Model Output Discussion - mid Autumn

[Jacob]

[MJB]

Control develops well 

Ends with more promise

 

All JFF but nice to see

[Mike Poole]

1 hour ago, Cold Winter Night said:

The most up-to-date ECMWF Forecast User Guide answers these questions:

"The horizontal and vertical resolutions of the medium range ensemble (ENS) became the same as for the HRES after the upgrade to IFS (Cy48r1) introduced in June 2023.  The HRES forecast and the unperturbed ENS control forecast are meteorologically equivalent and equally skilful on average.  They have the same physical and dynamical representation of the atmosphere and use the same parameterisation of sub-gridscale effects.  However, they can diverge on a day-to-day basis due to small technical differences and the chaotic nature of the atmosphere.  The HRES will continue for the time being for ease of use by customers and users."

So yes, they are basically identical, but they still run separately. The small differences in outcome are the result of the element of atmospheric chaos that is integrated in the model, and small technical differences.

The separate Operational run still exists as a separate thing, because all of us, pro forecasters and amateurs alike, are so used to it. That is of course very considerate of them, but I assume we can expect it to be discarded in future updates....

 

Section 2.1.2.4 HRES - High Resolution Forecasts - Forecast User Guide - ECMWF Confluence Wiki

CONFLUENCE.ECMWF.INT

 

Many thanks for finding the answer to this question, which has perplexed me since the ECM EPS upgrade took place.  

I would argue that the control days 10-15 now warrants some additional attention paid to it.

[Lukesluckybunch]

2 minutes ago, MJB said:

Control develops well 

Ends with more promise

 

All JFF but nice to see

absolute fantastic to look at..a rinse and repeat theme.

[Lukesluckybunch]

can not wait for the 12z..key timeframe being 168h onwards..the high to the southwest moves in settles over the uk..then moves northwest toward greenland!

[seabreeze86]

And we are off 

Back to the late’s nights refreshing meteociel repeatedly for a hour awaiting the 18z , only to wake up to the 0z is completely different as it’s found a shortwave out of nowhere. 
 

We we eventually get cross model agreement but then it will look dry

[Cold Winter Night]

5 minutes ago, Mike Poole said:

Many thanks for finding the answer to this question, which has perplexed me since the ECM EPS upgrade took place.  

I would argue that the control days 10-15 now warrants some additional attention paid to it.

Absolutely.

With an ECM Control that is at the same skill level as the Operational already was, it means that it is also equally superior to the UKMO, GFS, GEM operational runs.

Plus having the EC Operational and Control running side by side gives us more insight in the influence of atmospheric chaos on the output.

[Cambrian]

A key chart for me today is the 0z EPS 500 chart for day 12. Solid heights to the west and northwest, determined trough to the northeast, and the way that it can be taken in tandem with 6z GEFS mean anomalies, here from the 6z run.

 

This setup is now serving as the general theme for a pleasing emergence of cross-model consensus across the suites - rare to see such a consensus at day 12 on a single set of runs, let alone run after run, day after day. 

0z ECM control, 0z GEM control, 6z GFS op, even the 0z JMA (at the end of its run at day 11, but day 12 is easily imagined!)

   

And this striking setup creeping into the ensemble means for the same timeframe now too. 

[northwestsnow]

Exeter having nothing to do with EC or GFS ,if anything their updates suggests Euro High or HP to the south .

Edited November 13, 2023 by northwestsnow

[Robbie Garrett]

2 minutes ago, northwestsnow said:

Exeter having nothing to do with EC or GFS ,if anything their updates suggests Euro High or HO to the south .

Part of the long-range forecast not updated yet; Updated: 15:00 (UTC) on Sun 12 Nov 2023

Normally done by 1500.

[TSNWK]

1 minute ago, northwestsnow said:

Exeter having nothing to do with EC or GFS ,if anything their updates suggests Euro High or HO to the south .

Oh.. and I was going pull up a chair with a cuppa and watch the 12z roll out..  feels like I should not bother now?

