In the coming months a couple of system upgrades are expected from the seasonal forecast providers to C3S.
-
Japan Meteorological Agency (JMA)
- January 2026 has been the last forecast release produced using the current JMA seasonal forecast system CPS3
- A new forecast system, CPS4, will be introduced in operations by JMA on 22/Jan/2026. At the time of this announcement it is not yet possible to confirm whether this new system will be integrated in C3S in time for February 2026 or later in the year.
- Additional details about this new forecast system and its availability on the CDS will be communicated in this forum as soon as they become available.
-
UK MetOffice
- A new version of the MetOffice forecast system, GloSea6-GC5.1, will be soon introduced in operations. April 2026 will be the first C3S seasonal forecast release including this new system.
- At least on 10/March/2026 the hindcast data for April start dates will be published on the CDS
- This forecast system will use the CDS API keyword
system=610 - Additional details about this system will be soon published in the CDS documentation for the C3S seasonal forecast datasets.
- A new version of the MetOffice forecast system, GloSea6-GC5.1, will be soon introduced in operations. April 2026 will be the first C3S seasonal forecast release including this new system.