The European Centre for Medium-Range Weather Forecasting (ECMWF) Operational Atmospheric Model Data Archive

The Operational Data Sets provide access to most of the data from the
atmospheric model archived at ECMWF. These archives have a higher time
and space resolution and contain all parameters.

They should only be used where high resolution is essential; in this
respect they are particularly suited for use in conjunction with case
studies and as initial conditions for high resolution models.

These data sets contain data at the resolution of the data
assimilation and forecast system in operational use at ECMWF. Since
the resolution and internal representation of the archive may vary
according to changes in ECMWF's operational practice, data services
associated with these data sets include the provision of interpolation
to requested resolutions and representation forms.

This archive includes analysis, first-guess (6-hour forecasts, 4 times
per day) and forecast data. All data are available on the surface,
pressure levels and model levels.

Thirteen data sets are separately supported:

- Surface analysis
- Pressure level analysis
- Model level analysis
- Isentropic level analysis
- Potential vorticity level analysis
- Surface first guess
- Pressure level first guess
- Model level first guess
- Surface forecast
- Pressure level forecast
- Model level forecast
- Isentropic level forecast
- Potential vorticity level forecast

ECMWF Operational Atmospheric Model Data Sets:
"http://apps.ecmwf.int/archive-catalogue/?class=od&stream=oper"

[Summary extracted from the ECMWF home page]