1. Forecast system version

System name: Météo-France system 5

First operational forecast run: July 2016

2. Configuration of the forecast model

Is it a coupled model ?  yes

Coupling frequency: day

2.1 Atmosphere and land surface


ARPEGE v6.1 (atmosphere)

SURFEX 7.3 (land surface)

Horizontal resolution and gridTL255: 0.7° Gauss reduced grid
Atmosphere vertical resolution91 layers
Top of atmospheretop layer: 0.2 Pa
Soil levels3 layers (top, root, total) geographically dependent
Time step15 min

Detailed documentation: ARPEGE documentation

Land surface model: SURFEX 7.3

2.2 Ocean and cryosphere

Ocean model

NEMO v3.2

Horizontal resolution1° ORCA grid
Vertical resolution42 levels
Time step1 hour
Sea ice modelGELATO v5
Sea ice model resolution1° ORCA grid
Sea ice model levels9 (+1 for snow)
Wave modelNone
Wave model resolutionNA

Detailed documentation: NEMO documentation

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 initializationERA-interimIFS
Snow initializationERA-interimIFS
Unperturbed control forecast?NANA

Detailed documentation: see ECMWF page

3.2 Ocean and cryosphere

Ocean initializationGLORYS2V2Mercator-Ocean
Ocean IC perturbationsNoneNone
Unperturbed control forecast?NANA

Detailed documentation: Mercator-Ocean initialization

4. Model uncertainties perturbations:

Model dynamics perturbationsYes
Model physics perturbationsNo

If there is a control forecast, is it perturbed?


Details in: 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, in line, doi:10.5194/gmd-9-2055-2016

5. Forecast system and hindcasts

Forecast frequencymonth
Forecast ensemble size51
Hindcast years1991-2014
Hindcast ensemble size15
On-the-fly or static hindcast set?static

6. Other relevant information

Before getting an operational status in July 2016, the forecasts had been produced since January 2015.

The hindcast/forecast ocean initial conditions are calculated with Mercator-Ocean PSI2G3R3 software. Before 1993, the ocean initial conditions come from ECMWF NEMOVAR reanalysis.

The forecast uses two start dates:

  • The first Wednesday falling between the 12th and the 18th of the previous month (25 members)
  • The following Wednesday (26 members)

The hindcast uses only the latter date (15 members).

7. Where to find more information

Technical implementation details can be found here.