Here in Prague (LKPR) today we have beautiful weather. Sun is shining, clear blue sky, but quite enough snow on the ground and strong wind. So the metar contains DRSN - drifting snow. But what does the ASA engine do? DRSN = Moderate snow, so there's terrible blizzard, slippery runways and overcast. Drifting snow means it remains below 8 feet (2 m) so why it's decoded as Moderate snow? It's totally something else. Yes, it's not so usual weather but today I had to switch ASA off because it was as real as blizzard in June in California... :(

I suppose this is because FSX can't do drifting snow.

Sorry tmx but we are limited by the programming in FS. So we do need to take some of the conditions that real world data gives us and convert it into something that FS is able to use. Another example: if you ever see a tornado report in a METAR don't think that ASA or FS will show that either. Also, there is no such thing as a slippery runway in FS. Sorry you had to switch off ASA over this.