Model Output Discussion - Winter arrives

[MATTWOLVES 3]

Can I just say guys,why is it when we are searching for cold or heat in summer,we have to start getting into a debate over which forecasting tool is best! Noaa or the ops and ens!

All methods ain't fool proof! Each have there purposes,and tbh beyond a 10 day timescale,both can be made to look silly! Because the weather makes mugs of us all,and simply does not care which method your using!

There is no such thing as this method is best...every method out there can be made to look stupid regarding our volatile NW Hemisphere!

Edited November 27, 2021 by MATTWOLVES

[Battleground Snow]

17 minutes ago, mushymanrob said:

 

Youre both missing the point.... The ops show all kinds of FI options, some of which will identify an emerging pattern first. And its true the Anomalies dont always show an emerging pattern first, but they do show an emerging pattern most accurately. For example, just go to day ten, t240 and see how many different options there are, one of which is likely to be right, but which one?... the one (or more) closest to what the Anomaly mean charts suggest will always be the most likely to verify.

Now im not saying that there wont be a scandinavian high developing, im saying that as things stand, there is no scandinavian high on these charts for this timeframe, so until there is, the current ops showing it will most likely be proven inaccurate.



 

I'm sorry, but I just don't think this is true, my understanding of those NOAA 500mb charts is they that use a blend of ensemble means, mostly GFS and ECM, that are sometimes tweaked by professional forecasters at NOAA.

A blended mean is always going to be behind the curve of the higher resolution det runs. They might give a more accurate picture of the northern hemisphere in terms of the longwave pattern because everything is smoothed at range on a blended mean, but specifics are very important for the UK's fortunes for example a high modelled a few hundred miles north into Scandinavia on a det run will cause a drastic difference to surface conditions compared to a  mean that has a sceuro anomaly.

[Battleground Snow]

GFS and ECM (bias corrected) are just about holding onto phase 6, if we do get a scandi high it may not last very long, need it to continue into 7 really, I guess la Nina strength is making this difficult.

[MATTWOLVES 3]

3 minutes ago, Battleground Snow said:

GFS and ECM (bias corrected) are just about holding onto phase 6, if we do get a scandi high it may not last very long, need it to continue into 7 really, I guess la Nina strength is making this difficult.

What ya think mate...we are certainly seeing the evidence of la nina right now...strong Atlantic ridge holding off the Atlantic weather machine! 

I'm always sceptical on these events in all honesty,yes they play a role in our conditions,but not to the extent they do in parts of the USA,Indonesia and Australia for instance. The la nina regime can increase the storminess over the Arctic regions and lead to us becoming milder and wetter later into the season...but with so many other variables at play and contrasting signals,it's probably best to keep an open mind!

We've seen very positive teleconnections in the past (2019) for instance bring us nothing!and we have seen poor signals deliver us the goods.

So I for one will be keeping an open mind on how this season plays out.

[Battleground Snow]

12 minutes ago, MATTWOLVES said:

What ya think mate...we are certainly seeing the evidence of la nina right now...strong Atlantic ridge holding off the Atlantic weather machine! 

I'm always sceptical on these events in all honesty,yes they play a role in our conditions,but not to the extent they do in parts of the USA,Indonesia and Australia for instance. The la nina regime can increase the storminess over the Arctic regions and lead to us becoming milder and wetter later into the season...but with so many other variables at play and contrasting signals,it's probably best to keep an open mind!

We've seen very positive teleconnections in the past (2019) for instance bring us nothing!and we have seen poor signals deliver us the goods.

So I for one will be keeping an open mind on how this season plays out.

I think we have a good chance of a scandi high in 7-10 days time, which will be mainly cold and dry. I don't think it will last many days, with the strong vortex pushing it away to the east.

If the block can become more robust, then lows spawning off the vortex to the north west may disrupt under the block and then the real fun and games may start.

