Model Output Discussion - The Start Of Winter

[Barry12]

I like the ECM this evening, for a successive 12z in a row the Polar Vortex starts to move away from Greenland, the Atlantic HP get's pushed out W-SE of the UK. Also we again get low heights moving into Europe. It would be a far better position than we are in now if your looking for cold and snow.

 

Edited December 2, 2014 by Barry95

[Mucka]

ECM 10 day pretty much as expected with more significant blocking and amplification downstream than GFS though not up to GEM levels with a just hint of undercut developing.

 

 

Unfortunately upstream doesn't look to favourable on this particular run although I am still hopeful that come mid month some decent MLB will be showing up (likely Russian high growing increasingly influential) with a trough into Europe which would be a better place than where we are now though. We do still need to start seeing more amplification in the upstream pattern though with an Atlantic ridge to start showing up. The more influential high pressure to the East becomes then the more the pattern will be backed west with better prospects for height rises toward Greenland.

It looks like a long road but  things could look very different in a few days when we look at the 8 to 10 day possibilities. Virtually no chance of a cold spell setting upp by mid month but a decent chance the building blocks will be firmly in place by then with a much more blocked outlook. I'd say 2 weeks max of true zonal conditions 

Edited December 2, 2014 by Mucka

[IDO]

The Conus does get some extremes. I don't know how likely this is?

 

D10 on the ECM and the PV has been in situ over the Arctic for three days: 

 

I am not sure why but I believe a mean negative anomaly over the Pacific is not where we want to be. I am sure positive heights in this location is better going forward:

 

 

It is how much damage this more zonal phase is doing within the bigger picture and how long we are in this flow?

 

Nothing in the strat thread for a while so I am assuming nothing positive going on.

 

Latest ECM mean at 10mb: 

 

  WSI_Energy
Stratospheric cooling now forecast in the tail end of the ECMWF EPS forecast. http://t.co/2MtpwzPXpH
12/2/14, 6:14 PM

[Man With Beard]

Huge LP from the ECM at 168 hrs,could this be a game changer,or has it just gone off one one?

 

ECH1-168.gif

 

 

Looking at that chart from the closer UK view reveals a nasty looking secondary LP approaching Ireland.

 

ECU1-168.GIF

Yes, I've been fearing something like this all day, potential for a 2013/14 style storm there and now headed for the heart of the uk at D7. I fear for the wooden shed I built in the summer ...

[nick sussex]

I think its difficult to draw too many conclusions from the output in terms of detail although the overall pattern looks agreed on upto T240hrs.

 

The problem really is the uncertainty over in the USA regarding phasing or not of the polar jet with the sub tropical one, its likely from the outputs that some retrogression of the Azores  high is likely to take place and with the trend to push low heights into the Continent its unlikely to be mild.

 

We don't see as much ridging west of the Siberian high on the ECM compared to the GFS P but still pressure is likely to rise to the east, effectively this will slow down the movement east of low pressure which unfortunately means a lot of wind and rain and indeed some snow to higher elevations.

 

I think of particular concern this evening is the ECM low which looks nasty, generally though the ones to really look out for are secondary features, these small  lows can often bomb and lead to the worst problems. Hopefully the ECM will tone down this low with time.

 

For coldies although the output isn't perhaps what you want to see there are some chances for something wintry, any snowfall though is likely to be transitory in nature. But good news for the Scottish ski resorts aswell as the rest of European ones.

 

The area to look out for which really determines any cold into the UK is in the eastern USA, this is the area where you're most likely to get some phasing of those previously mentioned jets and the amplitude of any low there will determine the position of the Azores high and therefore the jet track into the UK.

 

So overall although nothing in terms of deep cold for the next ten days, it certainly should keep the UKMO on its toes and of course us as we look to the eastern USA for developments there.

[terrier]

Don't like the look of the 950mb low on the ECM tonight. Certainly don't want to see that in the run upto xmas heavy rain with flooding and damaging winds. Hope it starts been downgraded in the coming days.

[mushymanrob]

Remember the ecm's penchant for over amplification....

[Barry12]

Remember the ecm's penchant for over amplification....

 

Remember the GFS's penchant for over Atlantic....

