Real-time forecasts

Release dates:
ECMWF:  on the 6th of each month at 12UTC
All other forecast systems:  on the 10th of each month at 12UTC

Nominal start dates

ECMWF

Météo-France

Met Office(a)DWDCMCCNCEPJMAECCC
System 4SEAS5
(system=5)
SEAS5
(system=51)
System 5System 6System7System8system=12system=13system=14system=15GloSea6
(system=600)
GloSea6
(system=601)
GloSea6
(system=602)
GloSea6
(system=603)
GCFS2.0GCFS2.1SPSv3SPSv3.5CFSv2CPS2CPS3GEM-NEMOCanCM4iGEM5-NEMOCanESM5.1p1bcGEM5.2-NEMO
September 2017 - October 2017(tick)(error)(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(error)(error) (error)(error)(error)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
November 2017 - January 2018(error)(tick)(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(error)(error) (error)(error)(error)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
February 2018 - April 2018(error)(tick)(error)(tick)(error)(error)(error)(tick)(1)(error)(error)(error)(error)(error)(error)(error) (error)(error)(error)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
May 2018 - October 2018(error)(tick)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(error) (error)(error)(error)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
November 2018 - April 2019(error)(tick)(error)(error)(tick)(error)(error)(error)(tick)(3)(error)(error)(error)(error)(error)(error) (tick)(error)(tick)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
May 2019 - September 2019(error)(tick)(error)(error)(tick)(error)(error)(error)(error)(tick)(2)(error)(error)(error)(error)(error) (tick)(error)(tick)(error)(error)(error)(error)(error)(error)(error)(error) (error) 
October 2019 - April 2020(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error) (tick)(error)(tick)(error)(tick)(error)(error)(error)(error)(error)(error) (error) 
May 2020 - September 2020(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error) (tick)(error)(tick)(error)(tick)(error)(error)(error)(error)(error)(error) (error) 
October 2020(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error) (tick)(error)(error)(tick)(tick)(tick)(error)(error)(error)(error)(error) (error) 
November 2020 -  February 2021(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error) (error)(tick)(error)(tick)(tick)(tick)(error)(error)(error)(error)(error) (error) 
March 2021 - April 2021(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(tick)(4)(error)(error)(error) (error)(tick)(error)(tick)(tick)(tick)(error)(error)(error)(error)(error) (error) 
May 2021 - June 2021(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(tick)(error)(error)(error) (error)(tick)(error)(tick)(tick)(tick)(error)(tick)(tick)(error)(error) (error) 
July 2021 - November 2021(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error) (error)(tick)(error)(tick)(tick)(tick)(error)(tick)(tick)(error)(error) (error) 
December 2021 - January 2022(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error) (error)(tick)(error)(tick)(tick)(tick)(error)(error)(tick)(tick)(error) (error) 
February 2022(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error) (error)(tick)(error)(tick)(tick)(error)(tick)(error)(tick)(tick)(error) (error) 
March 2022 - October 2022(error)(tick)(error)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(tick)(error)(error) (error)(tick)(error)(tick)(tick)(error)(tick)(error)(tick)(tick)(error) (error) 
November 2022 - February 2023(error)(error)(tick)(5)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(tick)(error)(error) (error)(tick)(error)(tick)(tick)(error)(tick)(error)(tick)(tick)(error) (error) 
March 2023(6) - February 2024(error)(error)(tick)(error)(error)(error)(tick)(error)(error)(error)(error)(error)(error)(tick)(error) (error)(tick)(error)(tick)(tick)(error)(tick)(error)(tick)(tick)(error) (error) 
March 2024 - June 2024(error) (error) (tick) (error) (error) (error) (tick) (error) (error) (error) (error) (error) (error) (error) (tick) (error) (tick) (error) (tick) (tick) (error) (tick) (error) (tick) (tick) (error) (error) 
From July 2024(error) (error) (tick) (error) (error) (error) (tick) (error) (error) (error) (error) (error) (error) (error) (tick) (error) (tick) (error) (tick) (tick) (error) (tick) (error) (error) (error) (tick) (tick) 

(1) 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) Upgrade to model version: GloSea5-GC2-LI. Data deficiencies fixed, see known issue D9.
(3) Hindcast period is extended to 2016.
(4) With the introduction of GloSea6, the labelling of the system keyword for systems with hindcasts produced on-the-fly was changed. More details here.
(5) 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)
(6) From March 2023 a dataset with ocean variables is available from the CDS catalogue (see details on availability here).

