Page History

...

The details of each forecasting system correspond to the values of the "system" keyword (as used both in the CDS API and on the CDS interactive download forms). A full description of the use of that keyword and its correspondence with the different forecast systems names is available from the "Description of the C3S seasonal multi-system" page.

Nominal Start Dates	C3S multi-system operational components ('system' keyword values)
Nominal Start Dates	ECMWF	Météo-France	UK MetOffice	DWD	CMCC	NCEP	JMA	ECCC	BOM
September 2017 - October 2017	4	5	12
November 2017 - April 2018	5	5	12 ⁽¹⁾
May 2018 - October 2018	5	5	13
November 2018 - April 2019	5	6	13	2	3
May 2019 - September 2019	5	6	14 ⁽²⁾	2	3
October 2019 - April 2020	5	7	14	2	3	2
May 2020 - September 2020	5	7	15	2	3	2
October 2020	5	7	15	2	35	2	2
November 2020 - February 2021	5	7	15	21	35	2	2
March 2021 - April 2021	5	7	600	21	35	2	2
May 2021 - June 2021	5	7	600	21	35	2	2	1 and 2
July 2021 - November 2021	5	8	600	21	35	2	2	1 and 2
December 2021 - January 2022	5	8	600	21	35	2	2	2 and 3
February 2022	5	8	600	21	35	2	3	2 and 3
March 2022 - October 2022	5	8	601	21	35	2	3	2 and 3
November 2022 - Februrary 2023	51 ⁽³⁾	8	601	21	35	2	3	2 and 3
March 2023⁽⁴⁾ - February 2024	51	8	602	21	35	2	3	2 and 3
March 2024 - June 2024	51	8	603	21	35	2	3	2 and 3
July 2024	51	8	603		35	2	3
August 2024 - February 2025	51	8	603	21	35	2	3	4 and 5
March 2025	51	8	604	21	35	2	3	4 and 5
April 2025	51	8	604	22	35	2	2	4 and 5

Legend:

bold font	forecast systems introduced for the first time at the beginning of the nominal start dates range
non-bold font	forecast systems that were excluded from the multi-system at that time

Notes:

⁽¹⁾ From February 2018: upgrade on data provision: changes in set of parameters available, see column noted with 'C3S-0.1 netcdf' in this link. Data deficiencies fixed, see known issues D2 and D3.
⁽²⁾ Data deficiencies fixed, see known issue D9.
⁽³⁾ Due to technical reasons, a new version of ECMWF SEAS5 data has been created using the keyword system=51.

Expand

title	See additional information about ECMWF system=51

Starting from November 2022 a new version of ECMWF SEAS5 output has been introduced in C3S. This new version (v5.1) has been labelled with the keyword system=51

What are the changes in this new version of ECMWF SEAS5 data?
- A different interpolation tool has been used to produce the 1-degree grid, both for hindcasts and real-time forecasts.
- A new 1-degree grid, now consistent with the grid available from the other participating forecast systems. Specifically, it will have grid-points centered at half-degree latitude/longitude, and hence it has 180 values in the latitude coordinate (from -89.5 to 89.5) instead of the current 181 values (from -90 to 90)
- A couple of additions to complete the list of available variables: Top solar incoming radiation and 1000hPa level for the 5 variables available at pressure levels. Additionally, on top of the values of runoff, for SEAS5.1 both sub-surface and surface runoff will be also available.

What are the implications for users of ECMWF SEAS5 data?
- From November 2022, only system=51 real-time forecast data will be available from the CDS
- Users will need to use system=51 hindcast data alongside the new real-time forecasts.
  Data from the current version (system=5 ) should not be used, so those users with previously downloaded hindcast data will need to download the new version.

Why have these changes been introduced?
- When ECMWF SEAS5 was released in 2017, the C3S 1-degree version was created with the default interpolation tool (emoslib ) available from MARS. With the migration of ECMWF computing infrastructure to its new Data Centre in Bologna, this tool has been discontinued. That means new real-time forecasts produced after the migration can't be produced anymore in a way consistent with the available SEAS5 hindcast in the CDS. After careful evaluation of the impact of the interpolation, it was decided to create a new version of the hindcast data. This has been labelled as SEAS5.1 and encoded with keyword system=51.
- With this new version of SEAS5 hindcast, a couple of additional improvements were also included:
  - A new 1-degree grid consistent with the one provided for other forecast systems (see details above)
  - A couple of additions to the list of variables (see details above).

⁽⁴⁾ From March 2023 a dataset with ocean variables is available from the CDS catalogue (see details on availability here).

Hindcasts

Nominal start date	ECMWF			Météo-France				Met Office^(a)									DWD			CMCC		NCEP	JMA		ECCC					BOM	Nominal start date
Nominal start date	System 4 (system=4)	SEAS5 (system=5)	SEAS5 (system=51)^(b)	System 5 (system=5)	System 6 (system=6)	System7 (system=7)	System8 (system=8)	GloSea5-GC2 (system=12)	GloSea5-GC2 (system=13)	GloSea5-GC2-LI (system=14)	GloSea5-GC2-LI (system=15)	GloSea6 (system=600)	GloSea6 (system=601)	GloSea6 (system=602)	GloSea6 (system=603)	GloSea6 (system=604)	GCFS2.0 (system=2)	GCFS2.1 (system=21)	GCFS2.2 (system=22)	SPSv3 (system=3)	SPSv3.5 (system=35)	CFSv2 (system=2)	CPS2 (system=2)	CPS3 (system=3)	GEM-NEMO (system=1)	CanCM4i (system=2)	GEM5-NEMO (system=3)	CanESM5.1p1bc (system=4)	GEM5.2-NEMO (system=5)	ACCESS-S2 (system=2)	Nominal start date
January								^(c)	^(c)	^(c)	^(c)	^(c)	^(c)	^(c)	^(c)																January
February																															February
March																															March
April																															April
May

	May
June

	June
July		July
August		August
September		September
October		October
November		November
December		December

^(a)For the Met Office contribution, due to the production of hindcasts "on-the-fly", the CDS keyword 'system' does not have the same meaning as for the other contributors. More details here.
^(b) Due to technical reasons, a new version of ECMWF SEAS5 data has been created using the keyword system=51. See details on Announcements (date 12/October/2022)
^(c) Hindcast data for January 1993 is not available from MetOffice forecast systems (see "known issue" G4 on the data gaps section)

...

Space shortcuts

Page tree

Versions Compared

Old Version 291

New Version 292

Key

Hindcasts