Model output discussion - late November

[Mike Poole]

I don't think anyone's posted the clusters from the 0z ECM ens, so here at T240:

So the first two clusters, totalling about 70%, have the ridge - yes, weak or even weaker, but the resultant northerly could bring snow for some or more, so this is definitely one to watch for Election Day, you kind of think that majority solution roughly follows GFS op, and the other two the 12z ECM op.  

 

[SMU]

2 minutes ago, BLAST FROM THE PAST said:

Very odd run Steve...... never seen trough clearance so quick?!

 

BFTP 

Yeah a bit progressive within the overall theme of whats expected > although ECM / GFS both look plausible 168 > 192.

We just need a bit more cold air injected from the North circa -6c to be the right side of marginal -

[Jordan S]

2 minutes ago, Mike Poole said:

I don't think anyone's posted the clusters from the 0z ECM ens, so here at T240:

So the first two clusters, totalling about 70%, have the ridge - yes, weak or even weaker, but the resultant northerly could bring snow for some or more, so this is definitely one to watch for Election Day, you kind of think that majority solution roughly follows GFS op, and the other two the 12z ECM op.  

 

If I'm honest mike thats a very unsettled signal with flooding no doubt being the talking point yet again if things where to indeed play out like that.

[northwestsnow]

One thing we can say with some confidence is the Atlantic is coming back  after a 6 or 7 day holiday..

White or wet and where is impossible to pin down at the range considered-

GEFS look very good, hopefully the eps will be similar .

[Mike Poole]

9 minutes ago, jordan smith said:

If I'm honest mike thats a very unsettled signal with flooding no doubt being the talking point yet again if things where to indeed play out like that.

Yes, all roads would seem to have some fairly hefty precipitation potential in the mix, what sort of precipitation is open to question, but very difficult to pin any of that down from these plots unfortunately, particularly as they describe 51 runs, not one.  At this point 10 days out, I'm more interested in the options for the main pattern.  What, if anything, will fall from the sky is for much much nearer the time!

But for snow, could certainly be a high risk, high reward scenario upcoming based on today's output across the model suites...

Edited December 2, 2019 by Mike Poole

[Anthony Burden]

To my eye after this very mobile period which looks on the cold side mostly after short milder period.

Scandinavia looks prime for pressure rise in the 10 to 14 day period,just my opinion.

[Jordan S]

36 minutes ago, Mike Poole said:

Yes, all roads would seem to have some fairly hefty precipitation potential in the mix, what sort of precipitation is open to question, but very difficult to pin any of that down from these plots unfortunately, particularly as they describe 51 runs, not one.  At this point 10 days out, I'm more interested in the options for the main pattern.  What, if anything, will fall from the sky is for much much nearer the time!

But for snow, could certainly be a high risk, high reward scenario upcoming based on today's output across the model suites...

Quite a marginal scenario yes ofcourse that's if this synoptic pattern is indeed what is shown nearer the time in question we shall see how things develop.

That wet weather for Scotland on Thursday showing very well on the 5 day accumulated rainfall chart..

Edited December 2, 2019 by jordan smith

[West is Best]

Just looked at Election Day.

It's almost like someone has a wicked sense of humour. Bitterly cold: in places an ice day, with some snow.

[feb1991blizzard]

Slight improvement on EPS mean at end of run compared to 0z - cold slightly further south.

[northwestsnow]

EC mean is pretty good

[Mike Poole]

ECM 12z mean T240:

Looks promising to me.  The shape of the purple, blues over Russia, Scandinavia looks like there will be a fair few runs that bring the cold, and the Atlantic ridge also well supported, will be interesting to see the clusters.

T850:

Mean -2 south, -4 Scotland.

Edited December 2, 2019 by Mike Poole

[nick sussex]

Tonight’s models offer up the prospect of a soggy mess or something more wintry .

There’s an opportunity at day 7 on the ECM if the upstream troughing is not as deep and more amplified to get a weaker low moving se at day 8.

The GFS has the jet quite far south so in that scenario better possibilities could open up .

I think we’ve reached a scenario where things could tip either way with just some relatively smallish changes on a global scale .

 

[Frosty.]

Tonight's Ecm 12z ensemble mean longer term is definitely colder than the earlier 0z with the minus 4 line further south..could be a very interesting outlook beyond the current fine spell.

Edited December 2, 2019 by JON SNOW

[feb1991blizzard]

Good run for January on the latest CFS - plenty of snow events and cold.

[Mike Poole]

17 minutes ago, nick sussex said:

Tonight’s models offer up the prospect of a soggy mess or something more wintry .

There’s an opportunity at day 7 on the ECM if the upstream troughing is not as deep and more amplified to get a weaker low moving se at day 8.

The GFS has the jet quite far south so in that scenario better possibilities could open up .

I think we’ve reached a scenario where things could tip either way with just some relatively smallish changes on a global scale .

 

Yes, Nick, our first roller coaster of winter proper is on us right from the word go, re what will happen in 10 days time, with the election thrown in for extra spice.  Finely balanced on two fronts, both with the synoptic pattern, and the likely marginal snow prospects for some.  

Yes, the jet stream on the GFS is very far south on this run, T240:

I think this could be the winter of marginality, actually, if the jet stays largely south, and I think it will snow prospects open up for most, and flip side rain prospects. It will be really interesting model viewing over the next week or so as the current uncertainty is resolved. 

