The length of air flow past a wind vane required for the vane to respond to 50 percent of a step change in wind direction. Expressed in feet or meters and calculated from delay time times wind tunnel speed.

Having a specific relationship to a time base or clock. In synchronous communications, data characters are sent according to a timing signal which synchronizes the two communicating devices.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

Any device or instrument for measuring salinity, especially one based on electrical conductivity methods.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

A recording siphon barometer.

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

The time required for an instrument to register a designated percentage (frequently 90%) of a step change in the variable being measured.

A graphical representation of stage or discharge at a point on a stream as a function of time.

The center of an area of high pressure, usually accompanied by anticyclonic and outward wind flow. Also known as an anticyclone.

Winds from the four cardinal points of the compass; that is, north, east, south, and west winds.

In general. the severe wind of an intense tropical cyclone (hurricane or typhoon). The term has no further technical connotation, but, unfortunately, is easily conftlsed with the strictly defined hurricane-force wind,

Pertaining to rain, or more broadly, to precipitation.

The state of the weather with respect to its effect upon the kindling and spreading of forest fires.

A faintly-colored circular arc similar to a rainbow but formed on fog layers containing drops whose diameters are 100 microns or less. Also called mistbow, white rainbow.

Abbreviation for precipitation effectiveness index.

The change in a performance characteristic caused by a change in a specified operating condition from reference operating condition, all other conditions being held within the limits of reference operating conditions.

A set of rules or conventions used to standardize data transfer between devices.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the mass of dry air. For many purposes, the mixing ratio may be approximated by the specific humidity.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.