Precipitation Precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and "precipitates". Thus, fog and mist are not precipitation but suspensions, because the water vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with
April shower April shower In the United Kingdom and Ireland, an April shower is rain during the month of April. One of the major causes of the often heavy downpours is the position of the jet stream. In early spring, the jet stream starts to move northwards, allowing large depressions to bring strong winds and rain in from the Atlantic. In one day the weather can change from springtime sunshine to winter sleet and snow. The track of these depressions can often be across Ireland and Scotland bringing bands of rain followed by heavy showers (often of hail or snow) and strong