Model output discussion - is the beast awakening?

[Stu_London]

1 minute ago, kold weather said:

At least we do still draw in an ok easterly for a time.

There were some runs which almost instantly build it in. Like having a UK high fully in place by 168hrs for example.

This run though is pretty close to what I'd say the average of the whole 12z suite showed though, which broadly was a short blast from the east followed by pressure rise nearby.

I;d say we are still set-up well at 240hrs but it will be a close run thing as to how that evolves from there on. Could easily see a true beast towards the end of this run try and happen.

Uppers are eroded quite quickly on this run but like some of the best easterlies have been at the second bite. 2018 was to a degree. 

[mountain shadow]

9 minutes ago, CreweCold said:

It is not variations on a theme.

We've gone from deep seated, low thickness E'ly to a brief E'ly waft followed by a UK HP within 48 hours. Who's to say the downgrade in synoptics will stop there?

Usually it end up as a Greek tragedy for us, not the Greeks.

[Snowman.]

The 18z isn't the ECM which is all that matters to me 

[sunnijim]

1 hour ago, kold weather said:

I wouldn't be shocked if one of the next few GFS runs develops a UK high rather than Scandi high. It has been showing on all three of the main ensembles suites, we'd be lucky if it doesn't show itself at some point on the op, even if it does go well.

Just thought I'd put that put there as I'm sure there will be some meltdowns if that happens!

 

There was talk of that solution in a M.O update, of High pressure centred over Northern Britain mid February onward.

Looking at the output you can see that is a viable solution around that timeframe.

Previous you would have the Arctic High moving South and setting up shop over Northern Britain.

Obviously exact positioning would be crutual for prolonging any feed from the East for the South of England.

Before that,we 'should' have time to import bitter air/ snow?

Edited January 30, 2021 by sunnijim

[Snowman.]

1 minute ago, mountain shadow said:

Usually it end up as a Greek tragedy for us, not the Greeks.

Usually we're asking for notherly corrections not the other way round 

[Kirkcaldy Weather]

If it’s the beast type cold that some are searching for the chances of that could be with what is being hinted as the 2nd attempt and it might be a similar way to how the BFTE developed. There’s enough changes with how the high develops firstly but why the negativity appears so quickly in here given the charts we are seeing doesn’t make much sense to me.
current gfs run (whether it manages it on this run we will see as it is a tricky pattern to accomplish but I wouldn’t rule it out)  > before BFTE 

[saintkip]

Nowhere near as good as the 12z. But a lot better than the officials at at Mary’s tonight 

[kold weather]

1 minute ago, Stu_London said:

Uppers are eroded quite quickly on this run but like some of the best easterlies have been at the second bite. 2018 was to a degree. 

I think Feb 1991 was a classic example, it took about 3 bites of the cherry on that occasion. There are some similarities with the large LP to our NW and the large upper high to our NE in FI on this run.

Of course past 120-144hrs I'd not read too much into it anyway!

BTW it might be worth noting that on the GFS version we'd need the HP to collapse to some extent towards the UK to get an easterly, otherwise much of the country would stay in a flabby airflow which won't be cold enough on its own.

[Singularity]

A bit of own judgement is needed when you see a chart like this - 9 times out of 10 a low slides southeast into Europe from that position, as opposed to what the run goes on to show.

Hopefully this analysis will still have at least loose relevance to the latest model output come this time tomorrow!

[Griff]

GFSP doing its thing, 126

[BLAST FROM THE PAST]

Heights to NE, disrupting trough over UK and sharpening Atlantic ridging behind.  The model prob won’t but that is classic Scandi HP and Easterly to follow territory

 BFTP

Edited January 30, 2021 by BLAST FROM THE PAST

[Mike Poole]

GFS 18z // looking very good at T126, connection with the arctic high and that troublesome low kicked aside to the SE.  Lovely.

[Snowman.]

1 minute ago, kold weather said:

I think Feb 1991 was a classic example, it took about 3 bites of the cherry on that occasion. There are some similarities with the large LP to our NW and the large upper high to our NE in FI on this run.

Of course past 120-144hrs I'd not read too much into it anyway!

BTW it might be worth noting that on the GFS version we'd need the HP to collapse to some extent towards the UK to get an easterly, otherwise much of the country would stay in a flabby airflow which won't be cold enough on its own.

