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... :(