Precipitation is any form of water that falls to the earth’s surface. This includes snow, rain, sleet, freezing rain, and hail.
Precipitation is generated in clouds. When water vapor droplets in clouds become so large that updrafts within the clouds can no longer support them, the water will fall to the earth under the force of gravity.
Precipitation is needed to replenish water to the earth. Without precipitation, this planet would be an enormous desert. The amount and duration of precipitation events affect both water level and water quality within an estuary. Precipitation supplies freshwater to estuaries, which is an important source of dissolved oxygen and nutrients. Droughts lower the freshwater input to estuaries and the water levels of inland lakes. Lake levels influence water drainage and circulation patterns in freshwater estuaries.
Precipitation is typically reported in millimeters or inches of liquid precipitation. This amount is typically added over a certain period of time, such as inches per day.
Precipitation can be measured in a numerous ways. One precipitation measuring instrument is known as a “tipping-bucket rain gauge.” A tipping bucket rain gage uses a small cup that fills with precipitation. When the cup is full, it will tip and empty. A counter tracks how many times the cup tips, and after a certain time interval, this number is converted to a precipitation measurement in millimeters. Heated tipping bucket rain gauges allow the measurement of snow and sleet.