WeatherTalk: Making snow from boiling water
This is essentially how snowflakes form in a cloud.
Many of us have seen the magic of tossing a pan of boiling water into the air in 20 below zero cold in which the boiling water instantly turns into snow. This works in very cold conditions because very cold air has an extremely limited capacity for water vapor. The container of boiling water is, naturally, in a state of producing water vapor. That is precisely what boiling water does.
As this boiling water is sprayed into the frigid air, the water in the container is spread out into smaller and smaller blobs, resulting in more surface area of boiling water, which produces more water vapor. But the cold air has no room for it, so the vapor is forced to form into much denser ice crystals. This is essentially how snowflakes form in a cloud, although the in-cloud snow growth process is considerably slower and less dramatic.