Temp for snow formation

[toadster920]

John,

Does it have to be 32 degrees or below for snow to form? I have heard that snow actually has a better chance of forming when it is about 34 degrees.

Thanks,
Todd

 

[admin]

Todd.

The temp HAS to be at least 32 degrees in order for water to freeze. In fact because of the way water vapor works, it typically has to be well below freezing for the water vapor to become an ice crystal. Keep in mind this is for where the snowflake is formed, generally 3,000-15,000 feet above the ground.

It is possible for snow to fall when the surface temps are above 32. In fact I have seen it snow when surface temps are above 40. Surface temps above 32 do not increase the chance of snow forming though. It basically has to do with there being enough moisture and lift to condense the vapor. It also has to be cold enough for the vapor to turn into an ice crystal and then temps need to be cold enough to have the ice crystal not melt all the way to the surface.

-John