Model output discussion - 1st December onwards

[feb1991blizzard]

2 minutes ago, chionomaniac said:

Remember that separate clustering may show flattened Euro ridges and Scandi ridges and somewhere in between in separate clusters. We just don't know.

Yes very true, maybe I'm a tad greedy!

[knocker]

19 minutes ago, inghams85 said:

Would you say there are small steps towards a Scandinavian over European block knocks?

No idea ingham. With all that's going on in the Pacific that's a bit above my pay grade. All I can say is that the last EC32 update had more or less this scenario on the 1st of Jan and three days later the ridge had gone. But that was Monday.

Edited December 16, 2015 by knocker

[Nouska]

Couple of points on previous posts....

The temp anomaly, in centigrade over the US at a similar timeframe as the ECM one in Fahrenheit.  

looks to be getting close to a 20c anomaly on there. 

The black hole situation in the anomaly charts on Meteociel - Sylvain reads here so hopefully he can have a look at a solution. Good time to look at the ensemble tabular format for Geopotential heights over northern Scandinavia.

Finally ECM 360 Z500 mean - it's too limited to get the full picture and will be muted by all the different solutions at that distance.

 

[Mucka]

My contribution, tonight's 18z FI developing.

 

[feb1991blizzard]

Pub run having a stonking right go at building a big ridge at T288.

[knocker]

7 minutes ago, feb1991blizzard said:

As long as its not very positively tilted and as long as its sharp and running quite high up latitude wise Nick, its still a good building block, this isn't going to be the killer blow to the vortex but as long as it weakens it and leaves it ripe to further attacks in the new year.....

The trough is roughly neutral, mid Atlantic with no great southerly extension. Quit weak in fact.

[feb1991blizzard]

2 minutes ago, knocker said:

The trough is roughly neutral, mid Atlantic with no great southerly extension. Quit weak in fact.

Yes I meant the ridge quite high up, neutrally aligned  trough sounds ok to me.

Edited December 16, 2015 by feb1991blizzard

[inghams85]

20 minutes ago, nick sussex said:

I think Knockers gone to his woodshed! lol The movement of the high will be dictated by how the troughing to the west aligns and if theres a negative tilt to it. Negative running nw/se, neutral north/south positive ne/sw.  You want to see a long elongated trough neg tilted digging as far se as possible this will help the high further north and nw.

 

13 minutes ago, knocker said:

No idea ingham. With all that's going on in the Pacific that's a bit above my pay grade. All I can say is that the last EC32 update had more or less this scenario on the 1st of Jan and three days later the ridge had gone. But that was Monday.

Thanks chaps. It's fascinating watching the building blocks elaborated so well by GP

[nick sussex]

OMG call a COBRA meeting, frost and ice warning!

Both the GFS and ECM have that deep low in the west Atlantic around T240hrs, so I think this is now looking like the first chance to rid ourselves of this vile horrible mild muck.

That needs to hold back and help drive some WAA north, that low still looks a bit too rounded for my liking so it might take two chances.

Hopefully the MJO can work its magic and help us get over the finishing line.

[joggs]

Would the big high over ne states have a similar effect on the vortex as a sceuro high.Or any high in the northern hemisphere?

[Cheshire Freeze]

To whoever wanted the latest GLOSEA modelling.....

 

Classic -NAO (at least getting towards-higher heights to S and SW than I would like) with troughing to the east. Ignore temperature plots when it comes to UK LRF modelling- unless you happen to live on a continental land mass they appear to be pretty useless.

 

Upper air temps at or slightly below average but again don't read too much into these....

 

 

Aside from that, brilliant 18z GFS FI with a nice scandi high and further attacks of the vortex. We'd eventually go very cold from there.....

Edited December 17, 2015 by CreweCold

[joggs]

Thanks Cc

[feb1991blizzard]

3 minutes ago, CreweCold said:

To whoever wanted the latest GLOSEA modelling.....

