Model Output Discussion - Cold spell ending - what next?

[daz_4]

GFS Op is a huge outlier for Central Europe with that cold pool.

[Vikos]

6 minutes ago, daz_4 said:

GFS Op is a huge outlier for Central Europe with that cold pool.

Or trendsetter for the new chase? This mild interlude isn’t for long…

[Chesil View]

All models seemingly going for pressure to rise to our east towards months end.

Yet as the various models suggestions show.

When it comes to advecting cold/snowy conditions towards our shores The exact position and orientation of a Scandi high is absolutely crucial.

Scandi Highs are a high risk but not always high reward scenario for the UK.

 

[AO-]

19 minutes ago, Vikos said:

Or trendsetter for the new chase? This mild interlude isn’t for long…

The EPS of GFS downgraded a little compared to yesterday. First want to see the EPS of EC to see where it is going.

[Eagle Eye]

Unlikely pattern to verify but there is some support for a Scandi high in phase 5 only if the momentum forced into the high is strong enough otherwise it's just quite a flat ridge into UK-Scandi slightly tilted like the GFS mean has it as. 

However this pattern is not entirely without support and we've seen multiple runs showing this is possible. Early February is very much the start of this potential for a return to cold potential after all as I've said before. 

[Weather-history]

37 minutes ago, KTtom said:

Lets hope EC continues with its reputation for day 10 charts, because this mornings is a shocker if its cold we're after..its not just our location look at the uppers to the east and north east

Deep cold airmass, yes but that does not always equate at the surface eg 26th January 2017.  I actually saw falling snow here that day and the maximum was just 1°C

[Cymro]

1 hour ago, AO- said:

Agree, but I think you misunderstood me. There are no-15/-20s  in the northeast. I'm affraid the cold will 'dissolve' with the sun getting more power. 

Far too early to be worried about the sun's strength, if it were the 20th of Feb Id sympathise but it's mid winter. Cold pools develop quickly over Scandi under High pressure at this time of year. 

[markw2680]

50 minutes ago, Ali1977 said:

Day 10s, I think we are staring down the barrel of our next chase - and it isn’t at day 16 on the GFS which is nice!! 
This time we are chasing the easterly or north easterly - rather than getting watered down like a northerly these can often quickly establish into something far colder

Yes they can and let’s hope this is the case, but just as likely imo is they completely disappear at the flick of a switch, need to hope the trend keeps it over the next few days and then just maybe there will be the next chance of something cold and d.r.y. ?

[AO-]

The EC EPS of this morning compared to yesterday. Dry and sunny weather with probably the biggest chance of a block over our heads. 

[nick sussex]

The GFS more interested in the Scandi high earlier .

The models all sing from the same hymn sheet in terms of overall pattern . Pressure rises to the ne and still an angry looking PV . We await to see which one wins out .

The ECM may just be a timing difference v the GFS and we are seeing the pull back of low heights from the  ne and Svalbard region although the ECM does keep the more rounded PV at day ten .

You generally want to see the more sausage shaped PV orientating ne sw initially.

 

[AO-]

1 hour ago, LetItSnow! said:

Not something I’d be concerned about in late January and early February to be honest. If it were a month down the line, perhaps. It could be worse. 

Maybe I'm a perfectionist, but I am looking for something like member 15 

Edited January 19 by AO-

[Mike Poole]

ECM clusters this morning, T192-T240:

Firming up now on the extension of heights north into Scandi.  Both clusters show this.  The first cluster is actually showing a good position for the centre of the high 500hPa heights by T240, getting there on surface pressure contours (27 members)..  

T264+:

Cluster 1 holds the Scandi block in a good position, cluster 2 collapses back to +NAO, clusters 3 and 4 risk ending up with a UK high.  This might retrogress on cluster 3 beyond the timeframe.  