[northwestsnow]

Just now, Robbie Garrett said:

Part of the long-range forecast not updated yet; Updated: 15:00 (UTC) on Sun 12 Nov 2023

Normally done by 1500.

EC 00z is within the first update period.

Just now, TSNWK said:

Oh.. and I was going pull up a chair with a cuppa and watch the 12z roll out..  feels like I should not bother now?

I wouldn't say that but i was hoping for a flip in the update ..

 

 

[MattStoke]

14 minutes ago, TSNWK said:

Oh.. and I was going pull up a chair with a cuppa and watch the 12z roll out..  feels like I should not bother now?

Big fan of the Met Office but that medium term outlook is normally poor for accuracy.

Edited November 13, 2023 by MattStoke

[swfc]

11 minutes ago, northwestsnow said:

EC 00z is within the first update period.

I wouldn't say that but i was hoping for a flip in the update ..

 

 

Tbh there output hasnt covered itself  in glory. Im pretty sure there is a lag on there forecasts ie human input

[Mike Poole]

Just now, swfc said:

Tbh there output hasnt covered itself  in glory. Im pretty sure there is a lag on there forecasts ie human input

Yes, there will be a lag, they need time to evaluate all the model output, then decide on their forecast, then decide how to communicate it.  And it updates once or twice a day, so I would factor that in, and suggest that it is based on model output at least 1 or 2 suites behind what we’re looking at.

And for the 2-4 week period, it will surely major on the ECM 46, of which today’s run is not yet out.  And, as we’ve discussed, it is rather dismissive of the evolution the op runs are coming up with anyway.

[CoventryWeather]

Well ICON DWD model says otherwise at 180, follows suite. I think this is becoming a trend, it's just whether it downgrades in the coming days/week. 

And to mention the met and ECM 46, they are means of all models, and likely not to pick up changes that suddenly really, likely to pick up on it in the coming days as the signal increases somewhat.

[TSNWK]

8 minutes ago, MattStoke said:

Big fan of the Met Office but that medium term outlook is normally poor for accuracy.

Thanks... I kind of wish Met-office updates were not in this place - can potentially put a downer on things, bit like trying to watch the football highlights when you know the outcome and have lost...

Eyes down Gfs12 is a running.

[booferking]

We must wait for met office confidence as long as the ops keep showing outlook update will change.

[rwtwm]

5 hours ago, Mike Poole said:

That is precisely the point of my question.  For the ECM op and the new EPS control, it isn’t any more.  They are all run at 9km horizontal and 137 vertical levels.  The control is unperturbed (as is the op).  So what is the difference?

I was intrigued, so I went and had a dig through the ECM documentation.

Confluence Mobile - ECMWF Confluence Wiki

CONFLUENCE.ECMWF.INT

They are apparently basically the same and only diverge due to "small technical differences and the chaotic nature of the atmosphere"...

There's no more detail than that. Maybe floating point truncation plays a part?

Edit* I see I was beaten to the punch 

Edited November 13, 2023 by rwtwm
Acknowledge duplication

[Mucka]

GFS 12z Op very different to this mornings 00z by day 7 and more in line with ECM with having the high further W although still not as amplified in the Atlantic at this point.

GFS 12z/00z

Check the difference in orientation of the high as well.

Edited November 13, 2023 by Mucka

[Neilsouth]

Hey all, can someone post some charts for this weekend? ( Important ) Thank you :)

[TSNWK]

intresting Gaps over Green land where the Vortex should - could be a goody around day 10 / 11

 

[Lukesluckybunch]

straight northerly at day 10..but less amplification,compare to 6z..UK high incoming i think on this run

Edited November 13, 2023 by Lukesluckybunch
adding

[tight isobar]

As raws go- I’d await the complete set of 12z- as the gfs comes a little more in line with the ecm. And look for solidity’s or any backtracking!..

[John88B]

A quick question about the Met Office. What other tools, models, do they have at their disposal that we don't get to see?

Cheers in advance