 

Classic -NAO with troughing to the east. Ignore temperature plots when it comes to UK LRF modelling- unless you happen to live on a continental land mass they appear to be pretty useless.

 

Upper air temps at or slightly below average but again don't read too much into these....

 

 

Aside from that, brilliant 18z GFS FI with a nice scandi high and further attacks of the vortex. We'd eventually go very cold from there.....

Cripes I only looked at the H5 - they didn't look as good, that chart looks an absolute ripper!!

 

Only one slight problem is they are still high to the south.

Edited December 16, 2015 by feb1991blizzard

[feb1991blizzard]

Jan Feb Mar SLP anomaly ties in with Ian's tweet as well.

https://twitter.com/fergieweather/status/676892266221469696

Edited December 16, 2015 by feb1991blizzard

[Cheshire Freeze]

5 minutes ago, feb1991blizzard said:

Cripes I only looked at the H5 - they didn't look as good, that chart looks an absolute ripper!!

 

Only one slight problem is they are still high to the south.

Could be less of a problem Feb through March. That's as strong a Greenland high anomaly you're likely to see on that model...

 

[carinthian]

Ok, lets look at the far reaches of the latest ECM model at 240 hours. How can we get a Scandi high from this postion. Presently I would calculate 30% post 240 hours. Ideally, I would like to see that Low circulation in mid-Atlantic a bit further west and south with a more pronounced trough to align between The Azores and Iberia. This would help to ridge high pressure northwards and allow colder Arctic feed path on its Eastern flank to sink into Europe. That's the position we have to aspire to turn cold and drier. Obviously more runs will determine the outcome whether a NE block develops but signs are encouraging albeit slow at the moment but could form rapidly with the right circumstances in place.

 C

[Captain Shortwave]

At this present time I cannot see a proper wintry spell developing before the New Year, again as I stated a day or so ago whilst we get well above average heights acros a good part of Europe, what we fail to see is below average heights over southern Europe.

GEFs anomalies

Again the suggestion is a Euro/Scandi ridge with either a very mild SW flow or a chillier surface flow off the continent. Other solutions look unlikely at this juncture but of course one must off underestimate the ramifications of a strong mid-latitude ridge in future modelling as we head into January.

But at this point the search for a clear signal to develop a cold easterly flow remains a little out of sight.

[IDO]

Ignoring the crowd pleasing pub run, which is always advisable, the GEFS are currently trending towards another Euro High for this Kelvin wave. Too early to be confident but the mean is showing this:

D11>>    D13>>   D14>>

That should bring another plume of very mild uppers from the S/SW and seal December in the record books. Although there are above normal heights in Scandi, the core HP cell is an Euro one rather than Scandi based.

CFS weeks 2-4 keep that Euro high in the perfect place to draw in further bouts of warm uppers, a near perfect Summer synoptic: 

D13 GEM and similar set up but fewer members going with higher latitude HP cell:

Really this is much of the same at the moment, the repeating Euro high bringing above average temps to our region with the jet perilously close to the areas in the NW that have already been prone this winter to floods. More runs needed...

 

[Cheshire Freeze]

32 minutes ago, IDO said:

Ignoring the crowd pleasing pub run, which is always advisable, the GEFS are currently trending towards another Euro High for this Kelvin wave. Too early to be confident but the mean is showing this:

D11>>    D13>>   D14>>

That should bring another plume of very mild uppers from the S/SW and seal December in the record books. Although there are above normal heights in Scandi, the core HP cell is an Euro one rather than Scandi based.

CFS weeks 2-4 keep that Euro high in the perfect place to draw in further bouts of warm uppers, a near perfect Summer synoptic: 

D13 GEM and similar set up but fewer members going with higher latitude HP cell:

Really this is much of the same at the moment, the repeating Euro high bringing above average temps to our region with the jet perilously close to the areas in the NW that have already been prone this winter to floods. More runs needed...

