So does a snow producing (as opposed to hail) cloud still contain supercooled water droplets or does the water vapour form directly into snow crystals?
I have not experienced airframe icing in these kinds of conditions, but in wet snow have experienced issues with induction icing, alternate air use was required.
Knowing that Bookworm has a PhD in this subject, he won't be asking any questions to which he doesn't know the answers 
I think flying in snow, under the cloudbase, is normally OK - except for the reduced vis.
But one cannot generally conduct a Eurocontrol-filed IFR flight like that. One has to file for say FL100, FL150, with a minimum that has any meaning of FL070, and that will take you above the cloudbase.
I don't know how snow forms but I've read that it can form by the crystallisation of freezing rain, so that would be a really great place to be (not).
What I don't know is how far above the cloudbase one would have to be to encounter the hazardous conditions. In the pic I posted, I guess the cloudbase was about 1000ft AMSL but one could not actually see it. So a VFR flight, trying to stay below the cloud whose base is not visible, is not a good idea, IMHO. One needs to retain the "IFR option" but that could take one into something nasty.
This one comes to mind.
Peter. That article talks about: pilot with PPL but no IR, severe-icing forcasted in CB clouds, aircraft not equipped with de-icing system. I don't think the fact that it was snowing was causing the accident. Or did I miss something in the article.
Yes; I don't think you will crash just because it's snowing - other than via an air intake blockage.
What I had in mind were the general conditions, including possibly structural icing.
His decisionmaking was also "interesting".
The point, I think, is that one could not climb up out of it because of structural icing and the layer from which a lot of snow will be falling is going to be fairly thick.
From my experience I would say that there is no direct relationship between the fact that it is snowing and the risk of icing when compared to flying in the same kind of winter conditions with no snow. A lot of times I fly in snow, there is no icing-buildup whatsoever and other times it is not snowing and I pickup ice. To me, the snow is just snow. I have compared the fact that is was going to snow with e.g. the icing risk forecasted by Sembach (http://ows.public.sembach.af.mil/index.cfm?section=Hazards) and did not see a direct correlation there as well. Of course, it is freezing cold and there are clouds, so there is a risk of ice, but the snow does not add something to that risk as far as I know of or as experienced.
Actually, when you fly at night through the snow, turn your landing lights on. That is a really magic experience.
I have never seen the stuff stick to the aircraft, but there is dry snow and there is wet snow…
Flying through snow is not an issue as such. It can reduce visibility a lot if you arrive at the airport while it is snowing. Flying through snow at night can be cool. Turn on your headlight and you feel like you are flying through space :-)
I wouldn’t recommend taking off in it as you will end up with contamination on the wings, but flying through it in VMC is unlikely to be a huge issue.
What would be the mechanism for it to stick? Presumably if it’s still snow, either it’s dry or the ambient temperature is above zero. It can collect through geometry (impact icing in intakes and gaps etc.) but it shouldn’t “stick” to surfaces.
I’d be more interested to know if anyone has had icing in a cloud from which dry snow is falling, or whether such a cloud is sufficiently glaciated that there’s no supercooled liquid water.
As AeroPlus says, it can look cool. I haven’t flown through falling snow for a while, but I remember it being like passing through a tunnel of shredded tissue paper!
