A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

The standard deviation of a sufficiently large number of measurements of the same quantity by the same instrument or method. The non-correctable part of the inaccuracy of an instrument, it represents the limit of measurement precision. The uncertainty of ...

Electromagnetic radiation lying in the wavelength interval between 0.8 micron and I millimeter. At the lower limit of this interval, the infrared radiation spectrum is bounded by visible radiation, while on its upper limit it is bounded by microwave radia ...

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

Old snow that has become granular and compacted as a result of melting and refreezing.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.