Model Output Discussion - 12th December Onward

[JRMcLeod]

Morning all,

Models continuing to show us cold fans what we don't want to see(average/mild synoptics).We shouldn't be surprised though stratosphere still anomolously cold,polar vortex still strong,+NAO,+AO.

The odd NW incursion probably the best we can expect until we see some significant change(if we ever do).

Maybe i'm not seeing or understanding the weather charts like some of the more knowledgable on here but it appears from the GFS and UKMO that we could have N/NW on or around 23rd, 26th and 27th. That too me, signifys a far larger possibility of cold polar air around Christmas and a far greater possibility of snow on the big day than what was being modelled this time last week. We seem to be forgetting that even at this range Christmas is still in FI but i am encouraged by the models from 23rd to 28th December. All we need now is timing...

Why is everyone so downbeat about a possible good model run? Am i missing something?

[SP1986]

Maybe i'm not seeing or understanding the weather charts like some of the more knowledgable on here but it appears from the GFS and UKMO that we could have N/NW on or around 23rd, 26th and 27th. That too me, signifys a far larger possibility of cold polar air around Christmas and a far greater possibility of snow on the big day than what was being modelled this time last week. We seem to be forgetting that even at this range Christmas is still in FI but i am encouraged by the models from 23rd to 28th December. All we need now is timing...

Why is everyone so downbeat about a possible good model run? Am i missing something?

Maybe i'm not seeing or understanding the weather charts like some of the more knowledgable on here but it appears from the GFS and UKMO that we could have N/NW on or around 23rd, 26th and 27th. That too me, signifys a far larger possibility of cold polar air around Christmas and a far greater possibility of snow on the big day than what was being modelled this time last week. We seem to be forgetting that even at this range Christmas is still in FI but i am encouraged by the models from 23rd to 28th December. All we need now is timing...

Why is everyone so downbeat about a possible good model run? Am i missing something?

As it stands, it'll probably be too warm at lowland areas for wintriness to occur, however again as it stands if you can find yourself a high hill, you may have a chance at recording a witnessing a white Christmas. The GFS has gone for something a little milder on the 6z, but given it's FI I might just ignore that run, and stick with the UKMO and ECM outlook.

[camiscool]

is it just me or at the end of the gfs 06z run colder air is coming off the continent towards us? surely a good sign...

[wolvesfan]

Maybe i'm not seeing or understanding the weather charts like some of the more knowledgable on here but it appears from the GFS and UKMO that we could have N/NW on or around 23rd, 26th and 27th. That too me, signifys a far larger possibility of cold polar air around Christmas and a far greater possibility of snow on the big day than what was being modelled this time last week. We seem to be forgetting that even at this range Christmas is still in FI but i am encouraged by the models from 23rd to 28th December. All we need now is timing...

Why is everyone so downbeat about a possible good model run? Am i missing something?

Hi YBY,

Its a bit like toothache for me at the moment,take a paracetemol and you get a little relief,the NW incursions being the paracetemol.My appologies for the negativity.

[Bobby]

GFS 06z ensemble mean

168

240

Flat as a pancake zonal unsettled averageness.

Azores high looks to nudge into the south for a few days before it retreats SW spreading the unsettled weather to all

[Frosty.]

Yes you and Roger lol

It's already been freezing cold as they predicted it would be but the real cold was never due until sometime in the new year so they are right.

[Summer Sun]

Merry Christmas

http://www.wetterzentrale.de/pics/Rtavn2041.png

Happy New Year

http://www.wetterzentrale.de/pics/Rtavn3721.png

[Bobby]

GEM fairly stormy at times

[beng]

except i'm not thinking that this "siberain" arctic high will sink into russia. the arctic high that is currently modelled is meandering around closer to the pole than the siberian mainland. my point is that should such a feature verify, could it not affect the tone of the zonal flow this side of the NH ? who knows, it might affect the placement of the ne canadian p/v which has been and continues to feed the zonality. hence we could see a change to the axis of the zonal flow and maybe even a change to the mean conditions in nw europe as a consequence.

