Model Output Discussion - 23rd Jan - 12z onwards

[knocker]

Tonight's anomalies all singing from the same page and a lengthy explanation unnecessary  trop vortex N. Canada and strong HP ridging over the UK

Charts courtesy weatherbell

Edited January 31, 2015 by knocker

[MR EXTREMES]

At the end of the ECM run the 850s are in the plus 6C-8C range.

but its the only model that does so the gefs and the navgem are a dream moving forwards.

so people i dont agree with the ecm as the other models dont model the ecm output.

 

similar but they dont.

 

anyway gefs in its later chart shows a deep area of low pressure going over the top of our block droping south to our east each time this happens it amplifies the heights to edge either west or south west or north and similar showing on the nav model interesting i dont think the cold spell over is really showing on any of the models other than the +6 8c range as knockers has kindly picked out.

 

i think an attack from the north east or east is very likely but with dry cold frosty weather until the heights get pushed a little west or north west as suggest by some.

 

certainly no cause for the sun tan lotion to return by far.

[damianslaw]

The GFS inversion possibility is a throwback to quite a few years ago, does anyone remember that incidence when there was some amazing hoar frost and ice days with upper air temps well above zero.

 

That had a similar high pressure cell centred over the UK, this was early February if I remember also.I think it had to be pre 2008 as I was still living in West Sussex then.

 

The key was the high pressure cell centred bang in the middle of the UK with no wind.

 

Right I might just remember for some reason 2006 comes to mind early February, I'll see what the GFS archives make of that.

 

 

I think it was Feb 2008, we had high pressure overhead just after mid month, surface cold enabled severe frosts and beautiful sunny days with maxes around 4-5 degrees. It was the coldest spell of the winter.

[Cloud 10]

You lost me with adiabatic lol...il stick with Nick Sussex paint jobs thanks

 

High pressure needing insulin perhaps?

[johnholmes]

Cold surface air for many being predicted on the 6-10 day anomaly chart knocker showed. Anyweher with a snow cover could report some pretty low minimum overnight values.

 

Prior to that and snow showers down the eastern side coming well inland at times I would have thought and still some risk of more persistent sleet or snow due the low in the SW - these comments applying to the next 1-5 days?

 

Even just using the synoptic models, the predicted upper flow over the next few days leaves the surface high little alternative but to move as it is being shown and indeed confirmed in the 500mb anomaly chart for 6-10 days.

Edited January 31, 2015 by johnholmes

[Nouska]

The GFS at +192, with the high just settling in over the UK: cold and grey is what is being shown. That's the beginning - if it stays like that it will only get colder at the surface, irrespective of what temp is up above.

 

The cuts are for central England.

 

 

[MP-R]

I think it was Feb 2008, we had high pressure overhead just after mid month, surface cold enabled severe frosts and beautiful sunny days with maxes around 4-5 degrees. It was the coldest spell of the winter.

 

December 2007 also featured inversion weather between the 15th and 23rd with lower maxima but not-so-cold minima. Cold definitely came in the dry, anticyclonic form that winter.

[geordiekev]

At the end of the ECM run the 850s are in the plus 6C-8C range.

I'm not sure you are picking up what I meant exactly. Those warm 850s doesn't suggest anything other than cold given the synoptics.

To be fair knocker, its difficult to know what you meant as is difficult to interpret your one liner without any other explanation.

The last five weeks of model watching has showed me that t240 charts are useless atm when evolutions are popping up in the t192 range. A little bit of explanation or extrapolation would have been better imho.

Edited January 31, 2015 by geordiekev

[Cloud 10]

Must be in Thames streamer territory on the 18z at day 5?

 

[Bradowl]

Looks like Majorca will be colder and snowier than most of UK this winter going by some of those charts!

I was down in South of Spain over Christmas and I'm here now, its been completely dry apart from a brief shower today.

Local papers reckon its one of driest winters for quite a while.

That Azores high's been in control for weeks.

[Man With Beard]

OK, nothing scientific about this comment but ... can any of you really see a big High over the UK next weekend? I mean, really? Sure, that's what the models suggest but it just hasn't been that sort of winter, has it? Just as many of you couldn't see a Scandi High or Greenland high building, just because ... well, they just haven't got off the ground for goodness knows how long?

I just have this feeling we'll see a 3 day High to the west of the UK and then a trough will drop from the north again, pushing the High back home to the Azores.

[Captain Shortwave]

Slightly underwhelmed today, the north easterly seems to have been toned down a little with the trend to a quicker building of heights over the UK.Still the chance of snow showers out to Thursday, though perhaps a little longer in the south east.