 

Au contraire my friend au contraire. I think I'm starting to see signs of a shift in emphasis with both the latter stages of the GFS and to a slightly lesser extent the ECM in recent runs. Tell tale signs of the jet becoming more sinuous and ridges protruding to higher latitudes than they have for some time. Ensemble means at 10+ days out- USELESS.

0z GFS more amplified into early -mid FI than it has been for a long time. Atlantic and Siberian ridging evident here

 

 

Also, when did the CFS become so savvy on here? Once upon a time it was pretty savagely slated  Now it's seemingly the pinnacle of bold predictions up to 4 weeks into the future.

Edited December 17, 2015 by CreweCold

[IDO]

6 minutes ago, CreweCold said:

Au contraire my friend au contraire. I think I'm starting to see signs of a shift in emphasis with both the latter stages of the GFS and to a slightly lesser extent the ECM in recent runs. Tell tale signs of the jet becoming more sinuous and ridges protruding to higher latitudes than they have for some time. Ensemble means at 10+ days out- USELESS.

Early days of a different variable so the models always tend to go loopy for a few days till they get a grip on the changes to the Atlantic NH profile. That is why I tend to go with the mean as at D11 onwards it its verification is usually +50% plus compared to the op run, more so when entropy is as high as it is showing after D11. The question is does the wave have enough to dislodge a strong ENSO/+AO locked in pattern? I need some more convincing.

[Cheshire Freeze]

14 minutes ago, IDO said:

Early days of a different variable so the models always tend to go loopy for a few days till they get a grip on the changes to the Atlantic NH profile. That is why I tend to go with the mean as at D11 onwards it its verification is usually +50% plus compared to the op run, more so when entropy is as high as it is showing after D11. The question is does the wave have enough to dislodge a strong ENSO/+AO locked in pattern? I need some more convincing.

To be honest I've seen enough today from the GLOSEA to be reasonably assured a major pattern change is on the way some time into the new year. It has replicated a Greenland high/Scandi trough scenario for the past 3 months- SOLID in its assertions. Put this together with the common consensus of a warming strat into Jan and I think that we can be as confident as we possibly can be that what we're beginning to see in the extended NWP are the foundations to an AO flip. 

Obviously, this may be ultimately proven false but with what is infront of me it's the only way I can call it at present if I was asked to make an educated judgement of post Christmas conditions.

Reading between the lines of GPs posts (he can't say much on here) suggests a pretty similar tale. Interestingly he said that we may get warmer yet before any pattern change- likely that we may find ourselves under some impressive WAA just post Christmas....hinted at by the GEFS. All par for the course though,.

Edited December 17, 2015 by CreweCold

[knocker]

Nothing much to note on this morning's gfs except the next ten days will see periods of rain and strong winds with temps remaining above average but slipping nearer average towards the end particularly in Scotland. A couple of charts that epitomize the ten days.

[knocker]

The GEFS anomalies this morning contain no major surprises. The 6-10 has the vortex N.Canada with associated trough running south of Iceland. The Euro HP is ridging through eastern Europe north to the south of the Baltic Sea.  Ergo the UK still in the SW flow so still periods of wet and windy weather, more inclined to the north and still the temps above average.

The 11.15 sees the pattern retrogress with the trough now south of Greenland and the HP ridging NE through France/Germany to N. Sweden. So essentially the flow remains in the SW quadrant but with the UK more under the influence of the HP the weather more settled but temps still above average.

Edited December 17, 2015 by knocker

[Ravelin]

Fairly good agreement between this mornings GFS and ECM out to t192.

 

After that though they diverge, possibly due to that low shown developing in the Atlantic on the ECM? By t240 they bear little resemblance. 

Who, if either, is calling it correctly? 

[Smiler1709]

even if the euro/Scandi materialises and we do get a flow from a more continental feed, it won't be much cooler than what we have currently, Europe is having a horribly mild winter also so we really are gonna have to have a big pattern change overall to get the northern part of Europe cooler/colder. 

Really need to lose those heights over the Med. looking bleak at the moment for any sustained cold. We can only hope things change come January.