Icing in a snow producing cloud

Brian Z

Well-Known Member
Assuming a standard lapse rate and the ground is below freezing, if a cloud is producing dry snow would it produce icing if flown into? My first thought is no as the moisture must be frozen to produce the snow.
 
My first thought is no as the moisture must be frozen to produce the snow.

I wouldn't draw that conclusion. All you know is that *some* moisture is frozen. More than likely, you have a mixture of frozen and supercooled liquid water in the cloud.
 
Assuming a standard lapse rate and the ground is below freezing, if a cloud is producing dry snow would it produce icing if flown into? My first thought is no as the moisture must be frozen to produce the snow.


Sometimes. Don't count on it though. I've always gotten the worst icing up at the top of the cloud, and in clouds that were slightly warmer than the air below them.
 
This is going to sound really dumb but can you get ice flying through snow? Not in the clouds that are producing the snow, but just the snow itself.
 
You can get icing in ANY form of visible moisuture. There is a form of icing known as "impact snow."

Yep, have experienced it in flight, and more commonly in my car during the winter. If the conditions are just right, you can get a thick rapidly accumulating layer on the leading edges of your mirrors, headlamps and front spoiler/bumper. Strange stuff....
 
You can get icing in ANY form of visible moisuture. There is a form of icing known as "impact snow."

Yup there is. I got that on my way driving to florida in a large snow storm. It froze on the front of my car and it then broke off and hit my left mirror and took off a big piece of paint.

As for the OP. How does the precip form in a cloud? That might answer your questions for icing in a snow producing cloud.
 
As for the OP. How does the precip form in a cloud? That might answer your questions for icing in a snow producing cloud.

Yep, I understand that. I was just wondering if it would be safe to assume(i use that word lightly) that the moisture would be frozen or just supercooled waiting for something to freeze to.
 
I used to fly freight nightly in light twins in Wisconsin and Minnesota without ever climbing above 6000'...so I've observed a lot of different icing conditions.

I used to give a sigh of relief when snow showers began hitting the windscreen...because I pretty much knew that ice accumulation was not going to occur during the snow shower. I can't say ice never accumulates during snow...but in a few thousand hours of beating around in those conditions without adequate ice protection capability...I can tell you that my observations have been that ice does not accumulate in a snow shower.
 
You can get icing in ANY form of visible moisuture. There is a form of icing known as "impact snow."

:yeahthat:

If your airplane surface is subzero temps it will probably produce ice, unless it's ice crystals( but snow is not considered ice crystals).
 
This is going to sound really dumb but can you get ice flying through snow? Not in the clouds that are producing the snow, but just the snow itself.
It's not really dumb.

It depends. That's the problem.

For example, how "snowy" is the snow? Is it cold and dry, the kind that will blow off before they stick to anything or large wet flakes that are heavy in water (perhaps supercooled water) content and "splash" when they hit?

Snow is like any other icing topic. What will happen is based on a number of variables and the more knowledge you have the better chance you have of making the right decision.
 
The thing I find hardest at night is to determine whether I'm in a snow shower only or in a cloud that's producing snow.

If I'm just in the snow, I don't worry too much. Maybe a little "impact snow", but nothing too severe. If it's in a cloud that's producing snow, I've seen negative icing to moderate icing.

-mini

PS
Along that topic. Anyone here fly the 727 that reported severe icing about 10 N of ILN last Monday night? Just wondering what y'all saw out there. I was on top by the time I got to that area, but it did have me concerned for a little bit.
 
Flew in snow producing clouds yesterday and I got some icing, first icing experience. Since I fly in the Northeast I am sure it will not be the last time.
 
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