GFS by day 8 has a UK high

Feels like it has been surgically drawn on

[Yarmy]

Dartboard...um...high. No real hint of retrogression, but zero Atlantic intrusion also which after last year's debacle is surely more than welcome.

[Chris K]

OK, nothing scientific about this comment but ... can any of you really see a big High over the UK next weekend? I mean, really? Sure, that's what the models suggest but it just hasn't been that sort of winter, has it? Just as many of you couldn't see a Scandi High or Greenland high building, just because ... well, they just haven't got off the ground for goodness knows how long?

I just have this feeling we'll see a 3 day High to the west of the UK and then a trough will drop from the north again, pushing the High back home to the Azores.

 

 

Well I can - There is a current trend for the Jet Stream to start moving North of the UK, rather than have the UK in a trough and it pushing South of the UK just to the West of us like below:

 

 

If you look at the overall pattern of the Jet Stream, there seems to be an eastwards progression beginning to take place. Starting before, but quite evident at T+120, with the trough sinking through Europe:

 

 

And whilst at T+180, you can see where the Jet is then in compared to now:

 

 

And the associated UK high setting in:

 

 

I do feel we are seeing the trend taking shape for the Azores High to make a push towards the UK. Question is, how far will it get? Will it topple with a potential repeat of recent patterns? Or will it set up this UK High. If a UK high does verify...what will this lead to? It might even be useful down the line?

 

By no means is what I posted above a certainty, but the possibility of this UK High is there, just not a certainty with other options still on the table.

Edited January 31, 2015 by Chris K

[weather eater]

Some interesting output from the GFS 18z and 12z could of course be complete red herrings but very encouraging.

[knocker]

To be fair knocker, its difficult to know what you meant as is difficult to interpret your one liner without any other explanation.

The last five weeks of model watching has showed me that t240 charts are useless atm when evolutions are popping up in the t192 range. A little bit of explanation or extrapolation would have been better imho.

 

Regarding T240 the anomaly charts are all supporting HP, in general if not in detail, so there is a good chance of this materialising given other support as well. I didn't elaborate because I thought it was fairly obvious particularly as there were other posts on the subject of inversions.

[Pembroke Dangler]

Slightly underwhelmed today, the north easterly seems to have been toned down a little with the trend to a quicker building of heights over the UK.Still the chance of snow showers out to Thursday, though perhaps a little longer in the south east.

GFS by day 8 has a UK high

Feels like it has been surgically drawn on

That's quite an impressive chart for any time of the year, not because of the cold or snow but just for the shear Synoptics given the year we've had in meteorology terms! Almost feels like we deserve a big huge area of high pressure slap bang on top of us!

[knocker]

An example when the 1000-500 thickness would be very deceptive as it wouldn't pick up the cold layer as the 1000- 850mb would.

Chart weatherbell

Edited January 31, 2015 by knocker

[SMU]

Jan 31 2015--- A possible 2010 redux............

 

 

A noticeable step change across some of the models tonight. ( UKMO 144 & NAVGEM 12z 144-180)

 

These + Some of the ensembles are picking up on the pattern becoming significantly amplified at day 8, if the inflection point is far enough west the scoop of cold air out of the pole could be VERY significant- we are talking sub -20c air dropping South out of Greenland-

The modification would bring that upwards to -14c as it hits Scotland.

 

I saw this scenario develop in 2010 where the ECM was WAYYY to far east & the GFS licked it. ( rare )

 

heres the best case scenario.

http://www.meteociel.fr/modeles/gefs_cartes.php?code=19&ech=6&carte=1&mode=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=1&ech=6&carte=1&mode=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=2&ech=192&carte=1&mode=0

 

 

remember this Chart

http://modeles.meteociel.fr/modeles/reana/2010/archivesnh-2010-12-15-0-0.png look at the break point - over Northern Greenland-

 

ECM 7 days before.

00z way east

http://www.meteociel.fr/modeles/ecmwf.php?jour=8&mois=12&annee=2010&heure=0&archive=1&mode=1&ech=72&map=1&type=0

12z closer

http://www.meteociel.fr/modeles/ecmwf.php?jour=8&mois=12&annee=2010&heure=12&archive=1&mode=1&ech=72&map=1&type=0 big correction west

the next day the ECM totally failed

5 days before

http://www.meteociel.fr/modeles/ecmwf.php?jour=10&mois=12&annee=2010&heure=12&archive=1&mode=1&ech=72&map=1&type=0

 

finally nailed at day 5

 

There isn't quite as much blocking towards Greenland this time- but we could tap the cold.

 

Look at the UKMO 144 break point.

http://www.meteociel.fr/ukmo/runs/2015013112/UN144-21.GIF?31-18  nicely west-   needs more inflection.

 

 

Interested in significant upgrades overnight.........

