Model Output Discussion 29th December - Into mid-Winter.

[jvenge]

29 minutes ago, Seasonality said:

For my central European location ECM has introduced a much colder regime again this week. If I take the 00z output as read then it'll be -14 on Friday morning, just a couple of days ago I was looking at mildish weather for that period. Now the 06z operational is making a move that has been hinted at in the last couple of sets of ensembles and extending the freezing regime into the first days of February, there'll more ice fishing on the River Vistula if it comes off. Looks even colder in Moldova. Very dry and high pressure dominated, so lots of old dirty snow and sheet ice hanging around.

*edit. Just to emphasise that a fair few have commented that the cold over Europe will be much harder to shift than predicted initially. Looking like a good call so far to me.

Yep, 2-3 days ago +9 was showed for me and then all of a sudden, that went to a -13. 

Only taking anything within 7 days as a reasonable chance and then looking at within 5 days for it to be considered likely.

[Seasonality]

4 minutes ago, jvenge said:

Yep, 2-3 days ago +9 was showed for me and then all of a sudden, that went to a -13. 

Only taking anything within 7 days as a reasonable chance and then looking at within 5 days for it to be considered likely.

Caution as always when looking at a single GFS run and anything past a week out, but I just had a glance at the GEFS out to 240, no point going out any further, and it is generally a cold picture at the surface yet again for much of Europe. But when the models are flipping like they have been in recent days it is just for fun.

[chris55]

22 minutes ago, Ali1977 said:

Can this block really hold on then move North?  The ENS currently coming out at 168 definately show it holding on, with a lower pressure in and around Germany which could help (Steve Murrs Navgem pic very similar).  Is something afoot, if so why and can we move towards a Scandy block much quicker than an SSW would potentially do it.  

Infact we have a few ENS now showing a proper batle ground snow event by the 30th of Jan - this is interesting.  Can't post pictures but if someone could show this  that would be good.  Looking at the ENS at 174 there are 4/5 battleground events  P10/5/18 are good examples.

Yes Ali that's what we want to see!!

that second lobe of high pressure moving out of Siberia is held up by the low to the south which allows the split Atlantic flow to push throw to the south rather than just disrupting up against the euro high, every thing sharper 

[jvenge]

2 minutes ago, Seasonality said:

Caution as always when looking at a single GFS run and anything past a week out, but I just had a glance at the GEFS out to 240, no point going out any further, and it is generally a cold picture at the surface yet again for much of Europe. But when the models are flipping like they have been in recent days it is just for fun.

I think something changed the last few days. Some more experienced posters will need to say what, as the GEFS were showing a lot of milder options out into FI. I remember saying that I was skeptical such a large area, literally all of Europe, could be at the warm anomaly it was. Will be interesting to look at the EPS 46 output in the morning to see if the medium/longer term is changed buy the sub 15 day output.

 

[nick sussex]

One feature  that has popped up in recent days is yet another low pressure hanging around over the nw Med and this is what we want to see.

Even if that cold pool doesn't effect the UK I still think we're going to have to be looking towards the east/ne in the medium term as theres little chance of proper Greenland blocking.

In past situations where you get a big drop in the zonal winds you can see the outputs slowly adding westwards corrections to the outputs, we need to see this trend accelerated, it might be a bridge too far to get that cold pool sufficiently west but we might see more trough disruption later and so a chance things could improve from a cold standpoint.

[Ice Day]

1 hour ago, Ali1977 said:

Can this block really hold on then move North?  The ENS currently coming out at 168 definately show it holding on, with a lower pressure in and around Germany which could help (Steve Murrs Navgem pic very similar).  Is something afoot, if so why and can we move towards a Scandy block much quicker than an SSW would potentially do it.  

Infact we have a few ENS now showing a proper batle ground snow event by the 30th of Jan - this is interesting.  Can't post pictures but if someone could show this  that would be good.  Looking at the ENS at 174 there are 4/5 battleground events  P10/5/18 are good examples.

Here you go Ali, Pertubations 5, 10 and 18. There's a few others that have a similar evolution but don't quite deliver for the UK.

It will be interesting to watch the countdown to the 30th January on tonight's and tomorrows runs, is this a growing trend or will it be gone by the 0z's?

 

 

Edited January 23, 2017 by Ice Day

[beefy201]

I just get the feeling it will never happen this winter for the UK . A very mild and wet start to February for most of UK apart from the SE which might hang on to the cold dank weather a bit longer yet. 

[Jimmyh]

31 minutes ago, beefy201 said:

I just get the feeling it will never happen this winter for the UK . A very mild and wet start to February for most of UK apart from the SE which might hang on to the cold dank weather a bit longer yet. 

Interesting to see that the mild core is being pushed back and back here. One thing I want take up here is Cold Dank weather??? I am a coldie and I love snow and hate mild train southwesterlies, this winter certainly hasn't been dank in any way shape or form. Sub Zero nights 7+ on the trot and wet settled snow to boot. This I feel is a far more difficult winter to forecast in anyway shape or form. Look at the form horse blocked weather, 2 named storms, compare this to last year or 13/14 and 14/15 horrendous.