[bluearmy]

Looking like quite a struggle to get enough amplification on a scandi ridge with the spv likely to be close to Barents/NZ and the tpv Canadian segment looking to extend  itself towards that locale. 
a murr sausage would work and if we could somehow get some lower heights to run clockwise around a ridge with an associated cold pool then that would possibly be the best we could hope for in next 13-16 days. 
currently ens guidance looks like any scandi height rise likely to be extended to sceuro and followed by an mid Atlantic height rise that draws the euro heights west. again, no indication what amplification may be possible on that but it’s well into week 3 so out of range of ens 

Edited January 19 by bluearmy

[E17boy]

Morning peeps

hope you are all well. A lot of comments on possible heights building over Scandinavia as we get into the ending of January. However I would say a lot has to fall in place for us to get the perfect setup for cold from the east. It depends on the orientation of the high and its positioning., also how strong the high can hold for. Many of times we have seen a Scandinavian high set up but we have ended up with a 1 day easterly wind and a few snow grains in the east and then itss gone. We don’t want the high to set up too far east as this will do us no good. So great caution is still needed with this type of setup. The jigsaw has to all fall in place, tentative signs that this may bring a pattern change to cold but too far out to make any judgments yet. The main focus for the next week will be the wind and rain and after that it’s all about how the trends play out.

have a great Friday all

regards 

[Anthony Burden]

Morning all,The break down to the Atlantic looks short and stormy with possible damaging winds,after then high pressure takes over how it evolves and positioning still up for grabs but a continental air feed looks the form horse 850 hpa aloft will chop and change but if an east /northeast air stream gets established cold /verycold February could be on the cards also Geffs ensembles operational wants to keep heading south albeit not the average mean.

[sebastiaan1973]

38 minutes ago, AO- said:

The EC EPS of this morning compared to yesterday. Dry and sunny weather with probably the biggest chance of a block over our heads. 

Yes, it does around day 10, later on the anticyclone moves to the west.

[AO-]

17 minutes ago, Mike Poole said:

ECM clusters this morning, T192-T240:

Firming up now on the extension of heights north into Scandi.  Both clusters show this.  The first cluster is actually showing a good position for the centre of the high 500hPa heights by T240, getting there on surface pressure contours (27 members)..  

T264+:

Cluster 1 holds the Scandi block in a good position, cluster 2 collapses back to +NAO, clusters 3 and 4 risk ending up with a UK high.  This might retrogress on cluster 3 beyond the timeframe.  

Given the fact that a Scandiblock is fairly represented in Fi, it doesn't seem very fruitful. In the EPS I just posted there aren't many members with Max temperatures just above or below zero. This implies that the coming week destroys the cold that has been built up. 

[Nick F]

8 minutes ago, Mike Poole said:

T264+:

Cluster 1 holds the Scandi block in a good position, cluster 2 collapses back to +NAO, clusters 3 and 4 risk ending up with a UK high.  This might retrogress on cluster 3 beyond the timeframe.  

None of the extended clusters showing Atlantic troughing / upper flow energy undercutting high pressure building north over Europe that would hold a Scandi high in place for a sustained enough period to bring cold air our way though, so the high would eventually collapse. My worry is the lack of low heights especially over Iberia from Atlantic troughing undercutting, as well as further east over the Mediterranean Basin from undercutting of cold air from the NE, will mean we end up with a large Scandi-Euro High of little benefit to coldies in the UK other than some surface cold perhaps.

But, we know these clusters can change, so more runs needed. But I'd feel much happier if we saw troughing extending from the Atlantic over Iberia rather than the semi-permanent Azores ridging there. Extremely dry across parts of southern and eastern Spain this winter so far, due to lack troughing extending from the Atlantic over Iberia with ridging dominating.

We can get away with cold air undercutting high pressure over Scandinavia from the NE into southern Europe to lower heights over the central Med to bring a brief cold easterly, but prefer of the Atlantic troughing undercuts too to make it more sustained.

[sebastiaan1973]

3 minutes ago, Nick F said:

None of the extended clusters showing Atlantic troughing / upper flow energy undercutting high pressure building north over Europe that would hold a Scandi high in place for a sustained enough period to bring cold air our way though, so the high would eventually collapse. My worry is the lack of low heights especially over Iberia from Atlantic troughing undercutting, as well as further east over the Mediterranean Basin from undercutting of cold air from the NE, will mean we end up with a large Scandi-Euro High of little benefit to coldies in the UK other than some surface cold perhaps.

But, we know these clusters can change, so more runs needed. But I'd feel much happier if we saw troughing extending from the Atlantic over Iberia rather than the semi-permanent Azores ridging there. Extremely dry across parts of southern and eastern Spain this winter so far, due to lack troughing extending from the Atlantic over Iberia with ridging dominating.

