1. Forecast system version

Identifier code: Météo-France System 7

First operational forecast run: October 2019

2. Configuration of the forecast model

Is the model coupled to an ocean model?   Yes

Coupling frequency: 1 hour

2.1 Atmosphere and land surface



(land surface)

Horizontal resolution and gridTL359; 0.5° reduced Gauss grid
Atmosphere vertical resolution91 layers
Top of atmospheretop layer 1 Pa
Soil levels14 layers
Time step10 min

Detailed documentation:

ARPEGE: http://www.umr-cnrm.fr/IMG/pdf/arp62ca.july2017.pdf

SURFEX: http://www.umr-cnrm.fr/surfex//IMG/pdf/surfex_scidoc_v8.1.pdf

2.2 Ocean and cryosphere

Ocean modelNEMO v3.6
Horizontal resolution0.25° ORCA grid
Vertical resolution75 levels
Time step15 min
Sea ice modelGELATO v6
Sea ice model resolution0.25° ORCA grid
Sea ice model levels5
Wave modelNone
Wave model resolutionNA

Detailed documentation:

NEMO: NEMO documentation

GELATO: GELATO documentation

3. Initialization and initial condition (IC) perturbations

3.1 Atmosphere and land

Atmosphere initialization
Atmosphere IC perturbationsNoneNone

Land Initialization

Land IC perturbationsNoneNone
Soil moisture initializationERA5IFS
Snow initializationERA5IFS
Unperturbed control forecast?NANA

Detailed documentation: see ECMWF page

3.2 Ocean and cryosphere

Ocean initialization





Ocean IC perturbationsNoneNone
Unperturbed control forecast?NANA

Detailed documentation: https://www.mercator-ocean.fr/solutions-expertises/produits-references-mercator-ocean/

4. Model Uncertainties perturbations:

Model dynamics perturbationsYes
Model physics perturbationsNo

If there is a control forecast, is it perturbed?


Detailed documentation: Batté, L. and Déqué, M., 2016: Randomly correcting model errors in the ARPEGE-Climate v6. 1 component of CNRM-CM: applications for seasonal forecasts, Geoscientific Model Development,9, 2055-2076, doi:10.5194/gmd-9-2055-2016

5. Forecast system and hindcasts

Forecast frequencymonth
Forecast ensemble size51
Hindcast years1993-2016
Hindcast ensemble size25
On-the-fly or static hindcast set?static

6. Other relevant information

The forecast uses three start dates:

  • The penultimate Thursday of the previous month (25 members in the forecasts, 12 members in the hindcasts)
  • The last Thursday of the previous month (25 members in the forecasts, 12 members in the hindcasts)
  • the 1st of the month (1 member in the forecast/hindcast)

7. Where to find more information

Technical implementation details can be found in http://www.umr-cnrm.fr/IMG/pdf/system7-technical.pdf