Model Output Discussions 06z 04/11/16

[Mucka]

4 minutes ago, Ali1977 said:

I agree with Mucka, I thought we may start seeing some better FI charts. I still think it's a few days too early if the possibilities the METO mentioned are correct however.

Has anyone got an image of the ECM ensembles?  I like the sound that a cluster are going for a colder setup.

The NH is by no means full of raging PV - keep an eye on the ensembles and I'm sure we will start seeing an improvement soon. The ECM has looked interesting at day10 a few times so don't discount that neither.

 

 

Here you go

Nothing frigid but cool/cold for time of year.

[Mucka]

5 minutes ago, fergieweather said:

With both long range suites (ECMWF and GloSea) still agreed on a zonal and/or cyclonic bias remaining into late November - and % likelihood of a blocked set-up emerging at some point from mid-month now until then remaining very tricky to quantify - it's unsurprising we see operational models churning-out their present fare. It'll take a while for response to predicted MJO phase (to 7/8) in next week and half to be adequately resolved, with the favoured effect of these phases still apparently in conflict to the more mobile EC/GloSea signals we see at present. Indeed, it's only at the turn of the month when we see EC and GloSea both switch to a signal indicative of a more blocked regime (EC's Monday run developing heights to our NW, whilst GloSea evolves a broad +ve MSLP signal in vicinity of the UK). So there's still great cause for uncertainty and ditto, much room for suspicion about how models are handing the route ahead. As I mentioned yesterday, the ENS members going more blocked set-up mid-late Nov remain a sizeable minority... but ones that may yet prove prophetic. 

Very informative, thanks Fergie.

I'm responding more so that people don't miss it on a new page but without putting words in your mouth, somewhat encouraging as far as the big picture goes.

Edited November 9, 2016 by Mucka

[northwestsnow]

GFS offering little to generate excitement again this evening for coldies.

A very active Atlantic over the coming week to ten days - could be some wet weather for NW Britian !

[swfc]

1 minute ago, northwestsnow said:

GFS offering little to generate excitement again this evening for coldies.

A very active Atlantic over the coming week to ten days - could be some wet weather for NW Britian !

yes that seems the way for the time being.just to note way out in fi but the whole of europe barring us and the atlantic side are under a huge area of high pressure!!!.atm tho for us unsettled at times .

[northwestsnow]

5 minutes ago, swfc said:

yes that seems the way for the time being.just to note way out in fi but the whole of europe barring us and the atlantic side are under a huge area of high pressure!!!.atm tho for us unsettled at times .

Still looking for signs of the jet digging south and pressure rises in the western Atlantic down the line, my worry is there always seems to be systems forming off the east coast of America that scupper retrogression.

Hopefully the lack of zonal winds mjo etc will help ..

Edited November 9, 2016 by northwestsnow

[January Snowstorm]

Worth a reminder that the first model to pick up on this was the gfs. At the time some said it was over progressive, atlantic biased etc.

However it looks like being the correct call even if it is just for a week or so

[Mucka]

17 minutes ago, January Snowstorm said:

Worth a reminder that the first model to pick up on this was the gfs. At the time some said it was over progressive, atlantic biased etc.

However it looks like being the correct call even if it is just for a week or so

If you mean for second half of November I think we will still need to wait and see on that.

I agree it has so far been fairly consistent with its Atlantic push in Op runs but ensembles are a mixed bag so I don't get the sense it has the pattern nailed yet.

As far as leading toward mid month GFS was very much over progressive pushing Atlantic based Westerlies into Western Russia whereas now they struggle to make it as far East as Scandinavia.

For example (and I picked this at random) a few days ago compared today's output for 14th

That is what I was talking about when I stated the output has continually overestimated the Eastward progression of Atlantic troughs and that we may well be seeing the same thing now in output which doesn't have the resolution to correctly split energy outside day 7/8 (resolution here not just referring to the lower res of FI especially but the lower res we get naturally as the uncertainties are extended and errors compounded with time)

 

Edited November 9, 2016 by Mucka

[karlos1983]

3 minutes ago, Mucka said:

If you mean for second half of November I think we will still need to wait and see on that.

I agree it has so far bein fairly consistent with its Atlantic push in Op runs but ensembles are a mixed bag so I don't get the sense it has the pattern nailed yet.

