Spectrum width is a measure of the variance in velocity within each bin. It is actually generated from a pulse pair algorithm, rather than being computed directly from velocity data. The product is generated using 7 levels, with a maximum possible width of 20 kt. Anything beyond 20 kt is truncated by the radar unit.
The spectrum width product it is the basis for the WSR-88D turbulence products. The application of the product to severe thunderstorm forecasting is not known, but it may be a secondary indicator of small tornadoes, landspouts, and gustnadoes.
32 nm. Uses the close-range radius of 32 nm at 0.13 nm resolution.
124 nm. Uses the standard radius of 124 nm at 0.54 nm resolution.