Edited December 2, 2019 by Mike Poole

[nick sussex]

1 minute ago, Mike Poole said:

Yes, Nick, our first roller coaster of winter proper is on us right from the word go, re what will happen in 10 days time, with the election thrown in for extra spice.  Finely balanced on two fronts, both with the synoptic pattern, and the likely marginal snow prospects for some.  

Yes, the jet stream on the GFS is very far south on this run, T240:

I think this could be the winter of marginality, actually, if the jet stays largely south, and I think it will snow prospects open up for most, will be really interesting model viewing over the next week or so...

Yes and if you look at the ECM spreads the largest is towards the west and sw on days 9 and 10 .

The actual troughing upstream is still showing quite a variation . The se tracking jet looks likely as the ECM spreads don’t suggest the PV will be blowing up to the north .

More likely it’s further to the nw.

[feb1991blizzard]

JMA only going one way from there, its a tiny tiny wedge just starting to ridge North but 100% will end in cold outcome in the later stages.

Edited December 2, 2019 by feb1991blizzard

[nick sussex]

1 minute ago, feb1991blizzard said:

JMA only going one way from there, its a tiny tiny wedge just starting to ridge North but 100% will end in cold outcome in the later stages.

That’s the thing Feb sometimes in here we get a bit hung up on strong blocking but a wedge of positive heights can still deliver .

Theres been some notable UK snowfalls with a more southerly tracking jet and those wedges helping to keep the UK on the cold side of the jet .

Now before there’s a stampede to the nearest sledge shop I’m not saying it’s going to happen here ! 

We’d need things to come together favourably and that’s often very elusive in UK winters !

[mb018538]

I must be the only one who thought the ECM looked pants at 240 just looks like a turbo charged jet piling across the Atlantic to me.....doesn’t look like anything to get our hopes up with there.

[feb1991blizzard]

Just now, nick sussex said:

That’s the thing Feb sometimes in here we get a bit hung up on strong blocking but a wedge of positive heights can still deliver .

Theres been some notable UK snowfalls with a more southerly tracking jet and those wedges helping to keep the UK on the cold side of the jet .

Now before there’s a stampede to the nearest sledge shop I’m not saying it’s going to happen here ! 

We’d need things to come together favourably and that’s often very elusive in UK winters !

Yes Nick - always feel even in a semi-mobile flow that if the wedge is very far West initially and the jet is fairly negatively tilted, then by the time the plunge gets to our shores it will be cold and potentially snowy, where as when the wedge starts quite close to us, unless its a classic undercutter Easterly with heights to the North East and a very buckled jet with troughs practically stalling out West like the classics then plunge will be too far East.

[Catacol]

12 hours ago, Nick F said:

 

The background atmospheric drivers on a more global picture in the northern hemisphere aren't particularly conducive to any big upheaval in the pattern in the next few weeks that could lock us into a blocked pattern, MJO looks like crawling slowly through phases 2-3 or staying in COD … so not really impetus for change forced by the tropics. The trop PV organising and expanding over northern Canada and Greenland - which will increase energy over the N Atlantic.

There is some debate about this out and around. The locked in IO pattern may well be masking the truth of MJO impact, and RMM plots plunging into the COD are not representing the magnitude of the fixed phase 2 pattern. In addition we have a substantial +EAMT ongoing through the next week or so, and this is likely to inject momentum sufficient to impact the pattern. How the vortex is going to react once the current displacement event ends is certainly up for grabs, but Pacific forcing may be more substantive in the second half of the month than might appear to be the case. GLAAM has also been rising. I don’t think we are going to see a dominant Greenland vortex later in the month.

Thats probably torn it. Cue a 1998 +NAO.

[Mike Poole]

5 minutes ago, nick sussex said:

That’s the thing Feb sometimes in here we get a bit hung up on strong blocking but a wedge of positive heights can still deliver .

Theres been some notable UK snowfalls with a more southerly tracking jet and those wedges helping to keep the UK on the cold side of the jet .

Now before there’s a stampede to the nearest sledge shop I’m not saying it’s going to happen here ! 

We’d need things to come together favourably and that’s often very elusive in UK winters !

I am, I think it is exactly what is going to happen for the first part of winter at least, southerly tracking jet NW to SE,  wedges of higher heights, and marginal snow events, less marginal as we head deeper into winter.  Given the model output we have been watching through late Autumn, this is the continuity solution...

And as I've said before on this thread, for me longer term it's then followed by a milder interlude, before a post SSW cold end to winter.  We will see...

[MATTWOLVES 3]

11 minutes ago, mb018538 said:

I must be the only one who thought the ECM looked pants at 240 just looks like a turbo charged jet piling across the Atlantic to me.....doesn’t look like anything to get our hopes up with there.

Looks OK to me. 

[mb018538]

5 minutes ago, Mattwolves said:

Looks OK to me. 

That will just result in chilly rain, it’s hardly good. Anyway, Matt Hugo has tweeted a similar thought re the Canadian vortex. Worth watching, people on here seem to just dismiss things they don’t want to happen when realistically they have a good chance of materialising.

[StretfordEnd1996]

1 minute ago, mb018538 said:

That will just result in chilly rain, it’s hardly good. Anyway, Matt Hugo has tweeted a similar thought re the Canadian vortex. Worth watching, people on here seem to just dismiss things they don’t want to happen when realistically they have a good chance of materialising.

It's only the 'mean' run that he posted - this isn't an actual run or anything its just the mean of all ensemble members

'Chilly rain' would be the case if the whole of the country lay below 50m or so - but there are some hills too - many of them

As I said earlier I'd be extremely surprised if Scotland/Northern England hills at the very least don't see anything next week. 

All to play for