Yes I'm thinking a long the same lines Nick. With an arctic high as modelled by the ECM, I'd expect a push of cold air out of the Arctic resulting in greater amplitude in the jet - i.e. a more buckled jet stream to form. At the moment though the ECM shows it pretty flat, and the GFS isn't really going for the Arctic high in such an aggressive way.

I took a look at the evolution of the Jan 85 cold spell (as it's been the in thing to quote 85 as a possible analogue for this winter), and that started with an arctic high, the jet buckled, warmer air was then driven into the arctic and that strengthened the high and helped disrupt the vortex further. Anyway - something to watch for even though it obviously may not happen.

Edited December 17, 2011 by beng

[Frosty.]

The latest ensemble mean shows high pressure to the southwest of the BI and low pressure to the north with the uk in a fairly strong westerly flow, coldest in the north but nearer average in the south, this does not mean it won't be colder at times further south but just a bit more difficult for colder incursions to penetrate southern areas. The mild 48 hours spell next week will probably be followed by shorter mild interludes but returning polar maritime air looks like being the airmass which dominates the next few weeks.

Edited December 17, 2011 by Polar_ Low

[johnholmes]

see my post, much the same as that from PL in the Met O outlooks 16-30 day thread

[A Winter's Tale]

The latest ensemble mean shows high pressure to the southwest of the BI and low pressure to the north with the uk in a fairly strong westerly flow, coldest in the north but nearer average in the south, this does not mean it won't be colder at times further south but just a bit more difficult for colder incursions to penetrate southern areas. The mild 48 hours spell next week will probably be followed by shorter mild interludes but returning polar maritime air looks like being the airmass which dominates the next few weeks.

Yeah, the models are all going for a mild spell this week. However I believe that the following period will see polar maritime air and I'm convinced that Xmas will be a cool one under NWlys rather than a mild one with SWlys showen by the models.

[Robbie Garrett]

Nice to see FI having a blocking pattern out to the area of New Foundland, it seems to form from nowhere. My question is can that Azores ridge, move over Europe? As if that high moves towards the UK/Greendland we could get flooded with -5 to -15?

I still think we will have a huge change come January.

[Frosty.]

Yeah, the models are all going for a mild spell this week. However I believe that the following period will see polar maritime air and I'm convinced that Xmas will be a cool one under NWlys rather than a mild one with SWlys showen by the models.

Yes, I can't see tropical maritime air being in control for more than a few days next week and the occasional day here and there after that, if anything, the jet will probably tilt more nw/se again and we could possibly have a colder spell between xmas and new year.

[Osbourne One-Nil]

Isn't a lot of this pure conjecture? That's not really the point of this thread.

[J10]

Latest Ski Blog with usual Synoptic patterns now out.

[karyo]

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/images3/euT2mMon.gif

The CFS is still going for an above average January for northern Europe, especially the further east you go!

February is looking average over our area and Scandinavia but still no sign of the below average temperatures in Scandinavia that GP is expecting.

I hope it starts picking up a signal for a cold February soon.

Karyo

[Nick F]

Yes I'm thinking a long the same lines Nick. With an arctic high as modelled by the ECM, I'd expect a push of cold air out of the Arctic resulting in greater amplitude in the jet - i.e. a more buckled jet stream to form. At the moment though the ECM shows it pretty flat, and the GFS isn't really going for the Arctic high in such an aggressive way.

I took a look at the evolution of the Jan 85 cold spell (as it's been the in thing to quote 85 as a possible analogue for this winter), and that started with an arctic high, the jet buckled, warmer air was then driven into the arctic and that strengthened the high and helped disrupt the vortex further. Anyway - something to watch for even though it obviously may not happen.

Can't really see much evidence of an arctic high this side of the North Pole on 00z ECM, though it does show the Polar Vortex spliting at the end of the run, with two seperate cold domes across Nern Canada and the other over NW Russia. 06z GFS elongates the polar vortex to spread right across higher latitudes from Nern Canada across Greenland to NW Russia going into FI, though a proper split would be better to allow the jet to amplify to our west.

