Model Output Discussion - Into 2024

[offerman]

14 minutes ago, Weathizard said:

Key difference, Iberian heights, it’s always the same, the models can be far too overzealous in removing them at times

Completely agree with you there, whether wizard
it seems that the computer models and super computers put in historic data and come up with weather charts/forecasts but what they can’t count for is the increased strength and stubborness of these HPs which have such a dominant effect on our weather, even when they are not direct but to the south and south west. 
 

it’s very difficult for forecasting as that is all it is whether we do what it wants to do, and as someone mentioned that the Arctic is in such a state at the moment of inconsistency there are no really cold, strong drivers coming from there and went up against powerful mild weather types guided warmer ocean temperatures and stronger Iberian and is high-pressure systems. Then it often gets watered down.. 

this is what we are up against now, and it’s gonna be taking quite some time before these changing weather. Patterns can be put into super computer data where they become historical is going to take time for that to be taken into account. when that happens, then we will get more accurate charts coming through as they will have built up enough data from now onwards of the changing patterns. So there should be much less of the inconsistencies that we see in the charts. Examples called cold pressure chance only to be watered down should become much less frequent as they can take into account all of the changing data that’s happening at the moment.

[Ali1977]

ICON at 120 , not as good in Greenland - although trying to look for chinks of light and I’m wondering if the high over the U.K. being slightly further East could help, as when it gets pulled north it should stay slightly further east - then the Arctic trough will be aligned better to hit the U.K. !! Maybe!!

Edited January 7 by Ali1977

[Ali1977]

GFS upgrades the uppers again on Monday, therefore even more widespread snow showers possible 

[offerman]

21 minutes ago, frosty ground said:

Key difference is the lack of Greenland high due to issues over the pole and Greenland the outcome is higher heights over Iberia.

the outcome is not the cause, it’s not the Hadley cell expanding its other factors 

Good post Frosty. But the fact of the lack of Greenland and Arctic Heights is allowing Iberian and Hadley cells to expand as everything is out of kilter 

if you had an expanding Greenland high and Arctic high, this could balance things out, and probably reduce the constant influence of the resource, and Iberian Heights.

so good post from you as to look at it from that direction of the lack of the Heights in the north.

 

I guess the way I could summit up is look at it like a pair of scales.

On the left side, let’s go it, Greenland Arctic Heights and on the right side let’s call it, Iberian , Hadley cell azores.

If we reduce the weight on the left side, then the right side will be the dominant factor.

 

so thanks for your post. Good information that Adds to the reasoning of the high-pressure systems dominance to our south, which I sometimes post about. 
 

I guess the next thing we could look at is, why are the Greenland and Arctic Heights so much less dominant than they were previously, and also as someone mentioned earlier, there is no consistency on a day-to-day basis. 

is this down to a disrupted or broken current polar vortex or is this something else? 

 

[January Snowstorm]

2 minutes ago, Ali1977 said:

GFS upgrades the uppers again on Monday, therefore even more widespread snow showers possible 

Yes a nudge in the right direction! Those small nudges could make a big difference if they were to continue

[Mike Poole]

ECM clusters this morning, taken a while to access the site, not sure it was really worth it, because there is only one cluster in the key timeframe.  Anyway, here they are right through from T120:

From the first timeframe, it does seem that the idea of heights failing to get into Greenland to start with (yesterday’s ECM 0z) has gone, which is a positive.  All I will say about the second timeframe, is that the representative member chosen actually isn’t bad!  In the extended, still a lot of uncertainty, the pattern looks more mobile though, how far south the jet is running with that may be important for some areas that can hang on to any cold air.  

[weathercold]

1 hour ago, Met4Cast said:

There’s no two ways about it really, this is a poor set from the EPS. 

The wheels have been falling off for days now. There is absolutely no deep freeze likely sadly. Expected a few chilly days especially down south with temps above freezing by day. No sustainable high lat blocking… from where we were under a week ago this is another failed chase sadly.

Hopefully one will come to pass before winter is over.

