Description of the upgrade

The IFS Cycle 49r1, will bring major changes to the IFS model and data assimilation system, including among many others:

• assimilation of 2m temperature observations, 
• Land-surface model updates,
• increased resolution and soft-recentering of the ensemble of data assimilations (EDA)  and
• activation of the stochastically perturbed parameterisations (SPP) model uncertainty scheme in all ensemble configurations. 

Extended-range forecast will change name to sub-seasonal range forecast. This name change will be gradually implemented in the documentation.

The re-forecast systems for medium and extended range will see the change in frequency, both will run over past 20 years, on the fixed days of the month: 

• medium range every four days: 1/5/9/13/17/21/25/29 (excluding 29 February)
• extended range every two days: 1/3/5/7/9/11/13/15/17/19/21/23/25/27/29/31 (excluding 29 February)

In IFS Cycle 49r1, HRES and the ENS control forecast become scientifically and computationally identical and both are run for 15-days at 00 UTC and 12 UTC, and 6 days at 06 UTC and 18 UTC. The superfluous ENS control forecast will be stopped in a future IFS upgrade, and the data stream currently known as HRES will become known as the “control” forecast.

From IFS Cycle 49r1 the wave model will be run on the same octahedral reduced gaussian grid as the atmospheric model, simplifying the data exchange between the two systems. Consequently the resolution of the wave model will increase to ~9km (O1280) in the medium range and ~36 km (O320) in the sub-seasonal range. With higher resolution, the wave model is better able to capture the atmospheric forcing, and details of the coastal conditions are generally better represented. The wave model will also run for 15-days at 00 UTC and 12 UTC, and for 6 days at 06 UTC and 18 UTC.

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

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

#IFS49r1 #newfcsystem @ECMWF

News

Timeline of the implementation

Datasets affected

• HRES (day 1-15)

• ENS (day 1-15)

• ENS sub-seasonal (previously 'extended') (day 1-46)

• HRES-WAM (day 1-15)

• ENS-WAM (day 1-15)

• ENS-WAM sub-seasonal (previously 'extended') (day 1-46)

Webinars

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