 

Edited November 27, 2021 by Battleground Snow

[johnholmes]

24 minutes ago, Battleground Snow said:

I'm sorry, but I just don't think this is true, my understanding of those NOAA 500mb charts is they that use a blend of ensemble means, mostly GFS and ECM, that are sometimes tweaked by professional forecasters at NOAA.

A blended mean is always going to be behind the curve of the higher resolution det runs. They might give a more accurate picture of the northern hemisphere in terms of the longwave pattern because everything is smoothed at range on a blended mean, but specifics are very important for the UK's fortunes for example a high modelled a few hundred miles north into Scandinavia on a det run will cause a drastic difference to surface conditions compared to a  mean that has a sceuro anomaly.

mushy has the right idea in my view, based on getting on for 15 years of using them. They do require a lot of practice interpreting them but at T+240, for example, they are 70-80% more likely to have the correct 500 mb pattern than any of the 2 or 4x daily, what I call, synoptic model outputs. That statement is based on first of all a 3 years test over a whole 12 months in the 3 years so summer and winter about 12 years ago and using them since.

One other suggestion for new folk; beyond T+144, on average, do not check one run with the last run, check like with like so 12 z today with 12 z yesterday. Honest you will get a less volatile run of charts if you do. It won't always work but it will in most cases. Below T+144 than the newer T+00 data on each run will, as T+00 approaches, give a more accurate assessment.

[Cold Winter Night]

Despite some dismissing the idea, Scandi Heights rises do show up, not in just one rogue GFS pub run, but consistently so on the GFS Op and GEFS, and also on the EC Op and in the extended EPS.

At 360h there is one cluster that has enough Scandi/Northern UK Height rises for the algorithm to assign it to the red-bordered BLO+ regime.

The other two clusters, although assigned to the NAO+ regime, still feature considerable heights East and Northeast of Scandinavia.

The BLO+ cluster shows its hand in the De Bilt output, with a decent group of wind directions from the Northeasterly to the Southeast at Days 9-15.

The serious cold they could bring is clearly visible in the De Bilt 2m plume at the end:

The regime chart is, compared to yesterday, less eager to move to NAO+ and remains fairly weak in any direction.

All this promises absolutely nothing for coldies (or mildies), but the possibility of NE height rises is, although perhaps modestly so, really present in the output, without having to resort to hopecasting or something.

[Mike Poole]

5 minutes ago, Cold Winter Night said:

Despite some dismissing the idea, Scandi Heights rises do show up, not in just one rogue GFS pub run, but consistently so on the GFS Op and GEFS, and also on the EC Op and in the extended EPS.

At 360h there is one cluster that has enough Scandi/Northern UK Height rises for the algorithm to assign it to the red-bordered BLO+ regime.

The other two clusters, although assigned to the NAO+ regime, still feature considerable heights East and Northeast of Scandinavia.

The BLO+ cluster shows its hand in the De Bilt output, with a decent group of wind directions from the Northeasterly to the Southeast at Days 9-15.

The serious cold they could bring is clearly visible in the De Bilt 2m plume at the end:

The regime chart is, compared to yesterday, less eager to move to NAO+ and remains fairly weak in any direction.

All this promises absolutely nothing for coldies (or mildies), but the possibility of NE height rises is, although perhaps modestly so, really present in the output, without having to resort to hopecasting or something.

Yes, I agree, the signal is there for blocking into Scandi, it has been for at least a couple of days as a possible destination.  It is not big, sure, but it one option that must be on the table 10-15 days hence.

[mushymanrob]

43 minutes ago, Battleground Snow said:

I'm sorry, but I just don't think this is true, my understanding of those NOAA 500mb charts is they that use a blend of ensemble means, mostly GFS and ECM, that are sometimes tweaked by professional forecasters at NOAA.

A blended mean is always going to be behind the curve of the higher resolution det runs. They might give a more accurate picture of the northern hemisphere in terms of the longwave pattern because everything is smoothed at range on a blended mean, but specifics are very important for the UK's fortunes for example a high modelled a few hundred miles north into Scandinavia on a det run will cause a drastic difference to surface conditions compared to a  mean that has a sceuro anomaly.

