Model Output Discussions 12z 01/09/2016

[northwestsnow]

UKMO looks interesting this evening-

http://old.wetterzentrale.de/pics/Rukm1201.html

http://old.wetterzentrale.de/pics/Rukm1441.html

Dry and cool to start November

[Ali1977]

5 minutes ago, northwestsnow said:

UKMO looks interesting this evening-

http://old.wetterzentrale.de/pics/Rukm1201.html

http://old.wetterzentrale.de/pics/Rukm1441.html

Dry and cool to start November

As does the GEM

[Skullzrulerz]

May I ask what happened to this cold spell at the beginning of November?

I only just managed to read the last few pages properly and I just a tad confused that there's a lot of mild/cold talk going on?

Anyway I shall await the ECM

[Mucka]

4 minutes ago, Skullzrulerz said:

May I ask what happened to this cold spell at the beginning of November?

I only just managed to read the last few pages properly and I just a tad confused that there's a lot of mild/cold talk going on?

Anyway I shall await the ECM

Not much has changed in the big picture. Anomalous warmth to end October followed by a cooling off in November.

Any possible colder spell has just been pushed back a few days after the Atlantic ridge wasn't as strong as previously modeled but the overall synoptic is much the same - still in a holding pattern.

 

[Skullzrulerz]

1 minute ago, Mucka said:

Not much has changed in the big picture. Anomalous warmth to end October followed by a cooling off in November.

Any possible colder spell has just been pushed back a few days after the Atlantic ridge wasn't as strong as previously modeled but the overall synoptic is much the same - still in a holding pattern.

 

Thank you for clearing that up  

Now my head can rest a tad in peace,now for the ecm .

Edited October 26, 2016 by Skullzrulerz

[Frosty.]

The GEFS 12z mean charts look peachy for fans of pleasant anticyclonic weather for around the next week or so before the high starts to drift west / southwest into the atlantic and weaken, we then see lowering heights from the NE coming into frame but the reliable looks about as nice as it could be at the end of october and start of november for most of the uk.

Edited October 26, 2016 by Frosty.

[Mark wheeler]

12 minutes ago, Mucka said:

Not much has changed in the big picture. Anomalous warmth to end October followed by a cooling off in November.

Any possible colder spell has just been pushed back a few days after the Atlantic ridge wasn't as strong as previously modeled but the overall synoptic is much the same - still in a holding pattern.

 

Hi mucka and thanks . As long as it is pushed back to when it real matters I don't mind eh .

Great model watching at the moment and in particular the Gfs 18z last night but I now stay level headed and don't rush to tell the family like I did do a few years ago.

 

Edited October 26, 2016 by Mark wheeler

[phil nw.]

The unusual warmth over the Arctic clearly illustrated in the 12z GFS run-this at 24hrs-the 850 +ve anomalies and expected surface temperatures

  

 

It really does bring it home when you see those red colours across the Pole.Places in the high Arctic like Svalbard still getting above freezing and now nearly into total darkness.

No wonder the main Polar Vortex is slow off the mark this year with a resultant weak and fractured Atlantic jet and abundant mid-latitude ridging.

[Mucka]

Another interesting JMA 12z for coldies.

Should see that trough develop N/central Europe and an Atlantic ridge in the extended run so probably another chilly/cold run incoming.

Edited October 26, 2016 by Mucka

[feb1991blizzard]

11 minutes ago, phil nw. said:

The unusual warmth over the Arctic clearly illustrated in the 12z GFS run-this at 24hrs-the 850 +ve anomalies and expected surface temperatures

 

 

It .

And projected to remain that way for a while yet.

 

Look at those anomalies over NE Greenland.

 

Meanwhile another cold ending to an ECM run likely with that trough near Iceland likely to dive SE. An Excellent slither of heights slicing through the polar region.

Edited October 26, 2016 by feb1991blizzard

[Frosty.]

The Ecm 12z becomes increasingly anticyclonic and warmer across southern uk during the days ahead but with overnight and morning fog, but outside the fog and in the sunshine it will feel very nice indeed, a bit cooler across the north and temperatures next week on the slide from the north and although a ridge holds through the first half of next week, pressure slowly falls thereafter as a trough swings down from the northwest over the uk. By T+240 we have a ridge looming to the west / northwest looking like it would topple SE beyond day 10 but a trough to the east and colder air spreading down across Scotland.

Edited October 26, 2016 by Frosty.

[knocker]

The ecm continues to run the eastern seaboard upper NE later this week and phasing it with the troughs emanating from the Canadian vortex so that by 12z Saturday we have the trough mid Atlantic whilst amplification has taken place to the east with the HP ridging north and the trough over eastern Europe. This resulting in some quite nifty temps over the weekend

From here the trough duly deconstructs as HP surges NE and by 12z Wednesday finds the cut off upper low west of Iberia with HP ridging in the Atlantic with troughs still to the north west. If nothing else model watching is interesting these days but I think I'll leave it there for the time.

 

Edited October 26, 2016 by knocker

[Singularity]

Those narrow 'fingers' of higher heights, which often linger on following a bout of strong blocking features, are known to give the models a particularly hard time. Especially when they become 'cut off' from the mid-latitude ridges by disrupted or southerly-tracking troughs extending or moving across to the south of them. Mid-January 2013 was a classic example of what that sort of thing can lead to, both with the models and the actual outcome. I remember Steve Murr making some big points on this. If I had the time I'd dig out some historical charts etc.