As far as leading toward mid month GFS was very much over progressive pushing Atlantic based Westerlies into Western Russia whereas now they struggle to make it as far East as Scandinavia.

For example (and I picked this at random) a few days ago compared today's output for 14th

That is what I was talking about when I stated the output has continually overestimated the Eastward progression of Atlantic troughs and that we may well be seeing the same thing now in output which doesn't have the resolution to correctly split energy outside day 7/8 (resolution here not just referring to the lower res of FI especially but the lower res we get naturally as the uncertainties are extended and errors compounded with time)

 

You could also argue that it totally underplayed how strong the PV would get, that's quite a difference  

so in summary the gfs is about as sure as we are post 4 days 

Good post though, if ever you need an example of how bad the gfs is at dealing with blocks being brushed aside by the Atlantic, that's it right there!  ^^^

[ITSY]

Very interesting update from fergie. Basically: relax for the next week guys and keep the Prozac pills away. Models still adjusting to synoptic setup and unlikely to firm up an exact signal for a week or two at least. In the mean time, take a look through the 12z GEFS suite again - some crazy Synoptics on offer in amidst them. Not as crazy as the world we live in these days, mind you...

[gottolovethisweather]

1 hour ago, Mucka said:

Here you go

Nothing frigid but cool/cold for time of year.

 

Yep, I'm confident it will trend colder from the 16/17th November (as the above indicates) with the NW flow, hopefully backing around to a polar source as we head further into FI. Before that, coldies such as myself will have to deal with a few milder days, some potentially wet but still seasonal frosts about from time to time too. Kind of what I stated last evening.

 

[Frosty.]

The Gfs 12z shows a very wet saturday and windy too with a narrow wedge of milder air slowly spreading from the west but by sunday it's drier, brighter and cooler with a few showers dotted around. Then early next week as high pressure builds in close to the south we see a more settled few days for the south and very mild air swamps the uk but it doesn't last as a polar maritime incursion spreads SE next midweek, especially for scotland with showers turning to snow on high ground. Thereafter it stays rather chilly for a few days with NWly winds but the atlantic really cranks up through low res with some vigorous depressions swinging across the uk bringing mild, wet and windy weather followed by a backwash of colder, brighter showery conditions with wintry ppn on northern hills..so a more active spell could be on the way with large temperature fluctuations from 13/14c on some days and 5/7c on others with night frosts at times.

 

 

 

 

 

 

 

Edited November 9, 2016 by Frosty.

[northwestsnow]

4 minutes ago, ITSY said:

Very interesting update from fergie. Basically: relax for the next week guys and keep the Prozac pills away. Models still adjusting to synoptic setup and unlikely to firm up an exact signal for a week or two at least. In the mean time, take a look through the 12z GEFS suite again - some crazy Synoptics on offer in amidst them. Not as crazy as the world we live in these days, mind you...

It is an interesting update from Fergie, *however* he goes on to say Glosea depicting high pressure 'close toor in the vicinity of  the UK' , thats not quite high lat blocking! Or maybe i have read it wrong ?

Edited November 9, 2016 by northwestsnow

[booferking]

When Ian Ferguson talks about response to predicted MJO phase (to 7/8) does he mean charts like the below responsed right at the end of the run??   Sorry i am still learning.

Edited November 9, 2016 by booferking

[Mucka]

4 minutes ago, northwestsnow said:

It is an interesting update from Fergie, *however* he goes on to say Glosea depicting high pressure 'close toor in the vicinity of  the UK' , thats not quite high lat blocking! Or maybe i have read it wrong ?

True but he also mentions the uncertainty with EC's suggesting blocking to the NW. I expect they are both indicative of an Atlantic block of sorts, just with different amplification which also answers booferking's post above.

The good news I take from that is that blocking is expected to take hold anywhere between last 3rd of November and early December and that the models may well be showing a more amplified pattern, especially in the Atlantic sector soon.

Then again I am always a little bias toward cold prospects so others may read something else into it.

[northwestsnow]

8 minutes ago, Mucka said:

True but he also mentions the uncertainty with EC's suggesting blocking to the NW. I expect they are both indicative of an Atlantic block of sorts, just with different amplification which also answers booferking's post above.

The good news I take from that is that blocking is expected to take hold anywhere between last 3rd of November and early December and that the models may well be showing a more amplified pattern, especially in the Atlantic sector soon.

