Jasmine: My name is Jasmine.
Chrissy: And I'm Chrissy.
Jasmine: We're from NIU STEAM and...
Chrissy: This is The Sound of Science on WNIJ. Snowfall can happen at any time, but sometimes it seems that it falls more often at night. It's more about perception and atmospheric conditions than actual timing.
Jasmine: One of the biggest reasons that we perceive that it snows more often at night is how quiet and bright a new snowfall seems. Unlike rain, when snow accumulates there's good deal of air pocketed between the tiny crystals. The air pockets act as an insulator because they absorb and scatter sound waves. Ambient noise like trains and traffic are more noticeable at night because public hustle and bustle is absent. When that ambient noise is gone as well it's very noticeable.
Chrissy: Jasmine just described snow as tiny crystals and it is the crystalline structure that makes snow highly reflective. Even when there is a sliver of a Moon that we don't really notice, there is enough light to be amplified by the snowflakes. Street lights, porch lights, and distant city lights are also reflected in many directions to brighten the night. This phenomenon is especially noticeable on overcast nights when the clouds reflect the light back down to the surface of the Earth.
Jasmine: An atmospheric reason that makes it seem like it snows more at night, is that temperatures are typically colder because the Sun isn't warming the surface. This helps keep the snow from melting and allows more moisture to condense into snowflakes rather than rain.
Chrissy: Finally, during the day, the Sun can warm the atmosphere even if it's cloudy, sometimes preventing snow from forming or causing it to melt as it falls. Snow virga occurs when snowflakes fall from a cloud but evaporate before they hit the ground, At night, without solar heating, snow is more likely to reach the ground intact.
Jasmine: You have been listening to The Sound of Science on WNIJ, where you learn something new every day.
