Model Output Discussion 01/09/17

[Man With Beard]

3 hours ago, northwestsnow said:

12Z is basically low after low - not a chance in hell of any Atlantic retrogression with that blasted Atlantic in overdrive.

SE likely escaping most of the wet stuff but it all looks depressingly familiar .

It is a shame because i do feel the NH profile is ripe for retrogression, we just cant seem to see an end to these lows exiting the Easte seaboard, i do hope this isnt going to be a sign of things to come!

Almost not a single ECM ensemble member remotely like the GFS tonight (source: "weather.us"). By D11, one is struck by the number of strong highs centred on Moscow, influencing E Europe and disconnected from the Azores High leaving the UK delicately poised between the two highs. By D15, not many typical Atlantic lows, a great many strong highs to the W, NW, N and E - but I didn't see a single Euro High. I would expect a massive low anomaly over central Europe based upon these. In all honesty, the Atlantic has pretty much given up by D15 on these ECM ensembles. 

Given the large difference from the GFS op, I sense this situation will be a good early season test of whether the models might have a good long-term grip on the synoptics.

[East_England_Stormchaser91]

All I can say is that cold spells wherever I have seen them crop up have always been at quite short notice, with a sudden flip. How anyone can take forecasts seriously with months in advance, I'll never know. I personally didn't foresee January 2013 and then march being as snowy as what they were when we was in December 2012. It was just a continuous endless zonal train! All it took was a rise of heights midway through January and then the goods were delivered spectacularly. The models at the beginning of the month did not show it at all even at a week out. 

With the sun now approaching minimum activity, La Niña conditions and a possible E QBO, id say there is a greater risk of northern blocking. 

Edited November 4, 2017 by East_England_Stormchaser91

[LRD]

1 hour ago, SLEETY said:

Is that the same Ec46 that was going for a cold Easterly for last Dec ,and we all know how that turned out.

I don't understand why anyone takes any notice of these seasonal models,they all have proven it's still impossible to forecast seasons in advance.Waste of time and money.

Sorry but this sort of post is bonkers to me. There are loads of things, in the past, which have felt unsolveable but with persistence and patience those same problems have been solved by science. So EC46 might be wrong again. So what? One day in the not-too-distant EC46 will start getting it right and everyone will be lauding the overall accuracy of that and other longer range models. Waste of time and money? For trying to do the very good thing of expanding human knowledge and understanding? If our ancestors had taken that attitude we'd still be living in caves. It's funny but longer term climate models predicted the future under global warming and that's proving pretty accurate. I'll go with a continued waste of money (or, to put it another way, I'll go with a continued investment in science for the good and betterment of humankind and, maybe, even the future of the planet itself)

Edited November 4, 2017 by LRD

[Ravelin]

GFS pub run throwing out a Saturday night special in FI....

Edit: Sneeze and you'll miss it affair though, and no Siberian high in sight. 

Edited November 4, 2017 by Ravelin

[northwestsnow]

GFS continues with its zonal theme - quite a sharp contrast to EC.

I'm rooting GFS is barking up the wrong tree- the outlook is very +NAO driven if its right- EC on the other hand is much more amplified - as it stands it looks as if the METO are siding with the EC prognosis.

 

[bobbydog]

7 minutes ago, Ravelin said:

GFS pub run throwing out a Saturday night special in FI....

Edit: Sneeze and you'll miss it affair though, and no Siberian high in sight. 

no high? really? look at the pressure contours not the geopotential heights-

1040mb high, bang in the middle of siberia.

[LRD]

1 minute ago, bobbydog said:

no high? really? look at the pressure contours not the geopotential heights-

1040mb high, bang in the middle of siberia.

Agreed. But a high pressure cell that far away? It may as well be on Mars for all the good it will do us

 

[bluearmy]

10 minutes ago, northwestsnow said:

GFS continues with its zonal theme - quite a sharp contrast to EC.

