Model Output Discussion 18th Nov.2013-12z onwards.

[Tim Bland]

So the ECM slowly backtracked to the other models 😒

[Matty M]

Quite poor runs this morning for a serious cold outbreak.

 

The EC Det backs up yesterday evenings mean in latter parts with general indication of high slowly sinking and westerlies back in the Atlantic,

 

Not looking as good in the long run as it did a few days ago.

So the ECM slowly backtracked to the other models

I would not say a middle ground has been met as happens most times. But the 'cannon fodder' GFS has performed just as well as the other 2 majors on this.

[nick sussex]

No shortwave heading se this morning from the ECM and because of this the high is forced south as too much energy spills over the top. Part of the problem here is the toning down of that low near the east coast of the USA, this was more amplified on last nights runs and as it phased with that low further north we saw the energy drive north at the same time that shortwave headed se.

Overall it looks like high pressure over the UK, in terms of temps that really depends on how much cloud gets pulled into that, if its clear there could be quite an inversion, with frost and fog. It's not the worst pattern to have as its been pretty wet for the UK. But if you're looking to get the sledge out anytime soon its not great, we need to see either a signal for retogression or a big northwards shift in the high and thats difficult to achieve without the initial undercut.

Even then in these situations alot of the upper cold often heads into mainland Europe, we'll have to see what happens after this holding pattern.

Ironically this morning the GFS does drop some energy south ahead of that amplified low but too much energy spills east across Greenland but its certainly better in terms of potential than the ECM!

I should add that until the models agree on events in the eastern USA then theres still room for yet more changes!

Edited November 19, 2013 by nick sussex

[EML Network]

Well it's no surprise to me, the charts have been showing the UK slap bang underneath High pressure for a week or so.

 

So yes the UK (surprise surprise) is likely to find itself stuck in a no mans land with all the action taking place around it , some signs that Eastern Europe and probably Central Europe too are finally going to see Winter start (all be it very late for them).

 

The good news is that there's absolutely no sign of a return to a mobile pattern, what seems more likely than not is for a series of high pressure systems to meander north to South over the UK, so a - NAO looks to be the order of the day for a while, I just hope the cards stack themselves in favor of us tapping into a decent a more potent cold spell at some point. 

 

All the time were in this pattern...we stand a chance and it's about as good a position as any to be in going into December

 

[shaky]

Gota give it to the gfs it was never forecasting an easterly or a greenland high and it seems to be right . surprisingly its performed better than the ecm!!

[IDO]

Lesson: So back to ignoring those T240 ECM runs.

The GFS Op has been consistent with a MLB close to the UK; just variances on that theme.

Finally ECM has started to edge towards this possibility, yesterday and more so today.

GFS is now trending its mean towards a sinking HP: T240:

Looking like the first cold snap just (winter) seasonal; a 2-3 day toppler followed by a cool high. Shame, but it could have been worse; looking forward to some dry cold mornings.

[Bristawl Si]

 

Well it's no surprise to me, the charts have been showing the UK slap bang underneath High pressure for a week or so

 That's exactly what i've been thinking (observing).Bar a few runs, away from that scenario, it's been the form horse for days now.

[radiohead]

Gota give it to the gfs it was never forecasting an easterly or a greenland high and it seems to be right . surprisingly its performed better than the ecm!!

The ECM and the GFS are the two best models for their range. ECM is usually the best, but not always, so not too surprising when the GFS wins some "rounds". This isnt the end of the changing and evolving of the pattern, lets see what the 12Z's throw up later.

[Severe Siberian icy blast]

The ECM and the GFS are the two best models for their range. ECM is usually the best, but not always, so not too surprising when the GFS wins some "rounds". This isnt the end of the changing and evolving of the pattern, lets see what the 12Z's throw up later.

Agreed but let this be a lesson to ones who believed the ECM every time. The gfs has been so fickle though . And the ECM had been more consistent with weather from the northeast/east. But the gfs stuck to its guns and we have to give credit where it's due.The way forward this winter to avoid severe disappointment is this:When the models pick up on a cold period of weather in fi , have in your mind that now matter how cold and snowy the models look , always think that it will get watered down 100% by the time it's gets to the day. Don't believe noting until it's inside t72 , and if looks to good to be true , then it probably is. As good as some are on hear , a lot have a cold bias(including myself) and we throw all our eggs in the baskets of those that sell us a freeze up . Gfs has led the way regarding the positioning of the high next week , and the ECM has been done .Don't no whether things will change , I hope so . But cold crispy sunny days is nice all the same. But to save disappointment like Iv said , expect downgrades when the models show a cold spell, the likely hood is , the uppers will be tempered, the snow will be replaced by rain, and a 2week cold spell will become a cold snap.

