February 2nd. In American folklore, a day that is popularly supposed to provide the key to the weather for the remainder of the winter. Specifically, if the ground-hog upon emerging from its hole casts a shadow, it will return underground, thereby forebod ...

A method of winds aloft observation in which the elevation and azimuth angles of a theodolite are read while visually tracking a pilot balloon. Balloon height data is estimated from assumed balloon ascension rates.

An instrument for the measurement of the net flux of downward and upward total (solar and terrestrial) radiation through a horizontal surface.

See bimetallic thermometer.

Pertaining to rain, or more broadly, to precipitation.

The portion of the precipitation on the land which ultimately reaches the streams. especially the water from rain or melted snow that flows over the surface.

Not a linear function of the relevant variables.

Automated Surface Observing System. A network of instrumented weather stations deployed primarily by the National Weather Service to make weather observations without operator involvement.

The elevation of the water surface in a stream as measured by a river gauge with reference to some arbitrarily selected zero datum.

Programs or instructions which are stored in readonly memory.

Radiation with wavelengths greater than 4 microns. (In meteorology, same as infrared radiation.)

A radiosonde equipped to measure temperature only.

A measure of luminous flux remaining in a light beam after it has passed through a specified distance of the atmosphere.

The array of indicating marks and figure in relation to which the position of an index is observed, i.e. a scale plate on a recorder.

Wind with a speed between 4 and 27 knots (4 and 31 mph); Beaufort scale numbers 2 through 6.

A liquid-in-glass or liquid-in-metal thermometer using mercury as the liquid.

The amount of precipitation captured by a rain gauge.

A unit of luminance (or brightness) equal to 1/6 candles per square centimeter.

Part of a computer word that has meaning in itself, often, a byte.

See hydrologic accounting.