Model Output Discussion - Staying cold into the new year

[bluearmy]

Thicknesses fall back by day 9 and whilst uppers drop marginally to -6/-8c, the flow comes away from onshore much of the precip goes from wet to white 

[Tim Bland]

1 minute ago, Kasim Awan said:

It's a good evolution for wintry conditions.

P S. it was an IMBY post.

It’s a very IMBY post as most in the north / north west still have rain on this particular run. It Gets there in the end, but I’m praying it ends up a degree or so colder so most can see snow rather rain next week

[Snowman.]

1 minute ago, Kasim Awan said:

It's a good evolution for wintry conditions.

P S. it was an IMBY post.

Might be better to specify that tbh, many are getting more and more rilled up with all these snow posts..

ECM is nice in that the Russian high is marching west, real cold and snow will come if it makes it far enough.

[Mike Poole]

Sorry - double post

Edited December 30, 2020 by Mike Poole

[Day_9]

Just now, Allseasons-si said:

ECM At 216 would be cold under that slack flow,day ten should be a snow maker with that low disrupting south.

Back to 10 days away!  Interesting to see snow row numbers getting  pushed back into the same T240 timeframe...... . Overall though is there not widespread consensus on the trend to a decent spell of below average temps?

[Kasim Awan]

192-208h brings a reasonable intensity snow band across the country.

Over depending on snow accumulation charts at that range is futuile imo. The synoptic trend which this run is aligning to is highly wintry, so this joins the "snow party" in terms of a statistical trend.

[radiohead]

Day 10 could be interesting in places...

Blizzards and heavy rain and wind oh my

 

Edited December 30, 2020 by radiohead

[northwestsnow]

5 minutes ago, Tim Bland said:

Rain rain and more rain next week on the ECM next week unless you are on very high ground. Just need those DPs to 1c lower I reckon and eastern areas would be buried ! Sorry BA we were typing at the same time...both thinking the same thing ?

Owww  looks good IMBY !!

I took a few shots today ... sub zero day with partial snow cover ...

Not overly keen on EC day 9 ...

[Gregulator]

If that big Russian high moves northwards to the pole would the big purple slug slide underneath across across, or is that too simplistic?

[Harsh Climate]

240h I've seen worse.

[mountain shadow]

Disappointing end to the ECM after a promising day 8 chart as a deepish low forms to the North West with a West based -NAO.

Real cold still in FI.

[Cold Winter Night]

I like this EC at 240.
Heights growing over Svalbard, heights beginning to drop over Kazakhstan.

[Ali1977]

8 minutes ago, bluearmy said:

And the snow and precip totals by day 8 tell their own sorry tale for much of the country - you’d think we’d be buried !!

   

Those charts are as much use as tits on a fish - there would be plenty of snow about with that chart surely - especially on the higher ground!! 

[Tim Bland]

2 minutes ago, radiohead said:

Day 10 could be interesting in places...

 

Yes, snow showers coming south day 9 then more persistent north of a Brum day 10

[Djdazzle]

So after sifting through contradictory posts, the ECM flatters to deceive. There is far too much hyperbole on here (at both ends of the scale).

Cold rain with a raw wind doesn’t do it for most folk!

And it seems like any prospect of deep cold remains at day 10!

 

 

[Sweatyman]

2 minutes ago, Ali1977 said:

Those charts are as much use as tits on a fish - there would be plenty of snow about with that chart surely - especially on the higher ground!! 

Well apparently not.

[SMU]

19 minutes ago, bluearmy said:

So ecm has precip across se england from day 5 to day 7. Uppers vary between -4 and -7. Lowest thicknesses only 526dam.  Not a flake 

that’s directed at those posters who think it’s only about the uppers and that -5/-7 with a flow off the n sea will deliver snowfall ....its way more complicated than that 

Yep I set my benchmark @-7.5 earlier. UKMO safe. ECM not safe.

UKMO needs to be right !!

[Sweatyman]

2 minutes ago, Tim Bland said:

Yes, snow showers coming south day 9 then more persistent north of a Brum day 10

Haha 1cm off that Brilliant stuff yeah love it

[Mike Poole]

JMA 12z has gone with the omega block solution at T192:  

All roads lead to Rome...or should that be cold.  What is shown on the models are once in a decade for the UK.  So much so, that I haven’t seen them before, I started model watching in 2011 so after the Dec 2010 freeze.  And I haven’t seen what we are seeing at the moment.  So while I understand the scepticism of some who haven’t seen a snowflake yet, just patience please, because I can’t see a way it isn’t coming...

[Djdazzle]

3 minutes ago, Ali1977 said:

Those charts are as much use as tits on a fish - there would be plenty of snow about with that chart surely - especially on the higher ground!! 

That’s why people were saying last week when discussing this week. Very little precipitation this week, except for a lucky few.