Edited December 2, 2014 by Barry95

[West is Best]

A great name from the past. I used to follow your posts with great interest, welcome back West is Best

Thanks Good to be back

Hello wib, good to see you old chap!

I see nothing though to get excited about. But for me if it isnt an all out raging blizzard it might as well be mild. The charts have a look of winter 83-4 about them, pm northwesterly with showers, some of wet snow.

There's something massively reassuring about this mushy! Like old times

[Nouska]

With that big low on the ECM, a good time to have a look at the run in six hourly increments.

 

Courtesy of the IMO, ECM four panel - patience for loading - it is slow for me. Time scale on extreme right or mouse wheel for animation.

 

http://brunnur.vedur.is/kort/ecm0125/2014/12/02/12/ecm0125_nat_4panel1.html

[Mokidugway]

It may be over amplified ,but conditions certainly look ripe for a severe wind event in the run up to Christmas ...

[karyo]

 

 

Latest ECM mean at 10mb: 

 

  WSI_Energy

Stratospheric cooling now forecast in the tail end of the ECMWF EPS forecast. http://t.co/2MtpwzPXpH

12/2/14, 6:14 PM

That's rather worrying as we count on a stratospheric warming in December for the cold January forecast to come off!

[Frosty.]

Models don't look run of the mill to me, there is a very disturbed and rather cold pattern evolving with hardly any tropical maritime to be seen and a good deal of polar Maritimes I'm happy to say..bring on the wintry showers..I think there will be a fair amount of snow on northern hills at times this month and occasionally to lower ground.

[Frosty.]

As for the comment about strat cooling, that's just scare mongering since we haven't even felt the benefits of the much trumpeted strat warming yet, these changes downwell very slowly so the cooling strat is unlikely to impact our weather until spring if it even exists at all!

[MR EXTREMES]

could i please bank the gem 

 

 

and the ecm which both show heights fighting into the arctic circle ironic that the pretty much have the same ideas.

 

but the biggest problem is the gfs seems to be doing better than these two models but be interesting to see if the other models start to pick up on the same idea because once other models do then it could become very interesting indeed.

 

but in the shorter term the lucky lot up north will im sure be very excited or not to see some of the white stuff.

 

but as you can see london not really there just yet but still massively cooler than last winter down here so very seasonal and nice to see.

welcome back uk winter.

 

and is the winter storm heading south because theres a large scatter on and around the 11th of december could be interesting if it gets futher south still but way out consider that t96 is fi.

As for the comment about strat cooling, that's just scare mongering since we haven't even felt the benefits of the much trumpeted strat warming yet, these changes downwell very slowly so the cooling strat is unlikely to impact our weather until spring if it even exists at all!

and even so its in a weakened state anyway you can see that by looking at last winters strat massively different.

Edited December 2, 2014 by emotional rollercoaster

[karyo]

As for the comment about strat cooling, that's just scare mongering since we haven't even felt the benefits of the much trumpeted strat warming yet, these changes downwell very slowly so the cooling strat is unlikely to impact our weather until spring if it even exists at all!

I think you need to visit the stratosphere thread and do some basic reading if you think that a stratospheric event (warm or cold) in December will take till spring to evolve the atmosphere! lol

[Hocus Pocus]

Agree with top poster here sadly

Both are actually right and it generally ends in a halfway house in these situations.

[mushymanrob]

Remember the GFS's penchant for over Atlantic....

Absolutely... I agree, but in this instance its the ecm with its rather severe interpretation that has become the topic of conversation.

Its becoming apparent that theres likely to be a deep depression dominating our weather next week, the question is, assuming current predictions are correct, is how strong a feature will it be. Id suggest that with its extreme amplification tendancy that the ecm ispainiting and extreme picture and things possibly wont be quite that bad?

[Frosty.]

I think you need to visit the stratosphere thread and do some basic reading if you think that a stratospheric event (warm or cold) in December will take till spring to evolve the atmosphere! lol

I think you got the wrong end of the stick old chap, I was referring to a possible future cooling event way beyond the strat warming effects arrive. I expect several strong cold spells through the heart of this winter. As for my meteorological knowledge, I don't do too badly :-)

[MR EXTREMES]

I think you need to visit the stratosphere thread and do some basic reading if you think that a stratospheric event (warm or cold) in December will take till spring to evolve the atmosphere! lol

it didnt in 09/10 neither did it take that long in 12/13 so best keep an eye on the mjo which at the moment is very slow and until this shift then possibly we see where we head from there.