I do get alarmed at peoples responses to Dank boring winters. 2 camps either you are a mildy or a cold one. This has been a fascinating winter for me personally as trying to understand what is happening in between the mild rampers. Thankfully certain members try to help and get us as much info as possible. They know who they are keep up the great charts for enthusiast like myself.

Where is Frosty????

  

[Guest]

JANUARY 2017 MODEL OUTPUT COMPARED TO JANUARY 1972 - SOME REMARKABLE SIMILARITIES

Just to prove it, I can do shorter posts (never one-liners though!). If you go back to the "live updates" in my post on page 297, you'll see that today's European max temps were slightly down on yesterday's.

Using analogue charts from the archives can serve as a useful additional guide to exploring various possible model evolutions during periods of greater uncertainty than usual. This is providing that they are not taken too literally and are not quoted in the Daily Express the next day! I am not going to look at any historic or epic cold spells for this very reason. I do have a very good memory of many interesting past weather events from the late 1950s to the mid 1990s. From middle age onwards, I find that one's more recent memory is not so clear. I feel that January 1972 has some interesting similarities to this January. That Winter from late November 1971 until mid/late January 1972 also had a lot of MLB with "Euro-slugs" predominating. It was mostly dry and predominantly mild with only a couple of short lived colder incursions. There were several periods in December and again in early January where the HP edged a little further north (I'm sure that the ECM would have produced their D10 charts showing an easterly flow!) but the Jet Stream pushed through to the north and flattened any amplification. Time and again cold pools moved into eastern and south-eastern Europe but failed to move right over us. There were also several brief more zonal periods but just as in this Winter, the anomalous HP quickly reasserted itself close to or just to the south of us. In mid-January it looked like a continental flow would really take hold but the Jet Stream and the Atlantic decided that this was a good time to move up a couple of gears and pushed the promising pattern back into eastern Europe. Then we saw one of the fastest changes to the synoptic pattern that I have ever seen. A deep LP to our north-west developed a vicious little secondary LP which pushed right through the centre of the UK.  It looked like we were in for a prolonged stormy period but something remarkable happened. The secondary LP stopped in its tracks over the eastern North Sea and the Benelux countries. It filled at any incredible pace. The eastern European HP rapidly built a strong ridge north-westwards and within 24 hours we had a strong Scandi HP and a bitter easterly flow. Over less than 48 hours the maximum temperatures in southern England fell from +12c to -2c! We then had about a week of sub-zero temperatures with a strong wind chill in the biting south-easterlies. It was very dry, so practically no snow apart from a few showers down the east coast and over the south-east.

                         

Meteoceil archive link, for those interested in the whole 1971-2 Winter (or any other dates):  http://www.meteociel.fr/modeles/archives/archives.php?day=29&month=1&hour=0&year=1972&map=0&region=&mode=2&type=ncep

1971/72 was also a weak La Nina Winter trending towards neutral in the Spring. A quick check seems to indicate that 1971/72 did not have an SSW event (although only tentative records go back to 1971). The comparisons stop there. Arctic Sea ice was far more extensive back then. All that I am trying to demonstrate is what can happen with a similar set up and broad pattern in a predominantly mild and blocked Winter. There are very few examples as most blocked Winters are considerably colder. 

 

Edited January 23, 2017 by Guest

[bradymk]

I feel like something is starting to brew in the models. Some pretty big changes occurring in the mid range looking at 12z GFS. 

[ArHu3]

1 minute ago, bradythemole said:

I feel like something is starting to brew in the models. Some pretty big changes occurring in the mid range looking at 12z GFS. 

big changes but I think changes we don't want to see, the cold has retreated even more to the east

[Spurry]

2 hours ago, Jimmyh said:

Interesting to see that the mild core is being pushed back and back here. One thing I want take up here is Cold Dank weather??? I am a coldie and I love snow and hate mild train southwesterlies, this winter certainly hasn't been dank in any way shape or form. Sub Zero nights 7+ on the trot and wet settled snow to boot. This I feel is a far more difficult winter to forecast in anyway shape or form. Look at the form horse blocked weather, 2 named storms, compare this to last year or 13/14 and 14/15 horrendous.

I do get alarmed at peoples responses to Dank boring winters. 2 camps either you are a mildy or a cold one. This has been a fascinating winter for me personally as trying to understand what is happening in between the mild rampers. Thankfully certain members try to help and get us as much info as possible. They know who they are keep up the great charts for enthusiast like myself.

Where is Frosty????

  

Depends on where you live ,I would suggest that It has been dank here in NW England , and certainly not exceptionally cold .

[bradymk]

When comparing today's 12z chart for Saturday versus the 12z run 2 days ago, you can see the big difference. If these changes keep occurring, something of interest may certainly pop up sooner than we might have expected.

Massive difference in the western Mediterranean for just two days. 

Edited January 23, 2017 by bradythemole

[Ali1977]

Poor 12z really, quite boring watching models from 150 onwards as nothing really happens. Hopefully the ENS have more interest, prob a good time to have a few days or more away, and hopefully something better will start showing up for Feb!!

