Model Output Discussion 1200 hrs 15/11/14

[gottolovethisweather]

well this is what the upper air pattern is probably going to look like

EC-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

NOAA

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

similarities?

All 3 show a fairly marked trough, (EC-GFS)=close to/over UK, NOAA further west, Two out of 3 a ridge from northern Europe/Russia out towards Greenland, with EC dropping that idea this morning.

So not totally clear but the trough over or west of the UK looks odds on which would suggest that the upper flow is going to come from s of west much of the time out to 15 days. Beyond that who knows.

 

Thanks John, intriguing as this is taken from my post from three days ago and summarised the BBC News 10-day forecast which is presented on each evening, in that the weather presenter suggested either of the following scenarios were likely (see below).

 

For those wanting to know what might happen in our small patch of the globe in some six to seven days (FI probably as close as t+96 right now I'd suggest) tonight's 10-dayer from the Beeb hinted at two scenarios for next weekend.

 

 

• Firstly scenario one was where the omnipresent trough remained positioned a few hundred miles due West of Ireland with a blocking Euro HP cell over central parts of Europe. End result near average Temps and some largely dry conditions around for a few.

 

• Second scenario offered up at t+168 hours plus was a trough positioned due SW of the UK, more like over the Bay of Biscay area and the HP blocking due North of the UK between Greenland and Iceland - End result a potential Northeasterly flow from Scandinavia, yes please!

 

 

Should John's analyses be near the mark, we might well see a NH pattern resolution falling between the two in a few days time. I also hear what Old Met Man is saying in his thoughts longer term too, same general idea as me.

 

So somewhere in between is where we should reside as we head into the next seven to ten days then. The 6-15 day outlook from UKMO yesterday, also upgraded the coldies hopes slightly too, with a view to looking East much later in the month. Granted, the far SW will probably get effected by some further nuisance rain and towards the far NW they could see hill snow, much later into la la land. One constant theme remains though, stubborn block to our East transferring slowly NE and a stubborn trough close to Western parts, in time drifting towards Southwestern Europe perhaps. All of this is shown in conjunction with a far from rampant Jet and a relaxed PV which is under pressure for now. This could certainly lead to a fascinating pattern in a week or so's time for sure.

Edited November 18, 2014 by gottolovethisweather

[knocker]

It's looks as if it may be quite warm this weekend. I think the analysis quite interesting. The anomaly chart has the two main players the low south of Greenland and the HP to the north est of the UK ridging south over the eastern part of the latter. But the supporting cast play a key part and they are a trough west of the UK extending south to Morocco and a ridge wedged between this and the main low.

 

So a surface low to the south and HP to the west and n. east which produces a very well defined temperature  contrast,

 

It is but transitory.

 

Charts courtesy weatherbell.com

Edited November 18, 2014 by knocker

[492]

well this is what the upper air pattern is probably going to look like

EC-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

NOAA

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

similarities?

All 3 show a fairly marked trough, (EC-GFS)=close to/over UK, NOAA further west, Two out of 3 a ridge from northern Europe/Russia out towards Greenland, with EC dropping that idea this morning.

So not totally clear but the trough over or west of the UK looks odds on which would suggest that the upper flow is going to come from s of west much of the time out to 15 days. Beyond that who knows.

Perhaps noteworthy that a closed circulation is predicted on both EC and GFS 500 mb heights charts close to N Scandivavia. This appears to be the only warm closed circulation at high latitudes in the northern hemisphere and if correct and if maintained could be the start of a decent block.  

[IDO]

Here we go on the 06z, with changes in the phasing of the lower heights to the NW and the Azores HP wedge to the SW, which negates the troughing to the SE into the  Med. So by D9 we get the repeat of the undercut drama for this week already downplayed as the ridge blocks the LP cutting SE:

 

Op  Parallel

 

So at D11 the UK just the last stop on the Atlantic conveyor belt as LP stalls against the block, and is then driven N/NE over the Sceuro ridge:

 

 Brute force from the Atlantic the block gets slowly pushed back east:

 

D12  D13 

 

The Parallel has more disruption than the op and continues its theme from this morning with low heights disrupting over the UK with the block to the east, but this time more energy going over the block so no retrogression, and back to square one by D14:

 

D10  D12: 

 

This scenario looks so much more likely, with that more organised PV, than a disrupting trough undercutting the Sceuro block. At D16 we remain in a similar pattern. We saw from last year once the pattern gets locked down it can kills weeks of the Winter. Not that this block is too bad as long as it remains a Sceuro high rather than just a mega Russian one, and we do eventually get the sliding Atlantic scenario.