 

problem is no one really knows where the models are heading and tbh the gfs has recently been performing pretty well but thats not to say it might change its mind in coming days whether any of the models are right or wrong the actual outcome could be very different after all its the first day of winter.

 

its clear that events in the pacific have a clear impact on developements maybe might just be worth sitting back and waiting and not pinning hopes on a strat warming and in any case the current weather patterns show by the models are that of seasonal type which is a good start.

 

so much going on in the atmosphere that really is impossible to say there will or wont be a strat event what is clear its not had a good time recently so the weakened effects its showing can be changed either to support a warming event or the other way.

[Mucka]

No good news on the ECM ensemble 10 day anomaly charts I'm afraid with a more rounded shallower trough which suggests less disruption and so less likelihood of any undercut of heights to our East but it is just one more run. Hopefully we wills see better developments tomorrow.

 

[knocker]

Looking at the anomalies tonight the main point is the ECM has broken ranks. It has a more intense trough slap bang over the UK. NOAA hints at this wee bit but nowhere near that extent,  I won't go into a long winded description of the various models as it's fairly self explanatory. Suffice it to say it's the complex low pressure areas Canada-Pole-Greenland  that is causing the spat. In the extended the ECM backtracks somewhat but still pushes the HP further south. Be interesting to see where the ECM goes with this but I have my suspicions

 

Charts courtesy weatherbell

Edited December 2, 2014 by knocker

[LomondSnowstorm]

Absolutely... I agree, but in this instance its the ecm with its rather severe interpretation that has become the topic of conversation.

Its becoming apparent that theres likely to be a deep depression dominating our weather next week, the question is, assuming current predictions are correct, is how strong a feature will it be. Id suggest that with its extreme amplification tendancy that the ecm ispainiting and extreme picture and things possibly wont be quite that bad?

I must say I'm starting to get a bit concerned (having initially dismissed its appearance on yesterday's GFS(P) as being a classic GFS overdeepening  ). 

Matt Hugo just tweeted that the op wasn't an outlier and, while the ensemble mean obviously tones it down a bit relative to the op, it's still a pretty nasty looking system, vaguely reminiscent of 'Hurricane Bawbag' in December 2011:

 

Tonight's GFS(P) looked like one of the less severe solutions with its track, certainly compared to the ECM, but even with it has 50mph gusts across the central belt:

 

With the ECM op, 50mph sustained winds (>20 metres per second on the chart) right across the Irish Sea and heading towards hurricane force for many coastal parts:

From an IMBY perspective we would at least be spared another Central Belt sting jet event on that trajectory but still potentially quite a nasty storm for many, with the risk extending much further south into England on the ECM, and we'll have to hope it either tracks a bit further north or weakens significantly (ideally the latter).

 

On a lighter note, the upper profile at +120 on the ECM ens looks reasonably good for Sunday snow up this way:

Edited December 2, 2014 by LomondSnowstorm

[Frank Trough]

I think you got the wrong end of the stick old chap, I was referring to a possible future cooling event way beyond the strat warming effects arrive. I expect several strong cold spells through the heart of this winter. As for my meteorological knowledge, I don't do too badly :-)

 

So...what you're saying is you think it's going to be a "cold-hearted winter"? Totally left field, that!  

 

I must be a glass half empty sort of person because i really can't get excited by anything being shown.  What happened to my nice crisp, frosty high pressure? Certainly wintry at times on northern hills but cold, miserable rain doesn't do it for me.

 

 

 

 

that really isn't an inspiring chart, is it?

[IDO]

Horrible ECM mean from D7-10: 

 

 

 

Not a great D10 mean: 

 

GEM mean at T174:  JMA Op: 

 

UKMO FAX shows no northerly this Friday: 

 

Differences in the 8-10 day means still obvious:

 

   NOAA: 

 

More in line with GFS and that is because they only used 10% of the ECM Mean, where as they used 40% of the ECM mean on the 6-10 day mean. It appears they currently (strongly) favour the GFS solution.

Edited December 2, 2014 by i'm dreaming of...