This table shows the centres that provide data to this project together with the latest configuration of their systems. Follow the link of each Data Provider for specific model description.


 Status on
Time range
(forecasts and
hindcasts)
Forecast initial
conditions
Forecast
ensemble size
Hindcast
initial conditions
Hindcasts
ensemble size
Hindcast period

Hindcast
production
schedule

Resolution of
atmospheric model

Resolution of
ocean model

ECMWF
(ecmf)
215 days 1st of month 51 members 1st of month251981-2016fixed

TCO319/L91

Dynamics:TCO319 cubic octahedral grid

Physics: O320 Gaussian grid (36 km)

91 levels in vertical, to 0.01hPa (80km)

0.25° ORCA grid

75 levels in vertical

UKMO
(egrr)
215 days each day of month 2 members/day(4)

1st, 9th, 17th, 25th

of month

7 members/start

time

1993-2016on-the-fly(1)

N216/L85

0.83° x 0.56° (~ 60km in mid-latitudes)

85 levels in vertical, to 85km

0.25° ORCA grid

75 levels in vertical

Météo-France(3)
(lfpw)
7 calendar months

last and penultimate Thursday of previous month

1st of month

25 members each

1 member

last and penultimate Thursday of previous month

1st of month

12 members each

1 member

1993-2018fixed

TL359/L137 (0.5°)

137 levels in vertical, to 0.01hPa

0.25° ORCA grid

75 levels in vertical

DWD
(edzw)
6 calendar months1st of month

50 members

1st of month30 members1993-2019fixed

T127 (~100 km) 

95 levels in vertical, to 0.01hPa

0.4° TP04 grid

40 levels in vertical

CMCC
(cmcc)
6 calendar months1st of month50 members1st of month40 members1993-2016fixed

approx  0.5° lat-long

46 levels in vertical, to 0.2hPa

0.25° ORCA grid

50 levels in vertical

NCEP
(kwbc)

215 days

each day of month

members initialised every 6 hours (at 0h, 6h, 12h and 18h UTC)

4 members/day

every 5 days (5)

members initialised every 6 hours (at 0h, 6h, 12h and 18h UTC)

4 members/start date

1993-2016fixed

T128/L64 (~ 1°)

64 levels in vertical, to 0.02hPa

0.25° (equator) to 0.5° 

40 levels in vertical

JMA
(rjtd)
215 daysevery day of month5 members/day2 start dates lagged by 15 days (6)5 members/start date1993-2016fixed

TL319 (approx. 55km)

100 levels in vertical, to 0.01hPa

0.25° tripolar grid

60 levels in vertical

ECCC (cwao) (3)(7)(8)
CanESM5.1p1bc

(component of CanSIPSv3.0)

214 dayslast day of previous month and
5th to last day of previous month
10 members eachlast day of previous month and
5th to last day of previous month
10 members each1980-2023fixed

T63 (~2.8° lat-long)

49 levels in vertical, to 1hPa

1° ORCA grid

45 levels in vertical

 

ECCC (cwao) (3)(7)(8)
GEM5.2-NEMO

(component of CanSIPSv3.0)

214 dayslast day of previous month and
5th to last day of previous month
10 members eachlast day of previous month and
5th to last day of previous month
10 members each1980-2023fixed

~1.1° lat-long (~110 km)

85 levels in vertical, to 0.1hPa

1° ORCA grid

50 levels in vertical

 


 NOTES

(1) For each real-time forecast start date, the associated hindcast data is produced and made available through the CDS at least one month in advance. The details about data availability can be found in "Summary of available data" page.

(2) The production schedules of forecasting system with lagged start dates don't prescribe how to build an ensemble for a specific nominal start date. The choices currently in use for the C3S products for those forecasting systems can be found within the information about the concept of nominal start date.

(3) Despite being produced in a lagged mode, the data from this forecasting system is currently encoded and provided in CDS as if all the members were initialized on the 1st.

(4) Due to the flexibility of the Met Office forecasting system, forecast failures on a given date are not usually recovered by re-running the missed forecasts at a later date, but by running more members with initial conditions of the day of recovery. Example: An incident affected the 22 August 2017 forecast so no members are available for that date. Instead, 4 members were initialised on 23 August 2017.

(5) Details of the complete list of start dates are provided in the description of CFSv2 system, section 6. Other relevant information.

(6) Details of the complete list of start dates are provided in the description of CPS3 system, section 6. Other relevant information.

(7) ECCC contribution, CanSIPSv3.0, is a multi-system composed of two independent forecasting systems.

(8) At present, no hindcast data is available for start dates before 1993.

Versioning of forecasting systems contributing to C3S


All C3S seasonal forecast data served through the CDS is currently held at ECMWF MARS archive, where data is stored in GRIB format. Due to that fact, the different forecasting systems of a given producing centre are labelled using the MARS-specific keyword "system" contained in each GRIB header as an integer number. For any data retrieval, the CDS will require that "system" keyword to be specified.

The use of the "system" keyword to match real-time forecasts with their relevant hindcasts is a critical element for a correct use of the C3S seasonal forecast data.

Details on how that label is assigned can be found in the following sections.