Well ive been using them myself for 7-8 years now and im confident with using them as a guide, a skeleton to build on. Yes they are a blend and yes the GFS goes out further ahead than the anomalies timeframe. Thats the very point, they DO give a more accurate picture of the long wave pattern, so there will be no strong lasting high pressure in a place these charts dont allow for one.

Ive lost count of the number of times ive posted "evidence" on here, and i find that people dont like these charts when they dont support the desired outcome, but i view charts for accuracy, not because im "weather type chasing".

But lets just see, if the GFS is onto something around day 10, then the Anomalies will soon shift to reflect that. If they dont then the GFS yet again is leading you up the garden path of false hope.... and THATS why i rely on those charts, to avoid false hope. Currently at day ten theres everything from high pressure somewhere nearby to a dartboard low over us on the ops... The Anomalies suggest for the 6-14 day timeframe a pretty moderate Westerly upper flow with slight negative pressure anomalies over us. As @knocker pointed out earlier, pretty normal, average Westerly based unsettled is most likely for this timeframe as things stand atm.

[mushymanrob]

Why do people call it the "pub run"?.... The GFS is American, so when its issued here, its afternoon there!

Edited November 27, 2021 by mushymanrob

[Battleground Snow]

9 minutes ago, mushymanrob said:

Well ive been using them myself for 7-8 years now and im confident with using them as a guide, a skeleton to build on. Yes they are a blend and yes the GFS goes out further ahead than the anomalies timeframe. Thats the very point, they DO give a more accurate picture of the long wave pattern, so there will be no strong lasting high pressure in a place these charts dont allow for one.

Ive lost count of the number of times ive posted "evidence" on here, and i find that people dont like these charts when they dont support the desired outcome, but i view charts for accuracy, not because im "weather type chasing".

But lets just see, if the GFS is onto something around day 10, then the Anomalies will soon shift to reflect that. If they dont then the GFS yet again is leading you up the garden path of false hope.... and THATS why i rely on those charts, to avoid false hope. Currently at day ten theres everything from high pressure somewhere nearby to a dartboard low over us on the ops... The Anomalies suggest for the 6-14 day timeframe a pretty moderate Westerly upper flow with slight negative pressure anomalies over us. As @knocker pointed out earlier, pretty normal, average Westerly based unsettled is most likely for this timeframe as things stand atm.

It's not about "not liking" what they show, it's when it's clear to see they didn't show an Atlantic ridge and then one did happen, so we are not allowed to call that out as an inaccurate prognosis?

Phrases such as "weather chasing" and false hope" are immature. You can still want cold / extreme pattern to materialse and have a understanding of meteorology/ improve learning at the same time. It may seem like a bias because not many people want to discuss the standard south Westerly airstream we get 80% of the year.

Knocker was mainly referring to extended ecm and ec46 when talking of a mainly westerly based unsettled theme. Being so far out these are more liable to change or even flip.

 

I agree let's see how the models continue over the coming days to see which regime is more likely in 10 days, a Westerly flow or a slack continental one.

 

[Floatylight]

30 minutes ago, mushymanrob said:

Why do people call it the "pub run"?.... The GFS is American, so when its issued here, its afternoon there!

I always believed the ecm was the pub run?

[bluearmy]

It could be noted that the cpc charts ahead of this period never showed a particularly marked upper ridge to our west - certainly not gaining traction into greeny as a specific feature (as we saw on many ops and the odd means )

rhe cpc does have some op inclusion during the week if the forecaster feels relevant 

Use of the cpc charts has to be alongside all the other output - it’s often quite obvious to the saddest among us who look at too many runs and suites when cpc is behind the curve. 
 

 

Edited November 27, 2021 by bluearmy

[Methuselah]

There have been rare occasions when an operational run 'got there' earlier than the anomalies did. But as the ops are usually spouting, at least partial, nonsense (in that they flap around likes sheets in the wind), I'd cast my vote in favour of the anoms.

