weather discrippancy

After several observation I noticed discrippancy when there's f.e a METAR as follows:

EHAM 290925Z 16005KT 0200 R18C/0550N R27/0325N R18R/0275N R06/0325N FZFG VV001 M02/M02 Q1040

It seems when rvr's are reported the weather is not correct translated into the flightsim
In the above situation temp and qnh are standard set to 15 deg and 1013

My setup FS9 and PMDG737NG

FSrealwx is communicating through FSUIPC but the same problem occurs when I use your WX bridge

Any idea why this happens?

Marcel