[PolarWarsaw]

2 hours ago, Met4Cast said:

GLOSEA is showing a strong SPV reversal with u-winds not really recovering until the end of January.

Slowly slowly..

 

Disappointed, in fact negativity at all is probably a little bit far-fetched for this specific chart. But I have to say I'm a little 'disappointed' to see zonal winds organising again by the end of the month. I can't help but feel the massive split touted in the models and by others around the internet is clearly now not happening and is turning rapidly into a displacement episode. Obviously as a starting point clearly there's a great thing, but I was rather hoping we would be talking about the effects of a mid-season SSW right the way through the end of February - IE, a vortex never recovering. 

There's not been half as much talk about an SSW in the last few days and actually, that might be because it's about to start happening in the atmosphere and this is a period of waiting and watching, but I do also think that things look a lot less exciting than perhaps they did a week ago and that's a contributing factor. 

To be honest though, that's not a bad thing. I feel like the charts/output we currently see in the next 7-10 days might actually bear the 'cold spell of the winter'. We do spend a lot of time watching FI throughout our winters and the reality is, we might actually be on the cusp of something fairly notable, without the help of an SSW.

The more and more I look at the charts, the more an SSW is actually making me a little worried. Not in terms of what it can bring, but more that this is 2020 and the opposite is probably more likely to happen. We have been in such an unusual repetitive pattern for about 6 weeks now that I'm almost tempted to ask an SSW to hold off for a couple of weeks yet, so we can persevere with this current pattern that keeps teasing us with cold enough uppers to bring what would still be a 1-2 week, very cold and potentially snowy pattern. It wouldn't even be ironic, for an SSW to bring us BBQ weather, it's just standard for the UK - you expect the worst of every scenario. 

My message tonight would be to focus on what is showing in the output in the next 10 days. Yes as we speak it looks marginal, but if anything like tonight's ECM 192 or last nights 18z GFS verifies then I would put a lot of money if offered evens or more on the period prior to an SSW downwelling being the coldest spell of this entire winter. With that in mind, it does have to be said that today's models have moved away, on the whole for anything of interest in that time period - so it's one to watch for now. 

Focus on the models and with a bit of luck we might not actually 'need' an SSW to give us something very exciting nationwide at the surface. 

PS - I've had two separate falls of 1-3CM's, in day light with -4 uppers this week at 70M's...so I certainly wouldn't be TOO hung up if charts show rain. It won't take much to turn that all snowy - much like it won't take much for us to miss out at all. 

Edited December 30, 2020 by PolarWarsaw

[Kasim Awan]

5 minutes ago, Tim Bland said:

It’s a very IMBY post as most in the north / north west still have rain on this particular run. It Gets there in the end, but I’m praying it ends up a degree or so colder so most can see snow rather rain next week

You and others are failing to see the bigger picture. The general evolution D6 on wards with the retogression, Artic plunge & maritime influence is generally one which produces good snow risk. Plus, who said we were looking at widespread heavy powdery snow? No one, including me, have. So I suggest please, keep this realism in mind.

Coming down back to earth, this general trend towards a mixing cold airmass is certainly interesting from a snow perspective, that doesn't mean I'm forecastinf widespread powder snow. However, that isn't completely outside possibilities.

A more informative post here as I feel many misinterpreted / took my punch line post far too seriously. No worries, let's move on.

[Tim Bland]

1 minute ago, Ali1977 said:

Those charts are as much use as tits on a fish - there would be plenty of snow about with that chart surely - especially on the higher ground!! 

These charts are using all the data from the run eg uppers, thickness and DP etc to decide if it’s rain or snow. If anything they have been guilty over the years of over doing the snow. In most cases where the uppers are -7 the DP is 1 or 2 degrees so it can’t be snow on low ground I think we will be ok though as there has been a trend to drop the uppers / DP slightly as we near the actually date. We are very boarderline and 1c is all we need

[Daniel*]

I recommend people don’t take ECM too literally for small details outside very near term, with showing rain/snow, better to look at high res models such as ARPEGE which shows supportive dew points for many in contrast to ECM. I know for especially maritime places like Cornwall especially the ECM model severely overdoes Atlantic modification, quite often with cold nights ect, the higher res models are much better to look at in that regard. 

[Mr Frost]

Latest UKV snapshots for 04/01 15:00

 

At least there is a risk of heavy snow showers there - marginal yes but it’s getting to the stage some folk in SE England are getting a wee bit desperate - which is fair enough.

If I was living down there I would rather have a risk of wintry precipitation than absolutely nothing at all - above charts have a bit of potential! Few tweaks here and there nearer the time and you are in business. 
@Kentspur @Tim Bland @Daniel* I am rooting for you lads - see you posting on here daily and always full of optimism and glass half full! Let’s hope you get the rewards this Winter. (That goes for anyone else who is snow starved!) 

@bluearmy loving those ECM snow charts for IMBY - keep them coming mate. 

Edited December 30, 2020 by Mr Frost