Systems producing their hindcasts as a fixed dataset

For these forecasting systems, a unique value of the keyword "system" is assigned trying to map as close as possible the version numbering used by the forecasting centres. Specifically:

Forecasting centreForecasting system nameCDS 'system' valueCDS 'model_id'(*)
ECMWF

System 44
SEAS55
51(a)

SEAS5-v20171101

Météo-FranceSystem 55
System 66

System6-v20170501

System 77

System7-v20190301

System 88

System8-v20210101

CMCCSPS33

CMCC-CM2-v20160423

SPS3.535

CMCC-CM2-v20191201

DWDGCFS2.02

GCFS2.0-v20171123

GCFS2.121

GCFS2.1-v20200320

NCEPCFSv22

CFSv2-v20110310

JMACPS22

cps2-v20150526

CPS33

cps3-v20220201

ECCCGEM-NEMO1

GEM-NEMO-v20190731

CanCM4i2

CanCM4i-v20190731

GEM5-NEMO3

GEM5-NEMO-v20211130

CanESM5.1p1bc4

CanESM5.1p1bc-v20240611

GEM5.2-NEMO5

GEM5.2-NEMO-v20240611

(*) This model_id tag is used internally in some parts of the CDS infrastructure to label the seasonal forecast data. In particular data which is archived on netCDF format will use this labelling. Currently this only applies to ocean variables contained in the seasonal-monthly-ocean dataset.
(a) 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)

Systems producing their hindcasts on-the-fly

Systems following this approach generate a new set of hindcasts close to the production of the real-time forecast for which those hindcasts are relevant. This production schedule approach enables these forecasting systems to implement updates and changes more frequently. But often the lifetime of a given version is longer than a year, and that would result in hindcast data for the same start dates being produced with exactly the same version of the forecasting system twice (or more times, if that version's lifetime ends up being longer than 2 years). To enable the distinction between hindcasts for the same hindcast start dates produced in those situations some form of sequential labelling would be needed.

Before March 2021

Following the data practices in EUROSIP, the predecessor of C3S seasonal forecast activity, the 'system' keyword was used as a numeric sequential label without any meaning related to the underlying forecasting system. In that sense, a given version of the forecasting system could span a few different values of the 'system' keyword as listed below.

The only producing centre following this approach in this period was the UK MetOffice, and the increments on the value of 'system' were introduced on the May nominal start date each year. Specifically:

Forecasting centreForecasting system nameReal-time forecast
nominal start dates
CDS 'system' valueCDS 'model_id' (*)
UK MetOfficeGloSea5-GC2September 2017 to April 201812

HadGEM3-GC2.0-v20150825

May 2018 to April 201913
GloSea5-GC2-LIMay 2019 to April 202014HadGEM3-GC2.0-v20190305
May 2020 to February 2021

15

(*) This model_id tag is used internally in some parts of the CDS infrastructure to label the seasonal forecast data. In particular data which is archived on netCDF format will use this labelling. Currently this only applies to ocean variables contained in the seasonal-monthly-ocean dataset.

After March 2021

With the start of operations of MetOffice GloSea6 forecasting system, a new numeric labelling paradigm has been introduced with two main aims: on one hand, to keep the incremental labelling when needed, and on the other hand, make more transparent and user-friendly the mapping between different versions of the forecasting system and that 'system' keyword.

Essentially, the value of the 'system' keyword for hindcast data produced on-the-fly (and their related real-time forecasts) would be assigned with the following approach: a three-digit number with the first digit being the version of the forecasting system; the second digit will be assigned to those changes in the forecasting system constituting minor revisions; and finally the last digit will start in 0 and will be updated incrementally each year if a new hindcast is going to be produced with the same version of the forecasting system (i.e. when the first two digits have not changed).

This is how this system labelling would have worked if applied to the previous versions of MetOffice seasonal forecast data

Forecasting centreForecasting system nameReal-time forecast
nominal start dates
CDS 'system' valueNEW 'system' value
UK MetOffice

GloSea5-GC2September 2017 to April 201812500
May 2018 to April 201913501
GloSea5-GC2-LIMay 2019 to April 202014510
May 2020 to February 202115511

Please note, this table has been put together just for illustrative purposes, and therefore the values listed in the column "NEW 'system' value" haven't been used.

The following table lists the values of 'system' keyword used in the CDS for on-the-fly hindcasts systems:

Forecasting centreForecasting system nameReal-time forecast
nominal start dates
CDS 'system' valueCDS 'model_id' (*)
UK MetOfficeGloSea6March 2021 to February 2022600HadGEM3-GC3.2-v20200929

March 2022 to February 2023601
March 2023 to February 2024602
From March 2024603

(*) This model_id tag is used internally in some parts of the CDS infrastructure to label the seasonal forecast data. In particular data which is archived on netCDF format will use this labelling. Currently this only applies to ocean variables contained in the seasonal-monthly-ocean dataset.

This document has been produced in the context of the Copernicus Climate Change Service (C3S).

The activities leading to these results have been contracted by the European Centre for Medium-Range Weather Forecasts, operator of C3S on behalf of the European Union (Delegation agreement signed on 11/11/2014). All information in this document is provided "as is" and no guarantee or warranty is given that the information is fit for any particular purpose.

The users thereof use the information at their sole risk and liability. For the avoidance of all doubt, the European Commission and the European Centre for Medium-Range Weather Forecasts have no liability in respect of this document, which is merely representing the author's view.