[IDO]

1 hour ago, bradythemole said:

When comparing today's 12z chart for Saturday versus the 12z run 2 days ago, you can see the big difference. If these changes keep occurring, something of interest may certainly pop up sooner than we might have expected.

Massive difference in the western Mediterranean for just two days. 

Although there are differences, that is expected as a D7 GFS chart will always over play the Atlantic; but otherwise the longwave pattern is very much along the same line; an EPO ridge, euro surface high, PV actively moving to our north and Azores high. To me that is offering little potential and even if the euro high is delayed further, we know from the last couple of months this is a winter killer for most of the UK viz snow. Both charts are pretty bad and TBH the one from two days ago at least moves us along rather than waste more time in this current pattern (unless of course snow is not your thing).

By D16 not much has changed from what I was showing on Saturday, and why we would want this pattern to be maintained is puzzling:

Hopefully a quick response to the strat warming will show up by the end of the week and then we can ditch the upcoming pattern and anything will be an improvement on the next 16 day forecast. Otherwise there is not much to be interested in for at least three weeks IMO (extrapolating from the D16 chart, caveats aside).

Also the ensembles are more interested in sustaining the euro high or the Azores helping a UK high so confidence in the op and means are lower than usual until we see the direction of travel the ens are making?

Edited January 23, 2017 by IDO

[Allseasons-Si]

This is what i want to see in future runs with more trough disruption heading SE,check pert 16 out at 150hrs

Edited January 23, 2017 by Allseasons-si

[mb018538]

I think we all know that's about as likely as Donald Trump not being a bigot.

Pretty poor 12z UKMO and GFS....looks like a week or more of turbulence coming up. Buckle yourselves in folks.

[Seasonality]

2 minutes ago, Allseasons-si said:

This is what i want to see in future runs,check pert 16 out at 150hrs

Pure filth, what was @Ali1977 just saying about looking for any interest in the ensembles?

[Paul_1978]

3 minutes ago, mb018538 said:

I think we all know that's about as likely as Donald Trump not being a bigot.

Pretty poor 12z UKMO and GFS....looks like a week or more of turbulence coming up. Buckle yourselves in folks.

Agreed. I feel it's too short notice for any big changes now, and it's all eyes on the SSW situation for our next cold shot!

[bluearmy]

1 hour ago, bradythemole said:

When comparing today's 12z chart for Saturday versus the 12z run 2 days ago, you can see the big difference. If these changes keep occurring, something of interest may certainly pop up sooner than we might have expected.

Massive difference in the western Mediterranean for just two days. 

The ecm op has led the way over the ens in general by dropping w European heights  (or at least not raising them ) in the 7/10 day timeframe 

[Allseasons-Si]

11 minutes ago, mb018538 said:

I think we all know that's about as likely as Donald Trump not being a bigot.

Pretty poor 12z UKMO and GFS....looks like a week or more of turbulence coming up. Buckle yourselves in folks.

Not impossible though is it!

9 minutes ago, Seasonality said:

Pure filth, what was @Ali1977 just saying about looking for any interest in the ensembles?

yes pure filth but i like it and there is plenty of interest at 144 hrs to keep the optimism alive

Edit:now the interest has ramped up come 240 hrs on the ens.

Edited January 23, 2017 by Allseasons-si

[The PIT]

GFS showing that the Atlantic is struggling to break through. The ukmo has it piling straight through. UKMO is the 2nd best model so you'll have to go with that over the GFS.

[Jimmyh]

1 hour ago, Spurry said:

Depends on where you live ,I would suggest that It has been dank here in NW England , and certainly not exceptionally cold .

agreed @Spurry but to say holding onto the Dank weather for someone in South East London whom has had more sub zero frosts than I can remember on a trot, better run I think than 2010 actually

[chris55]

P16 really does deliver the goods!

A combination of the building Russian high and the nice shortwave over Ukraine, developing a much more east west flow, coupled with the Atlantic being forced south makes for some really nice viewing.

Probably the most perfect synoptic evolution we could get out of the current pattern (for cold) and is really not very likely but not totally impossible. And all within 7 days, not asking much eh.....P16 vs the world ha.

 

Also it looks to be a retrograde pattern, with the east affecting the west.

Edited January 23, 2017 by chris55

[Singularity]

6 minutes ago, The PIT said:

GFS showing that the Atlantic is struggling to break through. The ukmo has it piling straight through. UKMO is the 2nd best model so you'll have to go with that over the GFS.

UKMO is also the more inconsistent on this occasion, in fact the difference to its 00z run at just 4-5 days range is so extreme that I'm tempted to turn my back on it in shame for several days (but of course I won't because you never know what it might do next!).

There do seem to be some odd fluctuations taking place with how fast and far the Atlantic trough surges east across the Atlantic, and it seems not to take a lot of slowing down to create enough of a gap between it and the systems near Scandinavia to allow ridges to edge NW from Europe and attempt to lock the jet in on a southerly trajectory that fires straight into the Med. with dramatic results. Still the outside chance but notable that it exists at all within just 5-7 days range.