We can get away with cold air undercutting high pressure over Scandinavia from the NE into southern Europe to lower heights over the central Med to bring a brief cold easterly, but prefer of the Atlantic troughing undercuts too to make it more sustained.

It is clear from the Plume of the De Bilt that there is indeed no cold available. 

[Snowboy111]

1 hour ago, Chesil View said:

All models seemingly going for pressure to rise to our east towards months end.

Yet as the various models suggestions show.

When it comes to advecting cold/snowy conditions towards our shores The exact position and orientation of a Scandi high is absolutely crucial.

Scandi Highs are a high risk but not always high reward scenario for the UK.

 

I’d take it over a Greenland high any day of the week….

[Alexis]

2 hours ago, daz_4 said:

GFS Op is a huge outlier for Central Europe with that cold pool.

Yeah, because it's going hit the UK instead of central Europe

[Nick F]

No signs of any deep cold from the 00z EPS yet ... long road back to cold and snow for now. Need patience of a saint in the UK if you've not seen lying snow yet this winter. Because it can get to you if you spend too much time over analysing and discussing the models each day, why I try to find other things to take my mind away from the disappointment of not seeing snow from this cold spell and seeing little on the horizon. Otherwise you just get frustrated.

[AO-]

32 minutes ago, Nick F said:

None of the extended clusters showing Atlantic troughing / upper flow energy undercutting high pressure building north over Europe that would hold a Scandi high in place for a sustained enough period to bring cold air our way though, so the high would eventually collapse. My worry is the lack of low heights especially over Iberia from Atlantic troughing undercutting, as well as further east over the Mediterranean Basin from undercutting of cold air from the NE, will mean we end up with a large Scandi-Euro High of little benefit to coldies in the UK other than some surface cold perhaps.

But, we know these clusters can change, so more runs needed. But I'd feel much happier if we saw troughing extending from the Atlantic over Iberia rather than the semi-permanent Azores ridging there. Extremely dry across parts of southern and eastern Spain this winter so far, due to lack troughing extending from the Atlantic over Iberia with ridging dominating.

We can get away with cold air undercutting high pressure over Scandinavia from the NE into southern Europe to lower heights over the central Med to bring a brief cold easterly, but prefer of the Atlantic troughing undercuts too to make it more sustained.

Totally agree. But maybe first we should have some throughing over Poland/the baltics to suck the cold air South. We should not discount the history in this one. Here are two charts for day 5 of EC this morning. A southwesterly far into Russia. I dont think there will be much surface cold left in one week. That is what worries me the most atm. 

Edited January 19 by AO-

[Nick F]

Just now, AO- said:

Totally agree. But maybe first we should have some throughing over Poland/the baltics to suck the cold air South. We should not discount the history in this one. Here are two charts for dat 5 of EC g this morning. A southwesterly far into Russia. I dont think there will be much surface cold left in one week. That is what worries me the most atm. 

True, the lack of cold from antecedent mild southwesterlies pumping deep into NE Europe and NW Russia is a worry, though with the right synoptic pattern developing, it can return there from the arctic fairly quickly before the rest of northern Europe can tap into it, but without the notably low temperatures we have seen build since November over Scandinavia, will any quickly developing cold pool be too marginal by the time it reaches here? All conjecture for now, as we have to get a Scandi high to develop and get and easterly flow far enough west in the first place.

Getting all the right pieces of the jigsaw to fall into place, not least getting cold air back to the NE and E Europe, a Scandi high to extend far enough west and crucially low heights over southern Europe to stop a high to the NE collapsing south, is an uphill battle to break out of the strong +NAO pattern ensuing.

[E17boy]

10 minutes ago, AO- said:

Totally agree. But maybe first we should have some throughing over Poland/the baltics to suck the cold air South. We should not discount the history in this one. Here are two charts for day 5 of EC this morning. A southwesterly far into Russia. I dont think there will be much surface cold left in one week. That is what worries me the most atm. 

I agree that a lack of low pressure over Iberia is not ideal for high pressure to hold and bring us sustained cold. As I mentioned in my previous post earlier it’s not just about having heights over Scandinavia all the jigsaw pieces have to fall in place. My main concern is that February may well end up with a lot of high pressure but all in the wrong place for us to benefit. But too early to make judgements yet and as we know in a weeks time the setup may well look so different whether for the better  or worse who knows.

regards