All our friends know that we came to Latvia this year with really huge hopes of seeing real snow for the first time in our lives. Well, snow hasn't come yet, but something else made us jump with joy one morning - frost. When we woke up and looked outside, we couldn't believe our eyes - all the grass was white! At first, we got so excited, thinking that it was snow, but then mamma calmed us down saying that it's only frost. Nevertheless, we couldn't waste any time (what if the sun comes out and melts it?) and jumped right from our pajamas into warm jackets and were out of home for checking out the frost even before eating breakfast. When mamma called us home for breakfast, we brought for her some leaves with thick layer of frost on them. Even the cars parked outside our aparment building were covered by frost.
Later, we did some search online to find out, how frost gets made. We found this really neat site, which gave this explanation:
Have you ever heard of something called “water vapor”? Water vapor refers to water, when it’s in the form of a gas, instead of in the form of a liquid (like drinking water) or a solid (like ice cubes). It might be a little hard to understand, but it plays a big role in our weather! One thing that happens when water vapor freezes is that snowflakes can form, but another thing that can happen is frost! Frost refers to the white or clear ice crystals that cover surfaces such as plant leaves, windows, sidewalks, and more! Unlike snow, which forms in the air and then falls from the sky, frost grows closer to the ground on cold surfaces. Frost is the result of water vapor in the atmosphere that freezes directly into its solid state (ice) without first passing through its liquid state (water). Neat! (
http://www.whyzz.com/what-is-frost )