| name | surface air relative humidity | Abbreviation | rh | Unit | % |
| Definition | The ratio of the partial pressure of water vapour to the equilibrium vapour pressure of water at the same temperature near the surface. |
| Validity | instantaneous |
| Comment | Please note that the specific height level above ground might vary from one Centre to another. The scaled value of first fixed surface given below is the one in usage at ECMWF. |
...
| Level | ||
|---|---|---|
| Type of first fixed surface | 103 | specified height level above ground (m) |
| Scale factor of first fixed surface | 0 | |
| Scaled value of first fixed surface | 2 | 2m (might vary from one centre to another) |
| Type of second fixed surface | all bits to 1 | missing |
| Scale factor of second fixed surface | all bits to 1 | missing |
| Scaled value of second fixed surface | all bits to 1 | missing |