Any condensed form of water--larger than a single water molecule--that is falling or suspended in the atmosphere; some examples of hydrometeors are snow, fog, cloud or rain. When these particles reach the size of 10-20 micrometers, available water is depleted and a stable cloud is formed. [Journal of Geophysical Research. Atmospheres; v 96; p 20809; 1991.] [Nuclear Instruments and Methods in Physics Research; v 79; p 397; 1993.]