 

As for this morning's GEM, it looked like one of it's regular outliers and the Mean at D10 confirms that: 

 

And as for pinning hopes on the current strat warming, the recent posts in the relevant thread are giving caution to those expectations, so in reality we need the trop to start moving in a colder direction otherwise real cold will remain out of reach.

Edited November 18, 2014 by i'm dreaming of...

[ukpaul]

And as for pinning hopes on the current strat warming, the recent posts in the relevant thread are giving caution to those expectations, so in reality we need the trop to start moving in a colder direction otherwise real cold will remain out of reach.

 

A temporarily strengthening vortex into December and a series of warmings keeping the strat on the run (as it is) has been what the knowledgeable posters on that thread have been repeating again and again. More excitable posters may not have agreed but the suggestion of late December and, especially, January cold has not changed.

[Barry12]

Here we go on the 06z, with changes in the phasing of the lower heights to the NW and the Azores HP wedge to the SW, which negates the troughing to the SE into the  Med. So by D9 we get the repeat of the undercut drama for this week already downplayed as the ridge blocks the LP cutting SE:

 

Op gfs-0-186-2.png  Parallel gfs-0-186-3.png

 

So at D11 the UK just the last stop on the Atlantic conveyor belt as LP stalls against the block, and is then driven N/NE over the Sceuro ridge:

 

gfs-0-264-3.png  Brute force from the Atlantic the block gets slowly pushed back east:

 

D12 gfs-0-288-7.png  D13 gfs-0-312-5.png

 

The Parallel has more disruption than the op and continues its theme from this morning with low heights disrupting over the UK with the block to the east, but this time more energy going over the block so no retrogression, and back to square one by D14:

 

D10 gfs-0-240-27.png  D12: gfs-0-312-6.png

 

This scenario looks so much more likely, with that more organised PV, than a disrupting trough undercutting the Sceuro block. At D16 we remain in a similar pattern. We saw from last year once the pattern gets locked down it can kills weeks of the Winter. Not that this block is too bad as long as it remains a Sceuro high rather than just a mega Russian one, and we do eventually get the sliding Atlantic scenario.

 

As for this morning's GEM, it looked like one of it's regular outliers and the Mean at D10 confirms that: gens-21-1-240-35.png

 

And as for pinning hopes on the current strat warming, the recent posts in the relevant thread are giving caution to those expectations, so in reality we need the trop to start moving in a colder direction otherwise real cold will remain out of reach.

 

No point analyzing anything over day 7, especially at the moment when we are in a high entropy period. The GFS has a clear habit of being to progressive with the Atlantic, as OldMetMan alluded too. Just last week it was meant to be an almost certainty that the Atlantic would win out against the block, but that never happened in the end. It seems some people on here just never learn. The GFS FI has showed a strong polar vortex for weeks now on most of it's runs, but it never makes it into the reliable time frame. No point at all worrying over FI charts.

[IDO]

No point analyzing anything over day 7, especially at the moment when we are in a high entropy period. The GFS has a clear habit of being to progressive with the Atlantic, as OldMetMan alluded too. Just last week it was meant to be an almost certainty that the Atlantic would win out against the block, but that never happened in the end. It seems some people on here just never learn. The GFS FI has showed a strong polar vortex for weeks now on most of it's runs, but it never makes it into the reliable time frame. No point at all worrying over FI charts.

 

There appears uncertainty in the surface flow and timings but the long wave pattern appears to have moved much closer together in the last few runs, with respective models agreeing. The CFS for December is eerily like the current and upcoming pattern other models have moved towards:

 

 

The EC32 is along these lines as is the JMA and the UK met for 16-30 days clearly favours this setup. I believe the uncertainty is coming out of the system and unless the models take a dramatic turn then the way forward in FI looks clearer.