I'm rooting GFS is barking up the wrong tree- the outlook is very +NAO driven if its right- EC on the other hand is much more amplified - as it stands it looks as if the METO are siding with the EC prognosis.

 

The gfs 18z op might be but the gefs aren't 

[bobbydog]

7 minutes ago, LRD said:

Agreed. But a high pressure cell that far away? It may as well be on Mars for all the good it will do us

 

'sigh'...... its not about direct effects. its not about getting a quick fix of snow in autumn which quite a few people seem to be looking for. its all about getting synoptics and teleconnections in place for the winter. a big strong high over there promotes blocking across the whole hemisphere, increasing our chances of getting it where it matters further down the line.

look at the bigger picture....

Edited November 4, 2017 by bobbydog

[Ravelin]

13 minutes ago, bobbydog said:

no high? really? look at the pressure contours not the geopotential heights-

1040mb high, bang in the middle of siberia.

Oh yeah, I was obviously distracted  by the pretty colours. 

[LRD]

5 minutes ago, bobbydog said:

'sigh'...... its not about direct effects. its not about getting a quick fix of snow in autumn which quite a few people seem to be looking for. its all about getting synoptics and teleconnections in place for the winter. a big strong high over there promotes blocking across the whole hemisphere, icreasing our chances of getting it where it matters firther down the line.

look at the bigger picture....

Please don't patronise me. I'm not hoping for or expecting snow in autumn and I get the bigger picture thing. But please feel free to show me the evidence that a strong siberian high in early November correlates to a cold Dec-Jan-Feb in NW Europe (NW Europe being not-far-off halfway across the globe from where that high pressure cell is)

Edited November 4, 2017 by LRD

[bobbydog]

Just now, LRD said:

Please don't patronise me. I'm not hoping or expecting snow in autumn and I get the bigger picture thing. But please feel free to show me the evidence that a strong siberian high in early November correlates to a cold Dec-Jan-Feb in NW Europe (NW Europe being virtually halfway across the globe from where that high pressure cell is)

its part of Cohens theory of the SAI. there have been scientific papers written on it. its out there if you care to look. to say "it might as well be on mars" is not really adding to the discussion and is more of a cynical snipe.

here's an example of a big siberian high in november-

[LRD]

2 minutes ago, bobbydog said:

its part of Cohens theory of the SAI. there have been scientific papers written on it. its out there if you care to look. to say "it might as well be on mars" is not really adding to the discussion and is more of a cynical snipe.

here's an example of a big siberian high in november-

That looks a very differently aligned siberian high to me. Much more ridging towards the pole. That theory you refer to... I am aware of. But we're dealing with different variables now. Well, one major variable - global warming. And we don't know how that effects all the myriad theories that are out there yet. Not cynical at all. Just using my own eyes and memory of what has gone on these past 30 years (apart from the odd blip in the 90's and during the turn of the last deacde into this one)

[Snowy L]

SAI is on thin ice after 4 consecutive winters of failure. If it does have an affect, it's an affect that is incredibly easily overridden.

[Man With Beard]

22 minutes ago, bobbydog said:

'sigh'...... its not about direct effects. its not about getting a quick fix of snow in autumn which quite a few people seem to be looking for. its all about getting synoptics and teleconnections in place for the winter. a big strong high over there promotes blocking across the whole hemisphere, increasing our chances of getting it where it matters further down the line.

look at the bigger picture....

Sorry to stray off topic for a moment but would you agree that in recent years, in our part of the world, some of the best wintry synoptics of the year have occurred in November? I remember one winter a few years ago right here where we had a few frosts in November and then none till the end of February!

I say this to emphasise that it may well be worth looking for decent synoptics in November, certainly the latter part, because we're getting used to being content on every last scrap available!

Please feel free to move to the "banter" thread if anyone feels appropriate

[bobbydog]

Just now, Man With Beard said:

Sorry to stray off topic for a moment but would you agree that in recent years, in our part of the world, some of the best wintry synoptics of the year have occurred in November? I remember one winter a few years ago right here where we had a few frosts in November and then none till the end of February!

