There are four main precipitation types, and the Philadelphia area can and does receive all types, sometimes all within a single storm. The four types of precipitation are rain, snow, sleet and ...

The new White Mountains Almanac explains how temperature and humidity determine snow crystal structure, influencing snow quality and winter conditions across western Maine.

Snow forms when atmospheric temperatures are cold enough for water vapor to freeze into ice crystals within clouds. An approaching arctic air wave is contributing to the current winter storm ...