Then again I am always a little bias toward cold prospects so others may read something else into it.

Agree with all that mucka

I have just posted the updated 30 hpa temperature graph for the Pole and it does indeed show temps dropping away now perhaps reflected in the medium term NWP product and the signal for a (hopefully) tempory building of the PV over Greenland...

[bluearmy]

If there is anything reliable in the gefs week 2 then I suggest looking ne for blocking and not nw. Whether the blocking is effective for our part of nw Europe is questionable but certainly some interesting evolutions on view and very few are zonal atlantic

 

 

[damianslaw]

Changeable outlook from todays models, a warm up as we move through the rest of the week, but only back to near average temps by the weekend, with a slow moving band of rain, could be some large totals for some which will be noticeable after such a lengthy dry period. Into next week, high pressure from the azores nosing in with a milder tropical maritime feed, so becoming mild for the time of year,but it looks a shortlived affair, as low pressure swings in from the NW and introduces increasingly colder air as the week wears on, with the northern half of the country enveloped in sub 528 dam air before the working week is out, which would no doubt increase risk of snowfall for low levels - supported by Met office forecast.

Whilst we are seeing the polar vortex set to intensify over Greenland in the coming days, there is every chance given other signals notably MJO that it may not become a significant robust feature, indeed further trough disruption quite likely with the influence of heights to our NE once again pulling the breaks on trough movement eastwards ultimately squeezing the PV from powering into gear and eventually dropping trough into central europe enabling those mid atlantic heights to ridge northwards again and perhaps join hands with heights to the NE - I'm reading between the lines of the Met Office long term forecast, and this would suggest such an evolutionary synoptical set up as we move through the latter part of November and into December.

Short term milder/average conditions for longer term colder prospects perhaps?

Edited November 9, 2016 by damianslaw

[Ali1977]

On 09/11/2016 at 18:33, bluearmy said:

If there is anything reliable in the gefs week 2 then I suggest looking ne for blocking and not nw. Whether the blocking is effective for our part of nw Europe is questionable but certainly some interesting evolutions on view and very few are zonal atlantic

 

 

Yes, some nice GEFS charts in FI with some good as Scandy blocking, Including the Control.

[daz_4]

Lot of cold air spilling south on the latest ECM. Too bad it is not directed at us 

[Tamara]

Keep watching the angular momentum budget updates!

The disconnect between ENSO base state and atmospheric circulation response, as discussed in recent posts in quite some detail, has been ramping up to something of considerable interest and significance in terms of the much anticipated return to a -AO discussed on these pages. The question, presently, is still more about timing, rather than whether it will happen at all.

Whilst the central Pacific Ocean registers weakly negative SST anomalies, the atmospheric circulation refuses to perpetuate the ENSO cycle to develop this profile and enable a coupled ocean/atmosphere response to reflect in NWP modelling.  

The 30 day SOI rolling index has continued its plunge since early October and reflects that considerable disconnect.

The Global Wind Oscillation has broken through the "psychological orbit barrier" into a low amplitude Phase 5/6/7 cycle that is representative of current El Nino atmospheric responses - and most definitely not La Nina whatever the Pacific ocean SST's suggest.  

This in response to tendency in relative angular momentum starting to ramp up as the MJO heads through the Pacific, as heads-up has provided in previous posts. Notice the orange shaded westerly wind additions heading up from the sub tropics

 

The more that this response is perpetuated by sustained additions of westerly winds across the Pacific, the less chance there is of the synoptic pattern adopting a Nina profile with anomalous ridges in the Pacific and Atlantic in the winter, and the less that net polar flow will be inclined to overspread that ridging in the northern branch from upstream - especially taking into account a recalcitrant polar vortex to augment the effects of very weak zonal flow.   

Of course the pattern ebbs and flows, but its the trend as winter wavelength changes rapidly approach, and force a coupling of the Annular Mode (AO and NAO) heading more and more to the New Year that will make the present signals relevant.

Much as happened in autumn 2009 (in the context of atmospheric responses against an ENSO state that had been weakly Nina inclined within a neutral ENSo base).. The seeds of increasing atmospheric angular momentum built up more and more amplification into the atmospheric circulation (through both the tropics and extra tropics) by adding more net westerlies tthan easterlies to the atmosphere.