The trick is figuring out whether the jet stream will slice through or be walled off, which due to the tendency for multiple disturbances to interact in a short space of time, can be very difficult to pin down until a mere 3-5 days range.

So if those 'fingers' keep on showing up then... brace yourselves for some model swings and roundabouts!

Edited October 26, 2016 by Singularity

[knocker]

Just out of interest had a quick look at the ecm det 6-10 anomaly and the GEFS. Not bad

[NorthYorksWeather]

1 hour ago, Mucka said:

Another interesting JMA 12z for coldies.

Should see that trough develop N/central Europe and an Atlantic ridge in the extended run so probably another chilly/cold run incoming.

Synoptically it looks great, but I cant help feel even if we did get a flow from the North or East similar to the chart you have posted that the uppers will still be too high for any low lying snow this early in the season.

Of course I hope I am wrong but I feel we will need to get a really cold pool across NE Europe if we are to benefit from any early season snowfall.

The main benefit we would see is a cooler Europe so if we see any reloads as we move towards December it may be game on

[Matthew.]

The ECM 12z run is incredibly benign for the next 168 hours apart from tomorrow for north of the midlands. Just the opposite of the expected pattern for the time of year. As others has said a weak Jet stream.

[Scandinavian High.]

Let's see if we can keep this blocking in place for later part November and  in the right place to deliver. Im not looking for snow and deep cold for now let's all look at the pattern as we go deeper in to November it's looking very interesting..

[January Snowstorm]

Whilst the synoptics are most unusual I for one don't believe it will be of benefit as we move through Nov.

As Steve has said before because of ice melt and global warming are previous years data relevant....

I think the vortex will slowly gain strength through November and is just kicking off late rather than not at all.

[Matthew.]

4 minutes ago, January Snowstorm said:

Whilst the synoptics are most unusual I for one don't believe it will be of benefit as we move through Nov.

As Steve has said before because of ice melt and global warming are previous years data relevant....

I think the vortex will slowly gain strength through November and is just kicking off late rather than not at all.

Anything is possible. But the 2nd of November on the ECZm 12z still shows a unusual vortex a close watch!

[Frosty.]

Quite a benign settled looking Ecm 12z ens mean tonight with high pressure becoming the dominant feature through the coming days and very pleasant day time temps, especially in the south but nights on the cool side with mist and fog. High pressure slowly weakens next week and it gradually becomes cooler from the north but the mean makes less of the trough compared to the op and we remain under a weak ridge..nothing dramatic shown here, it looks quiet. 

[Methuselah]

6 minutes ago, Frosty. said:

Quite a benign settled looking Ecm 12z ens mean tonight with high pressure becoming the dominant feature through the coming days and very pleasant day time temps, especially in the south but nights on the cool side with mist and fog. High pressure slowly weakens next week and it gradually becomes cooler from the north but the mean makes less of the trough compared to the op and we remain under a weak ridge..nothing dramatic shown here, it looks quiet. 

'Benign' is the only word that, IMO, encapsulates the latest outputs, Frosty...The one silver-lining, bar fog, is the potential for thundersleet along North Sea coasts?

Let's face it, the North Sea is relatively warm...So, we'd need sub -11 Uppers for any meaningful snow to fall (at least near the east coast?)?

Though I did say the very same thing back in November 2010!

[Mucka]

1 hour ago, vizzy2004 said:

Synoptically it looks great, but I cant help feel even if we did get a flow from the North or East similar to the chart you have posted that the uppers will still be too high for any low lying snow this early in the season.

Of course I hope I am wrong but I feel we will need to get a really cold pool across NE Europe if we are to benefit from any early season snowfall.

The main benefit we would see is a cooler Europe so if we see any reloads as we move towards December it may be game on

I think the issue with the 850 temps is more whether we can get them cold enough for snow to fall at all to low levels so early in the season. It would require a protracted flow from NE/E to meet that requirement I expect but then if that were to happen ground temps would be sufficiently cold enough to support lying snow I would of thought, at least transient falls anyway.

All interesting speculation but purely academic for now.

Let's hope we can go from theory to practice in the coming fortnight. 

[knocker]

13 minutes ago, Mucka said:

I think the issue with the 850 temps is more whether we can get them cold enough for snow to fall at all to low levels so early in the season. It would require a protracted flow from NE/E to meet that requirement I expect but then if that were to happen ground temps would be sufficiently cold enough to support lying snow I would of thought, at least transient falls anyway.

All interesting speculation but purely academic for now.

Let's hope we can go from theory to practice in the coming fortnight. 

Not to forget 850mb temps on their own are not a great guide for snow. You still need an indication of the layer temps such as the 1000mb-700mb thickness which is better guide. This is quite a complicated subject with a number of variables. Perhaps JH would summarize? Although thinking about it it's hardly on topic in this thread

Edited October 26, 2016 by knocker

[January Snowstorm]

@ frosty

Benign is indeed the word that best sums up the outlook. 

I don't see it being pleasantly warm though.....For me early November will be cool and foggy under high pressure. Indeed it could well be a very gloomy week ahead with little sunshine imo

[johnholmes]

19 minutes ago, knocker said:

Not to forget 850mb temps on their own are not a great guide for snow. You still need an indication of the layer temps such as the 1000mb-700mb thickness which is better guide. This is quite a complicated subject with a number of variables. Perhaps JH would summarize? Although thinking about it it's hardly on topic in this thread

go to the Guides for all the detail?