[swilliam]

Here we go on the 06z, with changes in the phasing of the lower heights to the NW and the Azores HP wedge to the SW, which negates the troughing to the SE into the  Med. So by D9 we get the repeat of the undercut drama for this week already downplayed as the ridge blocks the LP cutting SE:

 

Op gfs-0-186-2.png  Parallel gfs-0-186-3.png

 

So at D11 the UK just the last stop on the Atlantic conveyor belt as LP stalls against the block, and is then driven N/NE over the Sceuro ridge:

 

gfs-0-264-3.png  Brute force from the Atlantic the block gets slowly pushed back east:

 

D12 gfs-0-288-7.png  D13 gfs-0-312-5.png

 

The Parallel has more disruption than the op and continues its theme from this morning with low heights disrupting over the UK with the block to the east, but this time more energy going over the block so no retrogression, and back to square one by D14:

 

D10 gfs-0-240-27.png  D12: gfs-0-312-6.png

 

This scenario looks so much more likely, with that more organised PV, than a disrupting trough undercutting the Sceuro block. At D16 we remain in a similar pattern. We saw from last year once the pattern gets locked down it can kills weeks of the Winter. Not that this block is too bad as long as it remains a Sceuro high rather than just a mega Russian one, and we do eventually get the sliding Atlantic scenario.

 

As for this morning's GEM, it looked like one of it's regular outliers and the Mean at D10 confirms that: gens-21-1-240-35.png

 

And as for pinning hopes on the current strat warming, the recent posts in the relevant thread are giving caution to those expectations, so in reality we need the trop to start moving in a colder direction otherwise real cold will remain out of reach.

Not sure why you are saying the GEM is an outlier to its mean. The Op shows a main low situated just SW of Greenland with a trough to Portugal, a Euro/Russian high with a ridge to S Scandi.

Seems quite consistent with the mean to me with the same general pattern being shown.

[492]

http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

 

Things seem to happen by stealth with an easterly feed as eyes are normally fixed on the atlantic. However at 11Z there is an upper high over Scandinavia of 564 DM. Colder air is flooding out of Russia and across Poland. The easterly feed is modelled to last a few days so it is to be expected that northern Europe will cool down somewhat this week and perhaps provide a source of cold that could with time affect the UK.   

[swfc]

Imo what we are seeing now is just standard autumn weather be it blocked to the east ete.Talk of the strat changes later this month ete are all well and good but look where we were with the mo last weekend?Hopefully a swing in the models may happen over the next few days

[Swave Snow]

Is this not the Vortex being moved over to our part of the world at 384hrs on the GEFS 

 

 

[bluearmy]

Is this not the Vortex being moved over to our part of the world at 384hrs on the GEFS 

 

 

Even if it is SS, it's at day 15 so not worth any real analysis.

There are sniffs that the daughter Canadian vortex will begin to lose strentgth week 2 but only

sniffs at the moment.

[IDO]

The problem we have, and it is a manifestation of the problem last year is the orientation of the cold uppers. I counted at least three more reloads of cold hitting the US in the next 16 days and we have to feed off the warmed out cooler uppers escaping from the NW:

 

 

As long as that placement remains in situ, all we can expect is the crumbs of cold from mainly transient PM shots.

[Barry12]

The problem we have, and it is a manifestation of the problem last year is the orientation of the cold uppers. I counted at least three more reloads of cold hitting the US in the next 16 days and we have to feed off the warmed out cooler uppers escaping from the NW:

 

gfsnh-1-6.pnggfsnh-1-192.pnggfsnh-1-384.png

 

As long as that placement remains in situ, all we can expect is the crumbs of cold from mainly transient PM shots.

 

That 384 hour chart could have freezing cold Easterly's on the 12z

 

so could the ECM day 9/10 charts, but there useless, right?

Edited November 18, 2014 by Barry95

[mushymanrob]

That 384 hour chart could have freezing cold Easterly's on the 12z

 

so could the ECM day 9/10 charts, but there useless, right?

 

im confused.... the charts you quoted that 'ido' posted dont appear to match these... what am i missing?

 

ecm @250 = day ten                        

 

what easterlies?

Edited November 18, 2014 by mushymanrob

[frosty ground]

im confused.... the charts you quoted that 'ido' posted dont appear to match these... what am i missing?

 

ecm @250 = day ten                        

Recm2402.gif Rtavn3841.gif

 

what easterlies?

The Easterlies that COULD appearer on the 12z........ I think the poster is making the point that the 384 hours chart changes all the time.

[Swave Snow]

Even if it is SS, it's at day 15 so not worth any real analysis.

There are sniffs that the daughter Canadian vortex will begin to lose strentgth week 2 but only

sniffs at the moment.

 

 

That was my point , meanwhile there seems to be fear that the Vortex is about to get stuck in its Usual place Greenland, lets hope that the 12z move everything westwards again in the near time 

[nick sussex]

The slump continues today with the ECM in particular making more of that shortwave than the others, it somehow manages some trough disruption at T192hrs and the crumb of comfort is that it still wants to take the jet se not ne.