Westerlies that tend to head poleward with time, and the resultant amplification eddies within an unstable troposphere and stratosphere profile create higher latitude blocking profiles

In that context although we are certainly not suggesting another winter 09/10 per se, at least we are encountering the exact same atmospheric processes as 2009 - with amplification feedbacks that lead to blocking patterns over a period of time. Remember when these charts arrived by mid December..

 

On that basis, take the MJO pulse across the Pacific as a clear signal of the atmospheric disconnext in itself (a coupled Nina state would not entertain orbit through the Pacific without dying a death in Phase 7) but more importantly the consequences - which are an amplification feedback that should be poised to take advantage of an unstable stratospheric profile through December - and further ahead to the start of the New Year. 

Accrued feedbacks that imply an entrenched -AO profile that couples with the NAO as wavelengths changes do the rest.

Take any November muck and sludge that comes and keep watching how the atmosphere jives with the stratosphere in the meantime. That's any net weather time booked for me anyway

 

[Barry Reynolds]

13 minutes ago, damianslaw said:

Changeable outlook from todays models, a warm up as we move through the rest of the week, but only back to near average temps by the weekend, with a slow moving band of rain, could be some large totals for some which will be noticeable after such a lengthy dry period. Into next week, high pressure from the azores nosing in with a milder tropical maritime feed, so becoming mild for the time of year,but it looks a shortlived affair, as low pressure swings in from the NW and introduces increasingly colder air as the week wears on, with the northern half of the country enveloped in sub 528 dam air before the working week is out, which would no doubt increase risk of snowfall for low levels - supported by Met office forecast.

Whilst we are seeing the polar vortex set to intensify over Greenland in the coming days, there is every chance given other signals notably MJO that it may not become a significant robust feature, indeed further trough disruption quite likely with the influence of heights to our NE once again pulling the breaks on trough movement eastwards ultimately squeezing the PV from powering into gear and eventually dropping trough into central europe enabling those mid atlantic heights to ridge northwards again and perhaps join hands with heights to the NE - I'm reading between the lines of the Met Office long term forecast, and this would suggest such an evolutionary synoptical set up as we move through the latter part of November and into December.

Short term milder/average conditions for longer term colder prospects perhaps?

I hardly ever post on here, but suffice to say I would be very happy with this evolution. The further into December for cold the better, November won't bring anything meaningful for us Southerners, no matter how good the synoptics.

[Summer Sun]

Good agreement till Sunday beyond this lots of scatter

[Frosty.]

Superb update as usual Tamara

The Ecm 12z shows a narrow wedge of milder air on saturday associated with a band of wet and breezy / windy weather but cooler again by sunday as a ridge of high pressure builds NE and then early next week turns much milder and also briefly more settled for the south before it becomes cooler and more unsettled from the west / northwest during the second half of next week onwards as a trough swings SE from iceland with a cold and showery wnwly flow to end the run.

[northwestsnow]

30 minutes ago, bluearmy said:

If there is anything reliable in the gefs week 2 then I suggest looking ne for blocking and not nw. Whether the blocking is effective for our part of nw Europe is questionable but certainly some interesting evolutions on view and very few are zonal atlantic

 

 

And yet ECM 12z looks very flat to me this evening Blue, can't see any prospect of blocking to the NW OR NE out to day 10 and well beyond!

Yes there is  a PM flow at day 10 but even that looks transitory, still, rather get it out the way now than in Dec/Jan etc ..

[gottolovethisweather]

1 hour ago, gottolovethisweather said:

Yep, I'm confident it will trend colder from the 16/17th November (as the above indicates) with the NW flow, hopefully backing around to a polar source as we head further into FI. Before that, coldies such as myself will have to deal with a few milder days, some potentially wet but still seasonal frosts about from time to time too. Kind of what I stated last evening.

 

 

 

 

 

 

 

 

 

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Kind of what tonight's ECM operational run is suggesting.

D8 through D10 H500 NH Profiles

 

D8 through D10 850 NH Profiles

 

 

Yes, it's in the realms of early FI being the 17th November onwards, but the same signals were broadly there yesterday evening too, and I feel it is one to watch. Revisit this post in three to five days time, and if they're still there I'd be relatively hopeful of a quick switch around from the very mild forecasted Temperatures to start next week. Even if they're dropped in subsequent runs don't panic as the 12z by 12z and/or 0z by 0z is the more relevant trend to watch!

Edited November 9, 2016 by gottolovethisweather