I say this to emphasise that it may well be worth looking for decent synoptics in November, certainly the latter part, because we're getting used to being content on every last scrap available!

Please feel free to move to the "banter" thread if anyone feels appropriate

from memory, no. november 2010 is the only one that comes to mind and that was a precursor to a decent winter (well first half anyway) 

but thats not really my point. i've just been trying to point out that a strong siberian high *can* increase the chances of a colder winter in europe. i'm not suggesting the models are right at the ranges we are seeing it, or  that a big S.H. guarantees anything but considering recent winters, i see it as a positive step for the season as a whole. rather than create interest, it just seems to have created cynicism. (not from yourself). i was simply throwing it in for discussion. i wish i hadn't bothered...

[LRD]

20 minutes ago, bobbydog said:

from memory, no. november 2010 is the only one that comes to mind and that was a precursor to a decent winter (well first half anyway) 

but thats not really my point. i've just been trying to point out that a strong siberian high *can* increase the chances of a colder winter in europe. i'm not suggesting the models are right at the ranges we are seeing it, or  that a big S.H. guarantees anything but considering recent winters, i see it as a positive step for the season as a whole. rather than create interest, it just seems to have created cynicism. (not from yourself). i was simply throwing it in for discussion. i wish i hadn't bothered...

Blimey. I don't intend to be cynical. It's just a challenge and I tried to be a bit light-hearted about it. I hope you're right and it leads to something akin to 78-79 (maybe starting 7 or 8 days earlier) but I'm just not convinced that a high pressure cell appearing thousands of miles away in November gives us any greater or lesser chance of a winter of that type occurring. Especially in these warmed times. Why is that cynical? This is a public forum to debate and challenge. I don't really know what I've done wrong. I've not been insulting or condescending (although, to be honest you were to me!). I'm just trying to offer a different view and question theories that are put out there in public places and, as you say, you put something out there for discussion. Well, I'm trying to discuss it 

Edited November 5, 2017 by LRD

[bobbydog]

1 minute ago, LRD said:

Blimey. I don't intend to be cynical. It's just a challenge and I tried to be a bit light-hearted about it. I hope you're right and it leads to something akin to 78-79 (maybe starting 7 or 8 days earlier) but I'm just not convinced that a high pressure cell appearing thousands of miles away in November gives us any greater or lesser chance of a winter of that type occurring. Especially in these warmed times. Why is that cynical? This is a public forum to debate and challenge. I don't really know what I've done wrong. I've not been insulting or condescending (although, to be honest you were to me!). I'm just trying to offer a different view and question theories that are put out there in public places. 

maybe you weren't being cynical but it came across that way and there were others...

anyway, both the GFS and the ECM have shown disruption to the trop PV over several runs, including a strong siberian high (in various orientations). from what i have read, if strong enough, this high can be stubborn to shift and can persist for weeks. it affects hemispheric weather patterns, not just localised to siberia. when this happens, there has been shown to be a correlation to increased blocking elsewhere and colder winters in europe. as i said, it guarantees nothing but worth keeping an eye on in future runs. (in my humble opinion)

[knocker]

There is no indication from last night's anomalies of any significant change to the overall pattern in the next 14 days so this also applies to the previous spiel vis the general outlook for the UK. Remaining changeable, temps a little below average with the usual caveats.

There have been some tweaks however. The vortex still over N. Canada but some retrogression of the Aleutian ridge and trough NW North America. So still a flat westerly flow across the latter and into the Atlantic. Elsewhere we still have the trough associated with the vortex aligned SE >Iceland and then south to the low pressure in the eastern Mediterranean whilst at the same time interacting with the strong Russian ridge into Franz Joseph Land where there is even indications of a separate high cell. Thus a strong upper westerly flow continuing across the Atlantic tending to split around the UK as the trough to the south east and the Azores come into play. How much influence the Azores will play in this the det runs will need to decide and one would expect the inter run variations to continue vis the detail.

