...
Table 5 - Root Mean Square Error (rmse)
...
Definition
...
rmse of O-B values over a layer
...
Calculation
...
For each observed variable, the rmse is computed based on valid data for every station.
...
Valid data
...
Bias and std not NULL.
...
Minimum required valid data
...
2 valid value.
...
Math expression
...
Note that quality indicators are applied only to the measured quantities whose O-B departures are available in the NWP monitoring reports, i.e. the ones whose model equivalent is available from the NWP assimilation system (see sections 2.1 and 2.2). Therefore, if the O-B departures are missing because the model background is not calculated in a particular NWP assimilation (e.g., not all centres compute O-B departures for observations they do not use in assimilation) the quality indicator will not be calculated and the station will not show up on the quality map. This is why some stations appear in the availability map, but not in the quality map.
...