[Timmytour]

I wouldn't say the GFS has performed well, but the fact that it has been so inconsistent from run to run was an indication that there was nothing cut and dried about what was coming and a reason to view the more consistent models with a pinch of salt

[alexisj9]

Hmm, I still think Melissa is the key here, 18z models had her going to Greenland, now she seem to be heading in the Portugal Spain direction. Is that path a sure thing now?

 

If not expect more changes.

[shedhead]

Agreed but let this be a lesson to ones who believed the ECM every time. The gfs has been so fickle though . And the ECM had been more consistent with weather from the northeast/east. But the gfs stuck to its guns and we have to give credit where it's due.The way forward this winter to avoid severe disappointment is this:When the models pick up on a cold period of weather in fi , have in your mind that now matter how cold and snowy the models look , always think that it will get watered down 100% by the time it's gets to the day. Don't believe noting until it's inside t72 , and if looks to good to be true , then it probably is.As good as some are on hear , a lot have a cold bias(including myself) and we throw all our eggs in the baskets of those that sell us a freeze up .Gfs has led the way regarding the positioning of the high next week , and the ECM has been done .Don't no whether things will change , I hope so . But cold crispy sunny days is nice all the same.But to save disappointment like Iv said , expect downgrades when the models show a cold spell, the likely hood is , the uppers will be tempered, the snow will be replaced by rain, and a 2week cold spell will become a cold snap.

Not so sure it's all about supporting the ECM persay, as ever its more about supporting the model that shows the coldest outcome....and in summer of course the warmest.  GFS gets a tremendous amount of stick in here at times from certain quarters, never more so than when it's showing lowering heights to the north. However imo it's nowhere near as bad as portrayed and it's more than a tad ironic the many of it's main detractors sit there watching every chart churn out on a regular basis.  There are undoubtedly lessons to be learnt here regarding the last week of model watching, but will they be learnt and will anything change when the next cold plunge shows up at T+384hrs?? Somehow I doubt it.

Edited November 19, 2013 by shedhead

[Frosty.]

Ecm 00z looks pretty cold to me, cold and blocked with widespread frosts and freezing fog. The Gfs 00z also looks rather cold and anticyclonic with attempted wintry reloads from the north...it could be a lot worse, at least there is no sign of sw'ly mush and the positions of the high (s) will keep chopping & changing which could unlock a very cold blast.

[radiohead]

Hmm, I still think Melissa is the key here, 18z models had her going to Greenland, now she seem to be heading in the Portugal Spain direction. Is that path a sure thing now?If not expect more changes.

The GFS sends ex-Melissa towards Iceland but the ECM phases her with another area of low pressure and which takes a very different track. We'll see what the NHC think in their update in a couple of hours.

[snowangel32]

So the gfs was the correct model I didn't see that coming it seems to handle pattern changes the best in recent times it shows us eye candy then takes it away, lets hope the new ecm update today improves it because it got badly wrong his time.

[snowwonder]

This may get deleted but I have watched this model output forum for so many years as I find reading the charts very hard. I appreciate the knowledge of so many of you. For someone who struggles from one chart to another it is still a roller-coaster every winter and I prob speak for others who read this forum just for pleasure. 

FWIW its pretty true perhaps to not  trust a model until <72hrs and then the disappointment wont be as bad.

Look at today, defrosting car and it started to lightly snow only for a min or so but first taste of winter today.

Cheers

SW

[MP-R]

Well the concensus still seems to be a quite lengthy anticyclonic spell of weather coming up. All models seem to agree on that, just with differing duration into FI. So despite a rather apologetic cold spell in terms of wintriness today-Thursday, frost and fog will most likely become a feature later in the week and beyond. 

[Smiler1709]

Just because the models are sitting the high slap bang over us does not mean it can't migrate north east and stick us in the freezer, we have got to stop taking each model run as certainty. I think we are perfectly set up ready to go into December, let's get Europe cold while keeping us seasonal, then hopefully the models can't send that pressure north/north east and stick us in the freezer for Christmas.

[snowking]

We almost seem to have gone full circle on this one, with the initial idea of the high toppling in to the UK (but propped up by lower Iberian heights) seemingly the favourite this morning. As has already been pointed out this morning with the upstream pattern still variable overall still time for some changes, but if we remember back to last winter we saw some similar issues with the modelling of the vortices of the polar vortex and how much energy they would leave in various places.

We have seen similar today, with the stratospheric ECMWF charts showing us the split upper vortex at day 8:

We that split all the way up to the 20mb level too by day 9:

The trouble is though that by day 10:

The weaker of the two vortices moves just that little bit too close to Greenland (at least according to yesterdays 12z ECMWF that is).