 

Overall the output shows another stalemate, there is just about room for an upturn in cold hopes however because of the lack of agreement with the shortwave at T96hrs, its unusual to see this many solutions from the ECM at T96hrs aswell as this upstream issues which I'll come to a bit later:

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!96!pop!od!enfo!enplot!2014111800!!/

 

There is also another factor that could add more variability into the output, this is a developing low expected to cross the USA at around T168hrs, as this travels east its likely to engage the PV over Greenland, as this happens some of the low heights will get pulled nw.

 

You'll note on the GFS 06hrs run the lack of interaction between that and the PV between T168 and T192hrs, you'll see the difference the deeper low makes aswell as the more amplified pattern upstream on the ECM at that timeframe to the trough energy near the UK.

 

I do fear that this might be the start of yet another drama!

 

Overall then nothing tangible in terms of deeper cold for the UK, however whilst disagreements continue with the both the shortwave and what happens to that low upstream at T168hrs then I'm willing to hold out a sliver of hope!

Edited November 18, 2014 by nick sussex

[IDO]

That 384 hour chart could have freezing cold Easterly's on the 12z

 

so could the ECM day 9/10 charts, but there useless, right?

 

 

SW'lys and W'lys on the ECM for the UK. Closest Easterly on the ECM is maybe Switzerland!

 

And as for ECM's performance; looking at the 2m temps for the weekend we have them adjusting to 15c from 7c, that they forecast a couple of days ago! GFS has been relatively consistent with a warm day or two. ECM were indicating anomalies of 850's of +10 yet 2m temps 2c below average! Yes I am a harsh critic of ECM, it has it's faults as with all computer models, but despite this it is the best judge, with some provisos:

 

 

And I am not sure of the ECM op's frost on Sunday night for London. Though all models are struggling with timing with respect to the cold front over the weekend.

[Iceaxecrampon]

T+300

 

 

Last day in November - bang on cue for advent.

 

Winter 2014/15 finally arrives?

 

Ian

 

 

 

[IDO]

T+300

 

uksnowrisk.png

 

Last day in November - bang on cue for advent.

 

Winter 2014/15 finally arrives?

 

Ian

 

Diary for Nethermost Pike: should see some action at that altitude, if it verifies.

 

Over 60% of US snow covered. Impressive: 

 

Source: https://twitter.com/WSI_Energy

Edited November 18, 2014 by i'm dreaming of...

[nick sussex]

In relation to my previous post I've done a paintjob to explain the importance of the USA low to trough energy near the UK:

 

Heres the ECM at T168hrs:

 

 

You can see the low circled red and how the interaction will effect those low heights near the UK.

 

Next the ECM T192hrs;

 

 

Note the pulling nw of those purples from the troughing and where the energy has gone more north rather e/ne.

 

Now the GFS at T168hrs:

 

Note the weaker low, less amplified, it just runs into the troughing and the energy is pushed e/ne:

 

 

 

 

The issue we really have even with the ECM is just weak pressure rises to the ne and lot of this is to do with the earlier problems with the shortwave and how much ridging we get north before the trough gets closer.

 

However as I like to be optimistic and keep positive in the face of adversity! There is still a chance albeit small that things might improve in terms of cold.

 

So something to keep an eye on upstream in terms of that low, if we have a block further north then we might see better trough disruption near the UK at that 168 to 192hrs timeframe but its essential that we get the deeper upstream low and that this phases favourably with the PV chunk.

Edited November 18, 2014 by nick sussex

[MR EXTREMES]

 soon becomes unsettled with wet and windy weather in the later outputs of the gfs,

southern areas could escape the worst milder than average in the south but chance of colder air futher north due to lower dew points.

and more unsettled futher north and west!

 

the vortex is split but the biggest part over on the canadian side so the states have the best of it all.

most likely outcome will be a reformation of the vortex and not as far to go in and around greenland or on the canadian side of the arctic which wont do us no favours.

Edited November 18, 2014 by emotional rollercoaster

[MR EXTREMES]

although rather interesting strat chart but the vortex really ramping up will the warming do any damage i dont expect so very strong vortex developement.

Edited November 18, 2014 by emotional rollercoaster

[carinthian]

Uncertain what the next batch of charts will indicate, but the latest forecast for next week just issued by METO indicates slightly below average temperatures with increasing risk frost in the east and risk of some rain in the west. Read what you may into that, but seems blocking to the east could still hold up the Atlantic advance for a while longer anyway.

 C