Model output discussion - is the beast awakening?

[Chesil View]

3 minutes ago, bluearmy said:

back end op - day 10 

 

It means the Atlantic won’t become quiet .....hopefully a greeny wedge can deflect it far enough to the south 

That's good we don't want the Atlantic too quiet . We need sources of moisture to liven up the incursions from the south west that aren't  expected to make much inland progress as per meto update.

[That ECM]

3 minutes ago, Don said:

Not the best for cold then but subject to change and could be a high risk/high reward scenario, would you say?

I think it needs to sort T120-T144 first. 

[danm]

17 minutes ago, Stu_London said:

Amazing how quick the weather flipped after beast 2 - I recall playing golf in shorts and t shirt a week later and coming across drifts that had accumulated in the bunkers 

Yep we transitioned almost immediately from a freezing March to a very warm/hot April to early August. I remember thinking, I wish our seasons were always like this - cold and snowy winters, hot and sunny summers, quick transition between the two - very continental!

[ICE COLD]

The mean is catching up with the GEFS. Looks really good with the easterly now

T144 to 216

[Nigerian Prince]

On the ECM, after spending 4 or 5 days stuck over the UK, the low pressure suddenly rockets 1500 miles in 24 hours to the Ukraine, definitely one for the bin, I think.

Location Battersea London, Gender Male.

[Frank Trough]

18 minutes ago, JamesL said:

Hmmmm we had the coldest March day on record at -5 in Tredegar with drifts up to the guttering 

Pretty historic here lol 

I find all the March talk tiring. Everyone knows you can get snow and it’s more likely than December. The point is it takes something exceptional to make it worthwhile. 2013 was amazing. And it won’t be repeated any time soon. 

[East_England_Stormchaser91]

I’m glad the ECM is coming back more in line with the UKMO and GFS. 

In the past, it’s always been the UKMO to be the most “glass half empty” model. No UKMO, no party. 

[Mike Poole]

Well on the clusters at that key T120-T168 time window, there are two, one where the low sticks around in some form in the vicinity of the UK, and one where it doesn’t.  33-18 in favour of the low sticking:

This is so important for the UK, it isn’t really worth looking any further until this is resolved.

Edited January 31, 2021 by Mike Poole

[Don]

3 minutes ago, That ECM said:

I think it needs to sort T120-T144 first. 

Very true, just talking about another possibility down the line.

[Battleground Snow]

Some cold runs in the spread, -11's. They are starting to look like what the GEFS have been showing for a while. Op almost an outlier at day 7 and 8.. still scope for improvements I think.

[northwestsnow]

EC mean is a cracker to be fair ..

[PiscesStar]

6 minutes ago, Frosty Winter said:

To my surprise the ECM 12z ensemble mean looks fantastic at t168 with a decent easterly wind!

We needed the ECM to show this and it has!! 

[Catacol]

33 minutes ago, jam said:

The sun stronger argument surely died a death in March 2018 ?  

Indeed. Lesson learned - and March 13 was none too shabby either.

But I think it is really important that folk realise the context this year is not (yet) anything like 2018. The Beast in 2018 was a direct creation of a significant vortex split, and such was the magnitude and angle of that split and the very swift downwelling response that it became very difficult NOT to end up with a massive easterly. It was an extraordinary event. I had half hoped for something similar earlier this month, but the warming wasn't quite strong enough.

What we have coming up is a tropospheric led pattern with a vortex up top that is forecast to recover a bit - and isn't split. That isn't to say that we won't end up with an easterly - I'm pretty sure at stages this coming month we will have that easterly....but we are also going to have Atlantic influence and that means battleground events a plenty. Different setup, less chance of that long draw easterly. In 2018 do people remember how one phase of cold ended? A low pressure travelling east to west actually shot too far out into the Atlantic from Spain. It was utterly bizarre. The vortex split caused the entire circulation to travel the wrong way, and as that low ended up in the Atlantic against the initial forecast it was a bit of a sickener. It was still awesome....but by golly it could have been drifts up to the armpits had that low held fast.

I don't think we are going to get anything like that this time around, but the longevity of snow opportunities looks striking. Warm bumping and sliding into cold....brief warm up.....cold digging back in.....more bump and slide. Chances for an easterly to hold fast for a few days certainly possible too.

I'm seeing chances for Feb 91 and Feb 96 in the approaching mix. I'm not seeing a 2018 style vortex split in the forecast for this season now. Would love to be wrong though - 3 cold months on the bounce would be awesome.