This is also shown well by the vorticity charts:

This is a slightly different situation to last year though in as much as we were seeing such charts as this last year following an SSW. This year we are looking at such charts showing up whilst we still have a developing vortex as we head towards the winter season. Whilst it still stands to reason that the above charts show bags of potential in the medium range with a few subtle tweaks (the most notable one being the movement of the weaker vortex away from Greenland), we are not likely to get as many shots at this pulling off anything substantially colder at this time without further disruption to the vortex.

Still we haven't even reached winter yet and to put a more positive slant on things the early signs of this disruption to the vortex, at a time when the composite years (accounting for wQBO, ENSO Neutral and something approaching solar maximum conditions in terms of the Labitzke et al. Solar Flux definition) suggested we would struggle to see such developments can only be seen as a good thing.

Patience

SK

Edited November 19, 2013 by snowking

[Chris K]

Not sure how people can say certain models are 'right' or 'wrong' when the forecasted charts haven't even occured yet?

 

People have been saying a mid-lattitude high has been more likely than any Northern blocking and this continues to show in this mornings outputs. If the High does end up slapped over the UK, it doesn't look mild as clear skies will be more likely with it centered over us. Details of cloud cover (if any) won't be certain until nearer the time though.

 

There are hints of the high eventually sinking, but for now, I don't see any 'zonal' weather in sight apart from the rather inconsistent FI range. Cold, settled, frosty with some late autumn sunshine looks likely for now. No snowmageddon that many desire I know, but I'm personally pleased with the outlook after the recent 'wetter' phase of weather we have had.

 

And you never know the High might end up migrating northwards at some point instead of sinking...but that is something to look out for as we progress towards late November.

[Frosty.]

There has been a change in the Ecm 00z ensemble mean since the 12z last night, by the weekend the high is further east which means the showery N'ly for the east has gone, it's been shunted much further to the east, however, the ecm mean is cold and anticyclonic with light winds, widespread sharp frosts and an increasing risk of freezing fog. Eventually the high begins to drift southeast but even by T+240 hours it's still covering the whole of the uk but beyond that, the atlantic is knocking on the door to the northwest of the BI but it could mean a spell of cold zonality with the jet axis wnw / ese or better still, nw / se.......but that's into early december and a lot will change, definate eastward shift in the ecm pattern though.

[Yarmy]

Just because the models are sitting the high slap bang over us does not mean it can't migrate north east and stick us in the freezer, we have got to stop taking each model run as certainty. I think we are perfectly set up ready to go into December, let's get Europe cold while keeping us seasonal, then hopefully the models can't send that pressure north/north east and stick us in the freezer for Christmas.

 

Absolutely, just hope it's not cloudy. Currently, the best model at T216 and beyond is...

 

 

Now, not having pored over charts for years I have to respect what the more experienced members say (and justify with examples) about certain models being too progressive, or not handling split energy over Greenland correctly or whatever, or the stats masking the regional skill variations. However the models are constantly being upgraded and if a certain model is regionally bad somewhere it is necessarily better somewhere else, and all of the NH affects our weather here in some way down the line. So I'm going to continue watching the GFS while taking into account the observations of those who have witnessed the synoptic patterns many times before.

[MKN]

Everyone slightly downbeat about long term prospects but there's a good chance a fair few of us will see snow in the early hours of Thursday morning. The hills and mountains most certainly will over the next 48 hours and going by the output will remain on the ground for some time. All in all a decent start to the winter imo. We just need a couple of upgrades longer term to bring the threat of snow back. Either way its not going go be mild

[UV-RAY]

There has been a change in the Ecm 00z ensemble mean since the 12z last night, by the weekend the high is further east which means the showery N'ly for the east has gone, it's been shunted much further to the east, however, the ecm mean is cold and anticyclonic with light winds, widespread sharp frosts and an increasing risk of freezing fog. Eventually the high begins to drift southeast but even by T+240 hours it's still covering the whole of the uk but beyond that, the atlantic is knocking on the door to the northwest of the BI but it could mean a spell of cold zonality with the jet axis wnw / ese or better still, nw / se.......but that's into early december and a lot will change, definate eastward shift in the ecm pattern though.

Thats were I envisage any breakdown to come from Frosty, but it won't be a mild pattern rathe like you say cold zonality and with our own cold pool already in place it could surprise a few of us.

[BLAST FROM THE PAST]

Another early crock from ECM as per last year but UKMO was never on board and I agree with Steve Murr, we need that model on board with the ECM for confidence in stellar outcome...never mind, it is still only November.  winter hasn't even started.....but I get the feeling that December is going to be a long month on here.

 

BFTP

Edited November 19, 2013 by BLAST FROM THE PAST