Model Output Discussion

[SMU]

Im fairly pleased with both the 12z & more especially the parallel run, take for instance the location of the 0c isotherm, well south of the UK & ridging into Southern greenland that looks to get off-Its going to be a cold week- not epic cold or on a par with 81, but a good start to winter in terms of NH perspective....

I think the latter stages of the weekmay play into the hands of the Scottish if things allign just slightly better...

T156 Parallel-

http://91.121.94.83/modeles/gfsp/run/gfsnh-0-156.png?12

Awaiting UKMO to update

Parallel Chart of the Day >>> Jan 85-

http://91.121.94.83/modeles/gfsp/run/gfsnh-0-360.png?6

& A word on this ^^ you dont need a huge greenland block to generate perfect snow conditions for the UK, ideally a zone of transient higher pressure in a sausage shape across the NW atlantic like above serves to filter the very cold in from the continent whilst keeping the atlantic ona southern track alligned to the English Channel-

THis is my Perfect Winters Chart-^^

steve

Edited November 29, 2009 by Steve Murr

[weather eater]

Another interesting run from the GFS and another evolution, it does appear to run out of steam as we get into FI and ends up a bit like the 06z, if in doubt default to rather zonal, PM zonal mind. This run wouldnt have to change much to get some cold air over us (see Parallel run as pointed out by Steve). Question is will we get the heights and how will the stalling low behave.

Edited November 29, 2009 by weather eater

[cooling climate]

That parallel run would be a cracking start to winter if it verified. Another two of three

days and we could well be seeing a lot more runs like this.

[Frosty.]

That parallel run would be a cracking start to winter if it verified. Another two of three

days and we could well be seeing a lot more runs like this.

Is the parallel run supposed to be better, if so

[cyclonic happiness]

FI has been so all over the place in the past week or so, that I think we can expect something very unusual over the next couple of week, and hopefully, cold.

The hight rises midway in the run are about as far as I dare to look, but it all seem encouraging.

[chionomaniac]

The GWO analogue charts that GP has put up previously for phases 4/5 are still the form horses for the start of winter. They showed considerable deep troughing over the UK with a very much weakened/ disturbed polar vortex but not necessarily great blocking.

The MJO is within touching distance of phase 7 and the joys that that would bring.

I believe the models are grasping phase 7 (Scandi height rises) as a natural progression from phase 6, but with a MJO forecast suggested to return back to phases 4/5, we can see how this can slip through the fingers, with a return to the current cooler conditions and UK trough as per GP's thoughts.

I don't believe that it takes too much of a shift of tropical convection patterns to move that trough southwards otherwise we are back to phase 5 and more of this:

c

Edited November 29, 2009 by chionomaniac

[karyo]

The 12Z UKMO keeps us cool all week but at 144 hours there is a lot of energy in the Atlantic! http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=144&carte=1021

Quite a scatter in the gefs ensembles from the 6th of December with the operational on the colder side http://www.netweather.tv/index.cgi?action=ensviewer;sess=

Chiono, I think the MJO will reach phase 7 but as a weak event. The MJO forecasts have consistently underestimated its progress eastwards. I remember a few weeks ago it was not expected to exceed Phase 3!

Karyo

Edited November 29, 2009 by karyo

[The Eagle]

THis is my Perfect Winters Chart-^^

steve

Synoptically it's stunning. Very little meaningful cold air on the Continent for the forseeable future which makes me think it's too early for this setup good and all as it looks. The orientation of the setup seems not quite right to get the really cold air to dig down into Mainland Europe. It's all acedemic that far out but Id prefer it late December or January.

[Iceberg]

I don't buy the multi split PV deep zones shown by the alternative GFS, it attempeted 5 leaf clover pattern with a HP centre would be fantastic but has as much chance as a 4 channel CAT 5 shown by GFDL.

I know its meant to replace GFS but I really don't rate it to be honest and it might well be put back from it's December take over. PLEASE NOAA...!

Edited November 29, 2009 by Iceberg

[weather eater]

I don't buy the multi split PV deep zones shown by the alternative GFS, it attempeted 5 leaf clover pattern with a HP centre would be fantastic but has as much chance as a 4 channel CAT 5 shown by GFDL.

I know its meant to replace GFS but I really don't rate it to be honest and it might well be put back from it's December take over. PLEASE NOAA...!

I doubt its any worse than the GFS model we have now.

[Backtrack]

I severely doubt it, there's meant to be cloud moving in during the night. I reckon -1C for absolute minimum around here, maybe -2C towards Chester. Could be wrong I reckon -1.3 or -1.4C will be the lowest we'll record.

Are you sure? BBC goes for minus 3c with clear mostly all of the night, even the GFS is showing minus 2 for around here like you say.

Do you definatley think we will get below freezing because normally it will get to 2c and stop falling around here!

Maximums of 3c for tuesday look probable.

[cooling climate]

ECM at t144 could get very interesting with a massive pna ridge 1050 showing on the n/hemisphere

meteociel charts.

[Yeti]

Synoptically it's stunning. Very little meaningful cold air on the Continent for the forseeable future which makes me think it's too early for this setup good and all as it looks. The orientation of the setup seems not quite right to get the really cold air to dig down into Mainland Europe. It's all acedemic that far out but Id prefer it late December or January.