Hindcasts

Nominal start dateECMWFMétéo-FranceMet Office(a)DWDCMCCNCEPJMAECCCNominal start date
System 4SEAS5
(system=5)
SEAS5 
(system=51)(b)
System 5System 6System 7System 8system=12system=13system=14system=15GloSea6
(system=600)

GloSea6 (system=601)

GloSea6

(system=602)

GloSea6

(system=603)

GCFS2.0GCFS2.1SPSv3SPSv3.5CFSv2CPS2CPS3GEM-NEMOCanCM4iGEM5-NEMOCanESM5.1p1bcGEM5.2-NEMO
January(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(c)(tick)(c)(tick)(c)(tick)(c)(tick)(c)(tick)(c)(tick) (c)(error) (c)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(error) (error) January
February(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (error) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(error) (error) February
March(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(error) (error) March
April(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(error) (error) April
May(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error) (error) May
June(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error) (error) June
July(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)July
August(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) *(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick)August
September(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick) September
October(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) *(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick) (tick) October
November(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error) (error) November
December(error)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)
(tick)(tick)(tick)(tick)(tick)(tick)(error)(tick)(tick)(error) (error) 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)

NOTE

(tick) *
Currently these data are temporarily only available using CDS API and may appear as (partially or totally) unavailable in the CDS interactive forms.

NOTE

Detailed information about the dates available as hindcasts or real-time forecasts for each individual forecast system can be found in Start dates available in the CDS per forecast system


Nominal Start Dates

For systems with lagged ensembles having multiple start dates, the "nominal" start date is assigned as follows:

Météo-France (all systems):

  • Forecasts/Hindcasts: nominal month M includes the members initialised in the last weeks of month M-1 and on the 1st of month M

NOTE: Even though the different members of all Météo-France forecasting system ensembles are initialized using a lagged approach, the real start dates are not revealed to the users, so all members are encoded as if they were initialized on the 1st of the month

UK MetOffice (all systems):

  • Forecasts: nominal month M includes the members initialised on the 1st of month M and all available members with start dates back to, and including, the 2nd of month M-1
    • Note that even though just the most recent 50 members are used for C3S products, the complete set of members are available through the CDS
  • Hindcasts: nominal month M includes the members initialised on the 1st of month M and on the 25th, 17th and 9th of month M-1

NCEP:

  • Forecasts: nominal month M includes the members initialised on the 1st of month M and all available members with start dates back to, and including, the 2nd of month M-1
    • Note that even though just the most recent 52 members are used for C3S products, the complete set of members are available through the CDS
  • Hindcasts: nominal month M includes the members initialised on the 1st of month M (if available) and on all start days from month M-1 except the 1st (see table below)
Nominal start monthDates used for C3S productsAdditionally available dates
JANUARY

1 January; 27, 22 and 17 December

12, 7 and 2 December
FEBRUARY31, 26, 21 and 16 January11 and 6 January
MARCH25, 20, 15 and 10 February5 February
APRIL1 April; 27, 22 and 17 March12, 7 and 2 March
MAY1 May; 26, 21 and 16 April11 and 6 April
JUNE31, 26, 21 and 16 May11 and 6 May
JULY30, 25, 20 and 15 June10 and 5 June
AUGUST30, 25, 20 and 15 July10 and 5 July
SEPTEMBER29, 24, 19 and 14 August9 and 4 August
OCTOBER28, 23, 18 and 13 September8 and 3 September
NOVEMBER28, 23, 18 and 13 October8 and 3 October
DECEMBER27, 22, 17 and 12 November7 and 2 November

JMA:

  • Forecasts: nominal month M includes the members initialised on the 1st of month M (if available) and on all start days from month M-1 except the 1st
    • Note that even though only a subset using the most recent members is used for C3S products, the complete set of members is available through the CDS
      • For CPS2 the subset includes 52 members (4 start dates)
      • For CPS3 the subset includes 55 members (11 start dates)
  • Hindcasts: nominal month M includes the members initialised on the 2 available start dates from month M-1

See details about available dates from JMA at section 6 (Other relevant information) of the forecasting system description.


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.