One old gliding instructor and top-level competition glider pilot told me of gliding in the Alps and seeing the snowflakes go upwards.
This surprised me because snowflakes seem to fall at roughly 1m/sec i.e. around 200fpm, and I would think a decent glider would be descending at less than that.
Does it make sense?
Maybe it does, since a typical SEP glides at around 10:1 and at about 1000fpm, and best gliders are around 50:1 which would be around 200fpm, assuming similar speeds.
In thermals or any (orographic) lifting the snow flakes climb better than a glider. And there you might see snow flakes climb. Is it possible that he was referring to this?
Gliders generally glide with a sink rate of around 150 fpm at best L over D, and most gliders have a sink rate round about this value right from low performance trainers like the Ka-8 all the way up to high performance glass.
The difference is that low performance gliders will quickly get a much higher sink rate as you go above best L over D (so get up to 75kt in a Ka-8 and you’re kind of staring at the ground), but high performance gliders will still have a low sink rate at quite high speeds (e.g. in a Discus, you can be doing 90 kt without much of a sink rate).
Gliders certainly do not fly at best L/D speed all the time. When penetrating headwinds or flying through downdrafts or just flying transit between updrafts/thermals they will fly a lot faster with a much higher corresponding sink rate,
.
According to metoffice.gov.uk snow typically falls at 1 to 4 mph with 1.5 mph being the most common.
1 mph is around 90 fpm and not many gliders are capably of a vertical speed that low.
So he was just sinking faster than the snowflakes or what? I can do that even without a plane. Just drop me out of one.
According to metoffice.gov.uk snow typically falls at 1 to 4 mph with 1.5 mph being the most common.
1 mph is around 90 fpm and not many gliders are capably of a vertical speed that low.
That must be the reason for that report. Interesting. Of course in powered flight in snow we never see that 
My experience is that snow flakes always come from the front at about 10 deg from above. No exception. And independent of the vertical speed of the glider. We fly a lot in snow showers here in Germany during spring. They are very welcome. They offer strong thermals and do not suppress the further thermal development, contrary to normal rain showers. Oftern the snow does not reach the ground. The only danger is visibility. It can be reduced dramatically. But nowadays we have AH or syn. vision. BTW: The strength of snow fall is defined by visibility.
I remember seeing snow flow upward when sitting at the Windows of the World bar on the top floor of the World Trade Center, due to updrafts between the buildings. (I’m not talking about the chemical type of “snow”, although that also seemed to flow upward – in people’s noses).
Your horizontal speed is also so high compared to the snow’s vertical speed, that the snow’s actual behaviour (whether it’s rising or falling) will almost make no difference.
I flew thorough snow in my old Cessna 140, in that plane it appeared to be coming from a few degrees below the nose and going slightly upwards, while in level flight.