I know what you mean, but to be fair if that chart came off the LP would undercut the block and drag in CAA from the NE. There is still plenty of cold pooling about at this time of year at more northern latitudes - it's just a question of pulling it further into Eurasia, which tends to happen later on. Hence synoptics generally need to be "better" at this time of year to create a shot of equal cold to one in February.

Having said that, it seems a real long shot atm in terms of getting anything decent. The 12z is quite nice pattern-wise, but it hasn't really been supported by the Euros, especially regarding the mid-Atlantic block. The Atlantic looks much stronger on the Euros, and the GFS' evolution (i.e. block retrogressing NE) would not be possible without a weaker Atlantic. Still the odd-one-out, rather than the trendsetter, for me atm.

[SMU]

ECM at t144 could get very interesting with a massive pna ridge 1050 showing on the n/hemisphere

meteociel charts.

yep- but its more than that a HUGE Omega block setting up-

In terms of the UK- instead of a sinuous jet flowing west to East we get a small arm going around Greenland, hence the shear on the atlantic system & the undercutting shortwaves-

For all the pessimism we are not that far from a great set up-

S

YES-impressive-- almopst the sausage transient special t'up north-

S

Edited November 29, 2009 by Steve Murr

[weather eater]

yep- but its more than that a HUGE Omega block setting up-

In terms of the UK- instead of a sinuous jet flowing west to East we get a small arm going around Greenland, hence the shear on the atlantic system & the undercutting shortwaves-

For all the pessimism we are not that far from a great set up-

S

I'd rather assume the worse and not get my hopes up at this stage, it all needs to get through the crucial 144hr 168hr mark, coupled with the fact that these things have a habit of promising much and delivering little. its only so many times you can get your fingers burnt.

[cooling climate]

ECM at t216 looks excellent.

Well on meteociel anyway.

[swfc]

yep- but its more than that a HUGE Omega block setting up-

In terms of the UK- instead of a sinuous jet flowing west to East we get a small arm going around Greenland, hence the shear on the atlantic system & the undercutting shortwaves-

For all the pessimism we are not that far from a great set up-

S

YES-impressive-- almopst the sausage transient special t'up north-

S

Hi steve ,as you say not a bad run run but not quite the push from the north east towards the end of the run and quite a strong area of low pressure in the atlantic.Would you see that low going south east and the high moving westwards.Excuse my limited knowledge

[snowmadchrisuk]

ECM at t144 could get very interesting with a massive pna ridge 1050 showing on the n/hemisphere

meteociel charts.

1050 ?? Where ECM +144 below :

[kold weather]

ECM is ok but not really going to mean much difference to the type of conditions now, lower pressure but practical weather will be nearly identical. Flow becoming more zonal again and strengthening at 240hrs, though of course thats very far out, a westerly would soon be on its way with that chart...but still an improvement on the last ECM run even though the Atlantic is just as active.

[Iceberg]

Unfortunately the upper flow of the ECM is very similar to the 00Z, (some good consistence from ECM).

The mega pacific buckle, which allows a very temperary jet diversion down into southern spain/Africa, allowing for a slight easterly.

This upstream buckle then quickly resets due to the fluidity of the northern hemisphere flows atm and we end up back to the typical jet through the UK routine.

[Alex95]

What exactly is the difference between the GFS run and the GFS parallel run over on Meteociel? Is either of these runs more accurate?

[cooling climate]

72h

96h

120h

144h

168h

192h

216h

240h

function changeImage(link,image) { linklink='http://www.meteociel.fr/modeles/' + link; document.getElementById('image').src = image }

Edited November 29, 2009 by cooling climate

[nick sussex]

It's been quite some time since we saw this type of output, has the PNA over in the USA and Canada ever been this positive since we've all become model anoraks? The gfs operational run really looks out on its own here and goes against the euros aswell as the gem and i think is another gfs special to meet the shredder!

If we look at the general pattern it looks reasonable to go with the azores high displaced, low heights remain over central europe, the jet tracking more nw/se towards western europe with weak height rises to the ne, the problem is a few hundred miles either way in terms of output means a huge difference with the polar front very close to the uk.

Very hard to say how this will turn out, fingers crossed for a happy snowy outcome for the UK, here in sw France it looks wet and cool but positively very snowy for the Pyrenees. :smiliz19:

Edited November 29, 2009 by nick sussex

[Optimus Prime]

What exactly is the difference between the GFS run and the GFS parallel run over on Meteociel? Is either of these runs more accurate?

Depends what you regard as accurate because any chart out to that range is probably useless.

[Frosty.]

yep- but its more than that a HUGE Omega block setting up-

In terms of the UK- instead of a sinuous jet flowing west to East we get a small arm going around Greenland, hence the shear on the atlantic system & the undercutting shortwaves-

For all the pessimism we are not that far from a great set up-

S

YES-impressive-- almopst the sausage transient special t'up north-

S

The ECM 12z is as good as I dared to hope for with the PFJ digging as far south as southern spain across to central Italy, undercutting lp, cold continental SE'ly winds backing E'ly, low pressure all week and beyond giving a chance of wintry ppn and probably excellent news for the scottish ski industry and northern hills/mountains generally, even at the end of the run at T+240 hours I wonder if we are looking at a slider low with the nw / se jet tilt in place :smiliz19:

Edited November 29, 2009 by Frosty039