Description of the upgrade

The IFS Cycle 50r1, will bring  major changes to the IFS model and data assimilation system, including among many others:

  • New ocean and sea ice models  based on NEMO4-SI 3
  • Updates of the wave model including: n ew wave interaction with sea ice and ocean currents and revised wave model bathymetry
  • Modified Stochastically Perturbed Parametrisation (SPP) configuration to reduce 10-metre wind spread in the ensemble
  • New ocean and sea ice ensemble analysis system & outer loop coupling of ocean/sea-ice
  • Weak constraint formulation extended to the boundary layer allowing the i ncreased use of T2m observations 

After making the high-resolution forecast (HRES) and 'control' member of medium range ensemble forecast (ENS control) identical in IFS Cycle 49r1, , with this model upgrade we will stop producing the current ENS control, and the data stream that was formerly called the HRES will be called ENS control instead.

More detailed information will be made available in the coming weeks.

For any questions, please contact us via the ECMWF Support Portal.

#IFS50r1 #newfcsystem @ECMWF

News

  Initial announcement.

Resources

Webinars

Introduction to Cycle 50r1

Verification, products and technical aspects

Data access and format, testing and practicalities

15 September 2025,
15:45 UTC/16:45 BST/17:45 CEST

Register here:
https://events.ecmwf.int/event/502/

If you're attending UEF2025, join the presentation in-person in the Tecnopolo di Bologna. 

Coming soon! Watch this space!

Coming soon! Watch this space!

References

For any questions, please contact us via the ECMWF Support Portal .

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