 

Edited January 31, 2021 by Catacol

[That ECM]

Just now, Don said:

Very true, just talking about another possibility down the line.

Yes agreed and all data to be judged. Just got the hump with the ecm recently.

[Djdazzle]

1 minute ago, Certain kind of fool said:

I find all the March talk tiring. Everyone knows you can get snow and it’s more likely than December. The point is it takes something exceptional to make it worthwhile. 2013 was amazing. And it won’t be repeated any time soon. 

I’d be happy with that as March is a spring month and I’ll be looking for warmth from the models.

Good ECM mean - shows the potential for an easterly.

 

[Stu_London]

1 minute ago, Battleground Snow said:

Some cold runs in the spread, -11's. They are starting to look like what the GEFS have been showing for a while. Op almost an outlier at day 7 and 8.. still scope for improvements I think.

Taking the OP and the ensembles together, its a very positive 12z run, tempered only be the large spread relatively early, which suggests the model struggling overall to get a handle on things

[northwestsnow]

One could argue that the much improved det was an outlier ...

[chris55]

4 minutes ago, Battleground Snow said:

Some cold runs in the spread, -11's. They are starting to look like what the GEFS have been showing for a while. Op almost an outlier at day 7 and 8.. still scope for improvements I think.

When a picture paints a thousand words.

 

 

[Methuselah]

16 minutes ago, Bristle boy said:

March '18 - Minus 2c at 2 oclock in the afternoon in balmy Bristol, with snow still falling. Historic, for sure.

-5 over here, Bris... Driving snow and bloody freezing!

[phil b]

1 hour ago, swilliam said:

You should try the Metdesk site then - it comes out in 3 hour steps

https://wxcharts.com/?panel=default&model=ecmwf,ecmwf,ecmwf,ecmwf&region=uk&chart=overview,accprecip,850temp,2mtemp&run=12&step=003&plottype=ens&lat=52.083&lon=-1.017&skewtstep=0

Or windy.com

1 hour increments up to 3 days out then 3hrs after that.

Windy as forecasted

WWW.WINDY.COM

---

Wind map and weather forecast

 

Edited January 31, 2021 by phil b

[Don]

25 minutes ago, That ECM said:

Yes agreed and all data to be judged. Just got the hump with the ecm recently.

Haven't we all lol!  Overall, despite my moans earlier it's not looking too bad this evening and at least the ECM has improved.

Edited January 31, 2021 by Don

[Froze were the Days]

23 minutes ago, Catacol said:

3 cold months on the bounce would be awesome.

Thought December 2020 was more or less average at 5c?

[That ECM]

1 minute ago, Froze were the Days said:

Thought December 2020 was more or less average at 5c?

Jan feb March

[kold weather]

So before the 18z roll through, just thought it'd be interesting to see how well the models reflected todays set-up vs what the model expectation was. This is for those of us who are getting caught up in what 168hrs is going to look like and assuming that the runs are going to either make or break a cold spell this far out.

ECM at 180hrs out from today (24th January 00z):

GFS at 180hrs out on 24th January

Now lets try just 108hrs out:

ECM at 108hrs out on 27th January:

GFS at 108hrs out on 27th January:

Reality today:

The models at 180hrs did a pretty poor job on the position of that low and a shocking;y poor job on its orientation, it extended far more ESE than expected.

They got a little closer but were still WAY off on intensity (981mbs vs sub 965mbs at just 108hrs) and both, whilst closer, still did a pretty poor job on the shape of the LP and its oreintation.

So what lesson should we take?

Whilst the 72-120hrs does appear to be firming up towards a more delayed withdrawal of the LP, it can be seen that both the GFS and ECM actually agreed pretty closely at both 180hrs and 108hrs on the broad pattern.

There was consistency broadly for the idea in the models...And both were WAY wrong even at just 4 days lead time. You can see the trend however towards extending that primer low further to the SE.

Therefore:

FI at the moment is no further than 4, maybe 5 days at most. You can have maybe some confidence that the trend is slower withdrawal of the LP but no more.

Also, I hope these charts show why it'd be foolish even if the models do come into agreement to write the set-up off. Even the GEM is well within the margin of error where a bad chart can flip to a stunning chart that far out. Equally the reverse is true as well.

Edited January 31, 2021 by kold weather

[Froze were the Days]

3 minutes ago, That ECM said:

Jan feb March

Blimey! we're not getting too far ahead of ourselves then...most interesting thing to me is if this January we can get an anomaly of -1c on the 61-90 CET series for a winter month (last time Dec 2010)