CreweCold said:

Of course it's about deep cold. You're not going to get long lasting laying snow in Feb with a marginal set up. It's fine if you want falling snow and a couple of slushy deposits, but nothing more than that.

I'd like to get out there and walk in crunchy snow. Not once have I had the chance to do that this year due to any falls melting almost immediately.

I disagree Crewe. The lack of solar output in December is greatly offset by residual warmth from surrounding waters and usually a lack of cold on the continent. Early February is probably the best time to get the most out of Synoptics at the most marginal stage. Similarly with heat being best obtained in Late July/Early August despite lower solar output. 

[Froze were the Days]

35 minutes ago, MJB said:

And you have evidence of that ? 

Well not off my head but I'm not sure there have been that many occasions, widely known I believe that the Euros (ECM/UKMO) handle blocking, trough disruption better over this neck of the woods than the American GFS.

GFS was steadfast in the last cold debacle before mid-January with the Greenland High before dropping the idea at the last moment and we ended up with a filling low pressure in the south Norwegian sea.

All to play for and will have more of an idea once the UKMO moves a day ahead tomorrow, as the ECM is flapping around like a fish out of water presently.

[sheikhy]

2 minutes ago, Uncertainy said:

It’s bizarre how you can build up to a cold spell in the U.K. for days and have it snatched in one set of horrid runs. I mean,  We had a ‘That GFS’ type run, 6 god damn hours ago!!! 
 

So... Will this go down in the tyranny of failures (list too long and sad to mention) or will the 0z runs come to our rescue?

It has to be said, that the vast majority of the time in this situation, it’s the former

For now, EC has joined the 2nd cluster from this mornings output. Which has now swelled considerably.

 There were already small signs - iffy UKMO, a swerly at day 8 on the GEM, a less defined ridge to the North on the 12z GEFS and the subsequent loss of our solid 1035mb Scandi high from yesterday’s golden day. Not the 2 solid days of upgrades I said were required yesterday.

The difference in the ECM mean at day 10 from this time yesterday is stark

Yesterday

Today

 

The 850s make me  

Looking through the extended eps late on, around 20 have a giant block to the NE / N / NW but 10 have a horrific SWerly with a Euro high. The others are relatively non-descript, mostly anti-cyclonic. If we miss out on this opportunity it categorically is not ‘it ‘for this winter to say that would be total folly considering a) The 2nd strat weakening hasn’t even finished yet b) The mjo won’t be getting to phase 7 for 6 days at least c)it’s one set of runs and d) February hasn’t even started yet!

However, and I say this with a heavy heart... Based on my experience using a similar methodology to @feb1991blizzard, if tonight’s trends are not reversed on the 0zs: It (This particular shot at deep cold day 8-11) is finished

Why doesn’t this happen for mild weather

 

 

Precisely what i been trying to say!!it has to reverse on the 00z run!!

[Mike Poole]

If the ECM debacle is not for you, here’s tomorrow’s snow according to HARMONIE 12z:

Edited January 29, 2021 by Mike Poole

[damianslaw]

All ups and downs in the model thread today, must be major swings taking place from run to run and always a sign there is a pattern change on the way, but the models are struggling to get to grips with it. 

Too much volatility today for any comment I feel.

 

[SilverWolf]

4 minutes ago, PolarWarsaw said:

. Winter hs been great North of Birmingham. 

Actually it’s been pretty damn good 60 miles south of Birmingham - 4 days of lying snow, numerous frosts, crazy rain and flash flooding, hailstorms, thunder and lightning... most interesting winter for a while, and we’ve some weeks to go yet! 

[phil nw.]

Ok guys let's get back to the models.Some people are getting rather wound up and it's not acceptable.

Some posts have been removed so let's keep it friendly.Anything you think is out of order please report and not reply in here.

Thanks all.  

[PolarWarsaw]

6 minutes ago, SilverWolf said:

Actually it’s been pretty damn good 60 miles south of Birmingham - 4 days of lying snow, numerous frosts, crazy rain and flash flooding, hailstorms, thunder and lightning... most interesting winter for a while, and we’ve some weeks to go yet! 

Agreed, I've actually had a lot of fun this season. Best for years. 

But the small minority South of the M4 still haven't seen a flake. Would be nice to get them in on the action. 

If not only to keep them from moaning, whilst the North has all the fun. 

[Trom]

10 minutes ago, Mike Poole said:

If the ECM debacle is not for you, here’s tomorrow’s snow according to HARMONIE 12z:

Looks to be sleety away from Wales.  I think the orange hatching is sleet, is it not?

[Mike Poole]

Just now, Trom said:

Looks to be sleety away from Wales.  I think the orange hatching is sleet, is it not?

Graupel.  

[nick sussex]

I think perhaps it’s best to wait a few runs to see if this new signal is real and see how that evolves if that’s the case .

If the ECM moves a chunk of the PV eastwards we might well be looking more nw for any blocking initially .

You can still get a short easterly and then something from the north . The whole thing needn’t be a total write off .

 

Edited January 29, 2021 by nick sussex

[Scandinavian High.]