[Ice Day]

A very downbeat mood on here this morning. FWIW I thought the GFS and UKMO were good in the reliable, the GEM was excellent and the ECM was at least better than yesterday's. No doubt, the downgrades of the means is a concern, but they can really flip at the drop of a hat, either way!

Hopefully, the 12z change the momentum, but remember that FI is around 120 so whatever is shown outside of that, good or bad, is very much just for fun.

Eyes down for an improved 6z.

 

[AO-]

EC the worst EPS of the three models I can compare at WZ for my location. EC is usually superior, but on the long term I am not so sure. All the models have their biases. 

 

[mountain shadow]

My summary of the overnight runs is a delay to the cold arriving and the depth of cold has been watered down.

Still time for change but for Southern areas especially the risk of snow has lowered. 

Still time for change though as the models struggle with the strat warming.

[syed2878]

55 minutes ago, WINTRY WALES said:

Gong to be some right pants pulled down here unfortunately if this does turn out to be standard January weather from mid month. That’s not a dig or anything like that as all the teleconnectiins etc pointed towards that. More so points to the fact that nearly all most understood drivers were lining up in a positive way and the technical guys feeling comfortable yet “maybe” the blinking wheels are still falling off .

 Excellent Post, the cold spell now looking like the wheels are falling off. This is why I never pay too much attention to tell connections. Fairplay to those who do use Telekon connections, but I don’t think they can be used as a forecasting tool for the UK. I must say disappointing ECM for the last day or two.

[Met4Cast]

2 minutes ago, Harveyslugger said:

Is it actually snowing in the SE?or is it wrong

I've seen a couple of reports but I think any wintriness mostly confined to above 200-300m, the WBFL is around 600-800m in that area. 

1 minute ago, weathercold said:

The wheels have been falling off for days now. There is absolutely no deep freeze likely sadly. Expected a few chilly days especially down south with temps above freezing by day. No sustainable high lat blocking… from where we were under a week ago this is another failed chase sadly.

Hopefully one will come to pass before winter is over.

Deep cold was always a low likelihood outcome on the ensemble suites despite some very enthusiastic det outputs. 

[Harsh Climate]

2 minutes ago, Ice Day said:

A very downbeat mood on here this morning. FWIW I thought the GFS and UKMO were good in the reliable, the GEM was excellent and the ECM was at least better than yesterday's. No doubt, the downgrades of the means is a concern, but they can really flip at the drop of a hat, either way!

Hopefully, the 12z change the momentum, but remember that FI is around 120 so whatever is shown outside of that, good or bad, is very much just for fun.

Eyes down for an improved 6z.

 

Yeah not sure why the downbeat mood, everything still looking very good.

GFS AVG 240H

ECM 240H

UKMO 168H

GEM 240H

JMA 240H

All very good at 240h, which is already way out the reliable timeframe, forget what some are showing after. Yes these charts aren't the 10/10 FI charts we been spoilt with over the last few days but they are still very good.

Forme we have had the expected model wobble, we have had the wobble with the overly good charts a couple of days ago, now we are seeing kind of the other end of the spectrum. Still very good and packed with snow potential in my opinion.

Once we get the cold in, it should be very stubborn to move! The models usually nearly always overplay any return to a more mild/mobile set-up, with the current northern hemisphere profile and background driver signals at worst I see a battleground scenario setting up next week with milder air to the southwest (with rain/sleet) and colder air to the more NE (with snow showers). Perhaps heavy snow where the boundaries meet.

Again, a lot of water to go under the bridge, no alarm bells ringing for me just yet, far from it. 

[Vortex3929]

5 minutes ago, Harveyslugger said:

Is it actually snowing in the SE?or is it wrong

Regional thread says rain. Temperatures and dp are too high still. 

A little disappointing to read that the ECM still isn't being helpful for the cold spell. Adding further to the points raised on why we are seeing "down grades", I'm rehighlighting this point as I think it's quite valid 

1 hour ago, nick sussex said:

This from the latest NCEP extended forecast discussion.