Looking back through Feb 2013, you can see there is multiple attempts at getting heights north and establishing an easterly flow.

And we all know what fallowed in March.

[MKN]

2 minutes ago, Snowman. said:

The 18z isn't the ECM which is all that matters to me 

Spot on. Ecm is different altogether and not very good for the UK. Wereas the gfs is very good, granted 18z not as snowy as its 12z but its just a slight alternative to the general theme. 

[Purga]

Mmm... building up to a powerful easterly again in FI.

Watch the trigger LP drop SE

Edited January 30, 2021 by Purga

[kold weather]

1 minute ago, sunnijim said:

There was talk of that solution in a M.O update, of High pressure centred over Northern Britain mid February onward.

Looking at the output you can see that is a viable solution around that timeframe.

Previous you would have the Arctic High moving South and setting up shop over Northern Britain.

Obviously exact positioning would be crutual for prolonging any feed from the East for the South of England.

Before that,we 'should' have time to import bitter air/ snow?

The way to think about the UK high if it were to form is we are in a position where we could very rapidly import cold air back in from the north or east should the synoptics shift again at some point. Given how weak the PV is, I'd be surprised if the HP just sat in one place for too long, regardless of where it ends up forming.

It may not look as good, but it might put us in a healthy position, especially as many of the coldest evolution have developed from just such a setup.

[Continental Climate]

I'm with crewe here we have had quite severe downgrades in the last 48hrs. There is no point in sugar coating this. The usual places will do quite well but those in the south and west will likely miss out here as the 850s have went from -12 to currently -8. I hope I'm wrong but don't think I will be. 

[northwestsnow]

I mentioned the cold pool to our NW earlier on 18z, and along comes a rare snowy NW ly.

Edited January 30, 2021 by northwestsnow

[Daniel]

Some will be happy to know the mean brings the colder air in quicker than the op 

[saintkip]

2 minutes ago, MKN said:

Spot on. Ecm is different altogether and not very good for the UK. Wereas the gfs is very good, granted 18z not as snowy as its 12z but its just a slight alternative to the general theme. 

You say slight alternative, it’s gone from 20cm’s of snow to nothing, that’s a pretty big change

[Don]

Just now, Snowman. said:

Looking back through Feb 2013, you can see there is multiple attempts at getting heights north and establishing an easterly flow.

And we all know what fallowed in March.

Yes February 2013 was a close but no cigar month.  After the January cold spell ended, there was much hope for a cold/very cold February but it never quite pulled it off, although at 3.2C it was colder than average (a bit like this month in many ways).  However, as you say the rest is history with the March that followed!

[Griff]

1 minute ago, Daniel said:

Some will be happy to know the mean brings the colder air in quicker than the op 

Over analysing this run beyond this point is futile. 

The pattern holds, no drama. 

Thanks. 

Good night. 

[kold weather]

3 minutes ago, Singularity said:

A bit of own judgement is needed when you see a chart like this - 9 times out of 10 a low slides southeast into Europe from that position, as opposed to what the run goes on to show.

Hopefully this analysis will still have at least loose relevance to the latest model output come this time tomorrow!

Yes mate, indeed I said earlier when the run was about 144hrs out that I expected an Atlantic attack from the SW between 216-240hrs, but it kinda fizzled before it even got close as the forcing shifted further NW towards the big upper lobe near Greenland.

It did have some decent support from all 3 major ensemble suites though.

I'm still more concerned that we may end up seeing the HP form too close to the UK and any easterly ends up over Europe. Certainly wouldn't be the first time that has happened.

Though even then, through dint of the evolution we'd get a quick fire easterly shot across the bows i suppose.

[Stu_London]

1 minute ago, Daniel said:

Some will be happy to know the mean brings the colder air in quicker than the op 

The op also exits the cold upper earlier than the mean

[Snowman.]

Just now, Don said:

Yes February 2013 was a close but no cigar month.  After the January cold spell ended, there was much hope for a cold/very cold February but it never quite pulled it off, although at 3.2C it was colder than average (a bit like this month in many ways).  However, as you say the rest is history with the March that followed!

Yup, few examples for everyone else below.