[MATTWOLVES 3]

40 minutes ago, mushymanrob said:

Why do people call it the "pub run"?.... The GFS is American, so when its issued here, its afternoon there!

I always thought it was due to the fact its nearly always punch drunk when it delivers its forecast

[winterof79]

1 hour ago, Cold Winter Night said:

Despite some dismissing the idea, Scandi Heights rises do show up, not in just one rogue GFS pub run, but consistently so on the GFS Op and GEFS, and also on the EC Op and in the extended EPS.

At 360h there is one cluster that has enough Scandi/Northern UK Height rises for the algorithm to assign it to the red-bordered BLO+ regime.

The other two clusters, although assigned to the NAO+ regime, still feature considerable heights East and Northeast of Scandinavia.

The BLO+ cluster shows its hand in the De Bilt output, with a decent group of wind directions from the Northeasterly to the Southeast at Days 9-15.

The serious cold they could bring is clearly visible in the De Bilt 2m plume at the end:

The regime chart is, compared to yesterday, less eager to move to NAO+ and remains fairly weak in any direction.

All this promises absolutely nothing for coldies (or mildies), but the possibility of NE height rises is, although perhaps modestly so, really present in the output, without having to resort to hopecasting or something.

The Easterly feed option is definitely on the table in the extended.Wind direction and temp 

[knocker]

16 minutes ago, bluearmy said:

It could be noted that the cpc charts ahead of this period never showed a particularly marked upper ridge to our west - certainly not gaining traction into greeny as a specific feature (as we saw on many ops and the odd means )

rhe cpc does have some op inclusion during the week if the forecaster feels relevant 

Use of the cpc charts has to be alongside all the other output - it’s often quite obvious to the saddest among us who look at too many runs and suites when cpc is behind the curve. 
 

 

I obviously  don't know precisely when you are talking about but they certainly did. I suspect one of the problems  is that some people misuse them and that sometimes there is a bit of a lag with the 8-14 in a rapidly changing pattern

Edited November 27, 2021 by knocker

[nick sussex]

First model out the ICON has trended towards the earlier GFS runs  . Not quite enough sharpness to the upstream troughing but still not a bad start.

[MATTWOLVES 3]

8 minutes ago, nick sussex said:

First model out the ICON has trended towards the earlier GFS runs  . Not quite enough sharpness to the upstream troughing but still not a bad start.

I can't keep up with all your places of residency Nick...I think you've got houses all over Europe mate  

Yeh icon not without interest...could be worth keeping an eye on mid next week as well.

[Ali1977]

In the nearer term there’s Another little front coming down from the north could provide a covering for some

[tight isobar]

Just to say- then I’m pulling away from this.  This is 1 of many - many reasons I’m a weather annorak! The non exact science- and deciphering is mesmerising In itself. With all the tools/ data we are spoiled with now- it’s the human input- interpretation, that ultimately- or otherwise fails- or succeed!!. Anyway back to the now output

[nick sussex]

14 minutes ago, MATTWOLVES said:

I can't keep up with all your places of residency Nick...I think you've got houses all over Europe mate  

Yeh icon not without interest...could be worth keeping an eye on mid next week as well.

My French adventure came to an end and I’m splitting my time between Eastbourne and Cyprus where I have lots of family .

It seems a bit strange seeing all the Xmas decorations up and the weathers still quite warm here in Cyprus . 

My new early projection technology is being wheeled out this evening and will be making an early Scandi high projection at T168 hrs based on preliminary results ! 

Lets hope it doesn’t go the way of CNN and Florida in 2000! 

 

Edited November 27, 2021 by nick sussex

[Mike Poole]

35 minutes ago, MATTWOLVES said:

I always thought it was due to the fact its nearly always punch drunk when it delivers its forecast

No, it is because a sizeable proportion of us lot, have been down the boozer when we view it at 10pm ish.

[SLEETY]

ukmo looks good at 120

 

[Griff]

Deja vu..