The NEXRAD Technical Advisory Committee (TAC) is chartered by the NEXRAD Program Management Committee. The TAC is composed of a Chair; an Executive Secretary; four members each from the Departments of Commerce, Defense, and Transportation; and, two at-large members. The Chair's term is two years (renewable); the Executive Secretary's position is fixed by the charter; agency members serve indefinite terms at the pleasure of their Departments; and, the at-large members are appointed by the Chair. See the charter on the Reference page for more information.