Model output discussion 25th Jan - The final third of winter beckons..

[Day 10]

Upgrades from this morning. The times are slightly out on UKMO/ECM but the block slightly better positioned on all 3. I'm only looking out to 120 as it's an evolving situation.

GFS

UKMO

ECM

[nick sussex]

That highs going nowhere and now  the upstream troughing is sharpening up, probably in response to the MJO. Just need some lower heights to develop again in the northern Med.

[Johnp]

I'm usually as optimistic as they come, but I'm finding it hard to get excited about this.

There seems to be pretty good agreement on the pattern and yes, it's cold with flurries for a few days, but once again the deep cold stays on the continent and the high is too saggy.

Someone give me cause for optimism!

[SMU]

On it goes to day 9-

allignment not quite perfect however the atlantic has gone to lunch-

Edited February 4, 2017 by Steve Murr

[East_England_Stormchaser91]

1 minute ago, Johnp said:

I'm usually as optimistic as they come, but I'm finding it hard to get excited about this.

There seems to be pretty good agreement on the pattern and yes, it's cold with flurries for a few days, but once again the deep cold stays on the continent and the high is too saggy.

Someone give me cause for optimism!

The main thing as you said is the agreement is in place. Once we get the cold here, it will be down to sudden disturbances and shortwaves that could deliver sudden snow events. The devil will always be in the short term detail! 

[nick sussex]

1 minute ago, Johnp said:

I'm usually as optimistic as they come, but I'm finding it hard to get excited about this.

There seems to be pretty good agreement on the pattern and yes, it's cold with flurries for a few days, but once again the deep cold stays on the continent and the high is too saggy.

Someone give me cause for optimism!

Keep the faith, the ECM is a big improvement on the 00hrs run and as long as we keep the high centred sufficiently north then the MJO progression will give us another chance at the deeper cold.

[Gustywind]

Cold largely mixed out by day 8, but possible re-enforcements coming in for day 10. 

Iberian low looks like it's drifting north towards UK, big snow event potentially if it makes it.

[Frosty.]

1 minute ago, northwestsnow said:

ECM=

I see plenty to be optimistic about with this evolving situation..could be a cracker of a cold spell coming up. 

[SMU]

Finally snow @ day 10

coldest ever year in FI !!

Thats 7 days of easterlies from T72...

 

[Steady Easterly]

3 minutes ago, Steve Murr said:

On it goes to day 9-

allignment not quite perfect however the atlantic has gone to lunch-

Indeed, and further upgrades to come, everything is edging West run by run, classic scandi  high, fantastic to see.

[Wilxy]

Positive Run!

[Iceberg]

I still think the ecm is sending too much energy over the high after t120 and pushing the energy to Far East. 

Imagine the ec with the continuing scandy but with better positioning maybe an under cut and colder air. 

Thats what the models are hinting at currently. Still 24-48 hrs until they get there imho.  

[That ECM]

7 minutes ago, Johnp said:

I'm usually as optimistic as they come, but I'm finding it hard to get excited about this.

There seems to be pretty good agreement on the pattern and yes, it's cold with flurries for a few days, but once again the deep cold stays on the continent and the high is too saggy.

Someone give me cause for optimism!

It could be showing a bartlet and no hope of cold in sight. Good step forward for me tonight.

[Johnp]

4 minutes ago, nick sussex said:

Keep the faith, the ECM is a big improvement on the 00hrs run and as long as we keep the high centred sufficiently north then the MJO progression will give us another chance at the deeper cold.

I agree  - a Lazurus recovery at 240 hrs 

[Frosty.]

What a finish..roll on day 10

Another step closer..going to get very nippy

[markw2680]

4 minutes ago, Frosty. said:

I see plenty to be optimistic about with this evolving situation..could be a cracker of a cold spell coming up. 

Totally agree and tbh the closer we get to the reliable I can see further upgrades in this and more and more white stuff potential as we get closer. Roll on Wednesday when we should be on the cusp of something special..... I/we hope

[summer blizzard]

Not a bad end to the run with falling pressure and the flow even managing to become ENE in the south east. 

[Jason H]

The longer the Scandi High stays in situ, the more chance colder air will get advected West. Good models tonight for those of a cold, snowy persuasion.

[Johnp]

11 minutes ago, Johnp said:

I'm usually as optimistic as they come, but I'm finding it hard to get excited about this.

There seems to be pretty good agreement on the pattern and yes, it's cold with flurries for a few days, but once again the deep cold stays on the continent and the high is too saggy.

Someone give me cause for optimism!

Looks like my rare pessimistic post did the trick 

[Purga]

Nice ECM run ending with an upper trough crossing the SE.

Some different perspectives from WZ & Meteociel

 

850's

could cause some snowy disruption to the Capital if that verified!

A way off of course but nice to see / contemplate.

[nick sussex]

2 minutes ago, Johnp said:

I agree  - a Lazurus recovery at 240 hrs

Yes it got there in the end! No chance of the Atlantic getting in past T240hrs if that chart verified. We're trying to hold the high in place as the PV moves east/ne. That way we avoid any mild muck before the Greenie high appears later, hopefully. It might be more of a Greenland towards Scandi combo so an eastern based negative NAO.

[January Snowstorm]

As teits mentioned earlier classic easterly spells in the past always delivered cold and dry before the snow eventually arrived. Of course we hadn't the anguish of models back then just the 5 day ceefax!

Improvement today across all 3. It could go either way but we have a lottery ticket that this could become the big one

[Singularity]

It gets tricky beyond +168 has you have the better sourcing of cold from W. Asia but also that Iberian low pumping relatively warm air up from the Med. which mixes out the coldest uppers but I wonder if the surface situation would be so straight forward; less cold means less dense so some riding up and over is possible.

Also worth keeping in mind that the surface flow doesn't align with the isobars; it's very slightly to the right over the sea and more so over land. So not a bad attempt at retaining an easterly surface flow from the ECM 12z.

Day 10 just out and the much-mused disruption of that trough has taken place while the low to our south has started to edge east.

Very interesting and very feasible given the background forcing on the upstream pattern and the fact that lows over W. Europe don't tend to just sit there.

True what Chiono says that subtle adjustments will make a big difference to just how cold it gets for us; imagine if that low days 6-7 made it even 100 or so miles further east - you'd have a faster draw west of the frigid air from E Europe.

 

So longer-term we're now at a position of a short burst of westerly momentum firing a deep trough over to Siberia before renewed amplification in response to the 6-8 MJO buckles the jet and causes the next trough to get left behind, with a gap opening up into which the big block should then be able to build.

What this ought to lead to down the line, if applying broad-scale theories and overlooking complications - is that deep trough digging down into W. Asia while the block edges NW as the Atlantic is subdued again. If only it tended to be that simple!

 

I know I'm staring into the distance while cold is inbound for the mid-range, but unless a disturbance in the flow crops up and in the right place (note in - as in moving with - the flow, not one that works against it!), it doesn't hold much interest for a far-southerner such as myself.

[-uksnow-]

 

And so our Scandi high wheel of fortune spins to deliver at day 10 - Agree with what NS is saying, a little help from the MJO with an increasingly better upstream picture may eventually land us a bullseye...

[Stu_London]

Pendulum swinging back to an old school easterly where models (GFS worst offender) will suggest atlantic breakdowns only to back track in the 0-96 hr range.

Whether or not it's quite right for a snowy cold spell remains to be seen but it does look like we will have plenty of cold at the surface and as others have stated, get the cold entrenched and its likely that snow events will pop up, sometimes at very short notice.