For the next system developing across the southern Plains Friday, the GFS is slower and more amplified with the upper trough compared to the much more progressive ECMWF/CMC, and therefore considerable timing differences with the surface low track (GFS slowest and ECMWF fastest by Friday night). Both the EC and GEFS ensemble means are between these two solutions, and therefore these served as a good proxy for the expected location of the surface low. Model spread becomes high across the eastern Pacific and adjacent portions of the West going into next weekend, and this leads to below average confidence for that region. The ensemble means accounted for 40-60% of the forecast blend going into next weekend to account for the growing model differences.

Now I'm not an expert in this field of model watching, but I do read here a lot. 

Haven't we had to rely on an the Pacific jet to an extent (EAMT etc) ? And this jet somehow matters to our weather ( as per Tamara and met4cast?)... so if there is model spread happening over in the Pacific (and I may be very wrong here!!!! This is purely guess work by me)... would they same model spread not have a similar knock on effect downstream so to speak and there for cause our models to possibly be exhibiting some kind of change or disagreement?

[Biensie]

17 minutes ago, Harveyslugger said:

Is it actually snowing in the SE?or is it wrong

No

[Battleground Snow]

Crazy difference across the arctic and Pacific between the gfs and ecm

I think this run should make it on the 06z

[Catacol]

Some things never change. It is as though model watchers wake up every morning determined to be gloomy.

ECM 240

GFS 240

GEM 240

I'd give my right army for charts like these in any winter. 

My only comment would be to address the delay issue. Those long in the tooth on watching models know that high pressure is often, if not always, modelled to move faster than actually occurs in practice. So seeing the trough arrive a day or two later fits the observation. No issue with this provided we maintain low pressure to the south and dont see a sub-tropical high resurge. Any signs of this?

Well - on the EPS not really at realistic range. Weds 17 and the midnight EPS still have pressure lowered over the continent

and yesterday's EPS the same out to 300h.

There are too many on here who get the magnifying glass out at 192h+ and see slight shifts as a disaster. There are always going to be shifts - it is absolutely impossible for one complex run produced out of Tb of data to be the same as another and these will sometimes "improve" or "downgrade". But one thing is for sure - getting hung up on 850 spaghetti charts at 192-240h range is 100% guaranteed to drive you nuts. As I said yesterday NWP is hopeless at getting 850s right even within high resolution range, and an 850 spaghetti does not really therefore give you much of an idea of synoptics.

Enjoy the ride. This has a long way to run yet - hopefully a very long way to run. Patience, stamina and a very healthy dose of perspective required.

Edited January 7 by Catacol

[ItNeverSnowsInWindsor]

25 minutes ago, weathercold said:

The wheels have been falling off for days now. There is absolutely no deep freeze likely sadly. Expected a few chilly days especially down south with temps above freezing by day. No sustainable high lat blocking… from where we were under a week ago this is another failed chase sadly.

Hopefully one will come to pass before winter is over.

No one has been predicting a deep freeze except a few on here.

[Cymro]

Come back tomorrow evening and all will be joyous and happy, today would be a good day for a break, get out and enjoy the crisp cold air! 

There's enough divergence beyond the reliable for plenty of upgrades yet! 

[IDO]

GFS 06z very consistent with the 0z, only subtle differences by D6-7:

So, again no shortwave drama. See if FI changes post-D7.

 

 

[seabreeze86]

Really just shows how insanely good the charts have been if this is being kicked out of bed 

[Battleground Snow]

Just now, seabreeze86 said:

Really just shows how insanely good the charts have been if this is being kicked out of bed 

It's very quiet in here terms of posts on it! Might even cut off the high soon 

[Ali1977]

Better over Greenland - could be a better run 

[MJB]

Any other year or period of standard weather model watching everyone on here would be going mental about this chart but no...............the wheels are falling off, the trouble is guys you see charts like these ( mid term, and close to reliable) yet the judgement is made on charts at 240 / 264 and beyond ( outside the reliable and well into FI )

Baffling 

[Weathizard]

Just now, seabreeze86 said:

Really just shows how insanely good the charts have been if this is being kicked out of bed 

The issue is the period after this chart though, as most have said the period between 120/168 appear to be going well but then the blocking dramatically weakens and we end up in a damp squib