A lot as said ecm is not that good.  we had very good update from met office today Surely they are quite confident or can they get completely wrong . I don’t think it’s that straight forward with easterlys. In 2018 did models pick easterlys up then drop and bring them back or did models run with it with no dramas.

Edited January 29, 2021 by Scandinavian High.

[Djdazzle]

1 minute ago, Scandinavian High. said:

A lot as said ecm is not that good.  we had very good update from met office today Surely they are quite confident or can get completely wrong . I don’t think it’s that straight forward with easterlys. In 2018 did models pick easterlys up then drop and bring them back or did models run with it with no dramas.

2018 was pretty consistently modelled if I recall correctly. I don’t think the easterly was fully dropped at any point during the run up.

[Mike Poole]

3 minutes ago, Scandinavian High. said:

A lot as said ecm is not that good.  we had very good update from met office today Surely they are quite confident or can get completely wrong . I don’t think it’s that straight forward with easterlys. In 2018 did models pick easterlys up then drop and bring them back or did models run with it with no dramas.

That’s true, and we shouldn’t be panicking, I’ve said before that just random chance would have 6 major model runs in a 0z or 12z set give an adverse run about 1/64 of the time - so that’s about once a month.  And we’re not even there - GFS and GFS // were good.  So every chance it is a blip and the morning runs will be better.  Mind you the MO update will be before the 12z runs.  

[Trom]

23 minutes ago, Mike Poole said:

Graupel.  

Slightly different phenomenon same end result!

[Chesil View]

1 hour ago, sunnijim said:

One would hope that the Mogreps has a handle on this.

The volatility we are seeing in the free to view models is in sharp contrast to a confident long ranger from the M.O.

The update suggests a block to the North East from the 4th and all the way toward the end of February.

This sort of robust outlook in terms of widespread cold and snow hasn't been offered up so far this winter.

All the fantastic charts with 'potential'  we witnessed in December and January were never met with much of a response from Exeter.

 

As I said before none of the publicly available free to view  models are that great beyond 5 days which is presumably why mogreps and others models we don't get to see are so jealously guarded by the Meto.

[Radiating Dendrite]

6 minutes ago, Mike Poole said:

That’s true, and we shouldn’t be panicking, I’ve said before that just random chance would have 6 major model runs in a 0z or 12z set give an adverse run about 1/64 of the time - so that’s about once a month.  And we’re not even there - GFS and GFS // were good.  So every chance it is a blip and the morning runs will be better.  Mind you the MO update will be before the 12z runs.  

I would rather take the word of the meto than anyone on here or the free models. 

They were ridiculed prior to NY when they called a more UK based high....guess what happened! 

The update was punchy, so MOGREPS must be showing a consistently strong signal along with all the other bit they see that we do not. The ECM has not been great this winter in my opinion, usually playing catch up or overreacting.....a little like GFS of old. It could be right, but I expect a different looking 0z at which point another model will then probably jump ship!

Edited January 29, 2021 by Radiating Dendrite

[SqueakheartLW]

My summary of the 12z models

GFS 12z

Looks like another overall upgrade to the potential colder spell from later next week on GFS 12z

At 204 hours away we have this set of average ensemble charts

Overall still an average easterly at this stage and with a new low average 850hpa temperature of -8.5 at the peak of this colder spell, another -0.5 colder than it was at the peak on the 06z which takes the anomaly to -6.4 below the long term mean. Hope we can keep the downwards temperature trend going in future runs.

The coldest member at 204 hours away is Member 25

This followed by the mildest member at 204 hours away which is Member 12

GEM 12z

The GEM won't let me look at the mean charts on wetterzentrale but I can summarize based on the ensemble chart. At 162 hours away the GEM 12z reaches the peak of the colder spell with an ensemble average of -7.8 at 850hpa,which is -7.2 below the long term mean based on GEM. Not as cold as GFS in outright temperature but colder against the mean at the time. This is 2 models so far going for this colder spell.

The coldest GEM member at 162 hours away is Member 9

The mildest GEM member at 162 hours away is Member 14

GFS Extended

Just thought I would look at GFS Extended just to see if it is any different to the main GFS model. It too has this colder spell showing and it looks to peak at 228 hours away with an average 850hpa temperature of -6.6 which is -5.1 below the long term mean. Like with the other models there is some scatter and a good difference between the coldest and mildest options. As the operational run isn't a part of the extended set then despite it been the coldest of all at 228 hours away it doesn't count in my extended assessment so therefore we have to take 2nd coldest as the coldest extended member here

The coldest official extended run at 228 hours away is Member 5

The mildest extended run at 228 hours away is Member 6

Some doom and gloom mild charts from the extended GFS

Member 9     +372 hours

Control Run     +510 hours

Member 14     576 hours

Finally the worst one of them all and a very early start to spring too

Member 5     696 hours

Some fantasy cold charts from the extended GFS

Member 25     456 hours

Member 19     552 hours

Member 25     654 hours

Finally a very cold start to March too

Member 2     804 hours

[Jason H]

Quiet on here. ECM I take it has caused the sudden lack of postings? The usual inter-run wobbles. Still on track from what I can see.