No obvious changes in the latter period but agreement not good so best left for the time.

Meanwhile back on the farm. To start a bit of an west/east split as a transient ridge edges in from the west so much more of the breezy, cool north westerly in the west with frequent coastal showers and quite wintry in places with sleet and snow over the high ground in Scotland. These will tend to die out throughout the day as the ridge progresses and by evening the wind will also have abated leaving the temps to start dropping quite quickly. Thus overnight an extensive air frost with temps down to -4c in the south in places and -6-8C in Scotland Monday morning. But by midday more fronts and rain have arrived in the NW as the ridge is squashed south east and milder air introduced.

The aforementioned front proceeds to track south east through Monday and Tuesday giving a wet day to all before the Azores once more ridges north east. The rest of the week, including the weekend, is dominated by the usual battle and interaction between the upstream energy tracking east and the strong Azores high pressure centred to the south west. This is best illustrated by firstly taking a snapshot of the fairly strong weest-east 500mb wind field

And then three surface analysis charts which illustrate quite well systems tracking around the high cell and impacting the north and the  N/S split which is a key feature of these patterns.

There are signs next week of the troughs/energy to the north west becoming more influential as the thermal gradient is pushed further south relegating the Azores HP more to the south west and thus the weather vis the UK becoming more generally unsettled but given the fluidity of the pattern this is getting too far ahead of ourselves although it does fit the overall pattern indicated by the anomalies.

The precipitation chart sums it up neatly

 

Edited November 5, 2017 by knocker

[knocker]

Merely out of interest the lower Strat. this morning, not a million miles from the 500mb

[knocker]

The general theme of the ecm is simlar to the gfs but it is much more amplified thus by midday Saturday it has an intense low just to the north of Scotland 974mb which would bring severer westerly gales and heavy rain to the latter and gusting 90kts not far to the north. Over the next 48 hours the low tracks into the Baltic plunging the UK into a very fresh showery north westerly and wintry conditions in Scotland, before the winds abate a little and veer northerly as the next ridge edges in

[winterof79]

Very seasonal ECM charts this morning.

[bluearmy]

The strength of the blocking to our northeast across n Asia is quite something on the extended eps. Not a new theme and the jet responds by inching further and further sw. By day 15 the mean is almosr clear of the uk on a nw/se axis.   I'm trying not to get overly interested in the background pattern but it's becoming tough to ignore what might be establishing for early winter.

[snowbunting]

Looked at both the GFS and ECM charts this morning. No surprises or massive changes from yesterdays runs. First thought is that the GFS is continuing with its cool NW ly flow hence a negative NAO trend. The high pressure in the atlantic is tempering any affect of the jetsream as is twists up and down over UK and Europe. 

The Ensembles for my area show the mild followed by colder excursions in the coming days too. 

In some respects the ECM follows that NWLy trend but with a huge area of Hugh pressure over Europe and much lower pressure over Greenland by +200hrs. 

Synoptics look promising for a mixed bag of everything the next 2 weeks and I think the models are taking time to adjust to the effect a warmer arctic.

[summer blizzard]

The day 8-10 charts of both the GFS and Euro are interesting. 

On the Euro our east Atlantic High (probably the most accurate thing to call it since it's not west enough nor over the UK) attempts to join with the Russian High and traps a low over southern and eastern Europe while the Vortex stays around Greenland (sends some chilly air west). 

Looking at the day 10 chart i think what we'd wee see afterward is a core form over northern and eastern Scandinavia (exciting) which would force a more n-s orientation of the main Greenland Trough. I suspect though that the trough would not be negatively tilted enough to undercut and hence within a day or three we'd see the high sink too much (possibly cool for the UK away from Scotland but the main cold would head to France and Spain).

The GFS however goes the opposite route in that it maintains our current pattern and pulls the east Atlantic High back west which allows a cyclonic northerly for most of Europe.