S

 

Chart of the day

http://modeles.meteociel.fr/modeles/gens/runs/2015013118/gensnh-7-1-312.png

Edited January 31, 2015 by Steve Murr

[Severe Siberian icy blast]

Jan 31 2015--- A possible 2010 redux............

 

 

A noticeable step change across some of the models tonight. ( UKMO 144 & NAVGEM 12z 144-180)

 

These + Some of the ensembles are picking up on the pattern becoming significantly amplified at day 8, if the inflection point is far enough west the scoop of cold air out of the pole could be VERY significant- we are talking sub -20c air dropping South out of Greenland-

The modification would bring that upwards to -14c as it hits Scotland.

 

I saw this scenario develop in 2010 where the ECM was WAYYY to far east & the GFS licked it. ( rare )

 

heres the best case scenario.

http://www.meteociel.fr/modeles/gefs_cartes.php?code=19&ech=6&carte=1&mode=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=1&ech=6&carte=1&mode=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=2&ech=192&carte=1&mode=0

 

 

remember this Chart

http://modeles.meteociel.fr/modeles/reana/2010/archivesnh-2010-12-15-0-0.png look at the break point - over Northern Greenland-

 

ECM 7 days before.

00z way east

http://www.meteociel.fr/modeles/ecmwf.php?jour=8&mois=12&annee=2010&heure=0&archive=1&mode=1&ech=72&map=1&type=0

12z closer

http://www.meteociel.fr/modeles/ecmwf.php?jour=8&mois=12&annee=2010&heure=12&archive=1&mode=1&ech=72&map=1&type=0 big correction west

the next day the ECM totally failed

5 days before

http://www.meteociel.fr/modeles/ecmwf.php?jour=10&mois=12&annee=2010&heure=12&archive=1&mode=1&ech=72&map=1&type=0

 

finally nailed at day 5

 

There isn't quite as much blocking towards Greenland this time- but we could tap the cold.

 

Look at the UKMO 144 break point.

http://www.meteociel.fr/ukmo/runs/2015013112/UN144-21.GIF?31-18  nicely west-   needs more inflection.

 

 

Interested in significant upgrades overnight.........

S

 

Chart of the day

http://modeles.meteociel.fr/modeles/gens/runs/2015013118/gensnh-7-1-312.png

Steve the difference is the vortex up above

. The votes back then was prime for amplification but the projected pattern in 10 days time is for a much developed vortex ? Not sayin it will happen like this but simply highlighting the difference

[TEITS]

I would love Steve M to be right but sadly I don't think he will be.

 

The 18Z ensembles continue to be a mess.

 

However the signficant fact is out of all the very cold ensemble members we have seen over these past 24hrs, none of these have actually appeared on the operational runs. Now this combined with the ECM outputs suggests to me the outlook of HP either centred over the UK or just to the W is the most likely outcome.

 

 

Sorry wrong link!

Edited February 1, 2015 by TEITS

[londonblizzard]

Unfortunately a weaker set of GEFS ensembles on the 18Z regarding the split around next weekend. More members going for the mild, high pressure over the UK option. Also a milder mean from then on too. Still pleeenty of time for change though. It's more likely to change than to not change given the time frame, let's hope that change is for the better

[Timmytour]

I would love Steve M to be right but sadly I don't think he will be.

 

The 18Z ensembles continue to be a mess.

 

However the signficant fact is out of all the very cold ensemble members we have seen over these past 24hrs, none of these have actually appeared on the operational runs. Now this combined with the ECM outputs suggests to me the outlook of HP either centred over the UK or just to the W is the most likely outcome.

 

 

Sorry wrong link!

I'm not reading Steve M as setting himself up to be either right or wrong, rather just highlighting a potential evolution.

It would be nice if it did come off, but I'm sure he's not actually saying it will happen, just that it could

[Trom]

The point is he's given a possible scenario and backed it with charts.  If people can't suggest evolutions of runs then this thread would be pointless.  I don't see any claims of likelihood but just possible evolutions of the current synoptics.

 

 

There have been a few posts recently that have stressed the importance of this site as a platform for learning which I whole heartedly agree with.  I have no issue with someone pointing to a possible direction we could take down the line, especially when the post is in the realms of FI anyway.  We all look to the next period of volatility for a take and the ensembles suggest that's next weekend.

 

I've seen a lot of indicators that the MJO may be begin from this point forward (5th Feb).  I'd be interested in posters views of the significance of this for the Atlantic going forward.

Edited February 1, 2015 by Paul
Removed quote as the post was removed.

[knocker]

Just a general comment on the morning's GFS run

 

After the middle of this week the weather for the UK is basically dominated by HP out to T384.