A fabric cone attached to a metal ring and used to indicate wind direction. often at airfields.

A radiosonde whose carrier wave is switched on and off in such a manner that the interval of time between the transmission of signals if a function of the magnitude of the meteorological elements being measured.

Nested Grid Model generated every 12 hours by NCEP.

The direction, with respect to magnetic north, from which the wind is blowing. Distinguish from true wind direction.

An instrument for determining the direction from which radio waves approach a receiver. It may consist of a manually operated direction indicator, or it may use a servo system to position the antenna automatically in the direction of the incident waves.

A recording weight barometer.

Wind with a speed between 4 and 6 knots (4 and 7 mph), Beaufort scale number 2.

Precipitation caused by the ascent of moist air over an orographic barrier such as a Mountain range.

Occupational Safety and Health Administration. A regulatory office of the U.S. Department of Labor.

The nautical mile is closely related to the geographical mile which is defined as the length of one minute of arc on the earth's equator. By international agreement, the nautical mile is now defined as 1852 meters.

A cup anemometer with its shaft mechanically coupled to a magneto.

A contact anemometer connected to an electrical circuit which is so arranged that the average wind speed is indicated.

Sir Napier Shaw's name for the approximate absolute temperature scale,

A vector term which includes both wind speed and wind direction.

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

Same as marine rainbow.

Pyrheliometer based on the comparison of the heating of two identical metal strips, one exposed to radiation, the other to a joule effect.

That part of snow melt that reaches stream channels as runoff.