With regards to the Jan 1985 analogue, Dec 1984 had a very strong west Russian high but also a deep vortex to the NW of the UK, the Russian high then sank SW and merged with the Azores high to form a large Euro High, but at the same time the Polar Vortex was splitting to allow a dome of cold air to sink south over Nern Russia, which then eventually moved west and southwest towards the UK during Jan 1985 giving the very cold wintry spell that month. Can't really see any great similarities yet, as there's no strong high over Wern Russia right now and the PV shows no realistic signs of splitting yet - certainly no signs of stratospheric/upper tropospheric warming to split and sink cold vortex either.

It's a brave call to see something similar to Jan 1985 in Jan 2012 to develop from the current pattern.

[johnholmes]

I'd agree Nick-more hopecasting than anything I fear, at least for the coldies.

I posted this in the Met O 16-30 day thread but its valid in here I reckon

both their 6-15 and 16-30 day outlooks, to me, seem more realistic, than the last 1 or 2 that seem to suggest a milder interlude generally.

The phrases they use seem to support the 3 500mb anomaly charts so one must assume that the oft quoted 32 day ECMWF charts (we don't see them) are following this idea. Much as I suggested earlier this morning having kept an eye on the 3 500mb charts over the past few days.

Their outlooks for both periods, in my view, are as good, in the sense of accuracy, based on the latest outputs, as we are going to get.

The synoptic models, due to the predicted 500mb flow strength, mirrored at higher levels also, will never really get hold of individual low centres or the nuances of a touch milder and a shade colder bursts of air until quite close to the event. The happenings over the past 7 days should have proved that to anyone, seasoned or new watcher on these forums.

Last Sunday the Met O Fax for T+120 (Friday) had a low of < 950mb near Newcastle, it was actually on the chart at 12z Friday at 52N09E with a centre of 965mb.Only some 500+ miles away-nothing on a hemisphereical scale but all important on the UK scale. In essence the idea of a disturbed spell was correct, just its positioning and depth not so good. That is the way it will stay UNTIL, who knows when, the major wavelength pattern around the northern hemisphere changes.

[Robbie Garrett]

http://www.cpc.ncep....s3/euT2mMon.gif

The CFS is still going for an above average January for northern Europe, especially the further east you go!

February is looking average over our area and Scandinavia but still no sign of the below average temperatures in Scandinavia that GP is expecting.

I hope it starts picking up a signal for a cold February soon.

Karyo

Interesting to note that April for once is average, and that June is above average (for once). I do wonder what Summer will bring for the Olympics let alone this Winter.

Looking at this, we've gone through our cold winter cycle then?

[ICETAB]

http://www.cpc.ncep....s3/euT2mMon.gif

The CFS is still going for an above average January for northern Europe, especially the further east you go!

February is looking average over our area and Scandinavia but still no sign of the below average temperatures in Scandinavia that GP is expecting.

I hope it starts picking up a signal for a cold February soon.

Karyo

Does anyone know how well the CFS predicted the last 3 cold winters from this sort of range?

[A Winter's Tale]

Looking at this, we've gone through our cold winter cycle then?

Most certainly not. I believe that if this month ends up being slightly below average, and the same goes for January and February then we'd have a 4th consevutive winter with Below the average temperatures.

And look at the facts and opinions of some experts, the stratosphere going to warm up and the polar vortex is going to weaken so we should see something quite a bit more colder later in the winter.

[nick sussex]

Does anyone know how well the CFS predicted the last 3 cold winters from this sort of range?

Oh the infamous CFS charts!

You'd be better off reading the tea leaves, even if they were more accurate the problem is with them that they simply reflect what the overall month ends up to be, this can mask lots of variation within that month.

Personally I think they're a load of rubbish and I said the same thing last winter even when they progged below average temps down here in sw France for January and February, what we ended up having was the complete opposite!

[I remember Atlantic 252]

icy rain, hail, sleet all coming down at once

[Andy_]

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/images3/euT2mMon.gif The CFS is still going for an above average January for northern Europe, especially the further east you go! February is looking average over our area and Scandinavia but still no sign of the below average temperatures in Scandinavia that GP is expecting. I hope it starts picking up a signal for a cold February soon. Karyo

Does this not show a cold february?

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images3/euT2mProbMon.gif