_Scotch Mist._--(See _mist_.) _Scud._--Shreds or small detached masses of cloud moving rapidly below a rain cloud or other heavy clouds. _Sea Breeze._--(See _land and sea breezes_.) _Secondary._--A small cyclone developed, or tending to develop, on the border of a large one. _Sensible Temperature._--The temperature felt at the surface of the human body; formerly identified, by some authorities, with the temperature indicated by the wet-bulb thermometer. _Silence, Areas, Zones, or Regions of._--Regions within which a sound is not heard, though heard in regions more distant from the source. _Silver Thaw._--A term variously applied to rime, glaze, and a thin coating of ice deposited on cold objects by a damp wind. _Simoom._--An intensely hot and dry wind of Asian and African deserts; often described as a sand storm or dust storm, but certain authorities state that the typical simoom is free from sand or dust. _Sirocco._--A name applied to various types of warm wind in the Mediterranean region. Some of these siroccos are foehns. The term is also used as the generic name for winds blowing from a warm region toward an area of low pressure in a normally colder region. _Sleet._--1. Frozen or partly frozen rain; frozen raindrops in the form of particles of clear ice. 2. Snow and rain falling together. (Other definitions have been proposed and the proper technical application of this term is still a subject of controversy. In popular and engineering use the word is often applied to a coating of glaze on trees, wires, rails, etc.) _Snow Bin._--A large receptacle for collecting the snowfall of an entire winter, or other long period, for measurement at one time. _Snow Garland._--An elongated mass of snow suspended at the ends and sagging in the middle. _Snow Mushroom._--An overhanging cap of snow resting on a tree stump, post, or the like. _Snow Roller._--A mass of snow rolled by the wind; generally muff-shaped. _Snow Sampler._--A device for collecting a sample of snow, cut vertically through a snowfield, for the purpose of determining the depth and density of the snow. _Snow Survey._--A measurement of the total amount of snow lying over a particular area, especially with a view to determining the total amount of water it will yield, when melted, for purposes of irrigation, etc. _Soft Hail._--Graupel. _Sounding Balloon._--A free, unmanned balloon carrying a set of self-registering meteorological instruments. _Specter of the Brocken._--The shadow of an observer and of objects in his immediate vicinity cast upon a cloud or fog bank; sometimes attended by a series of colored rings, called the _glory_ or _Brocken-bow_.