Relating WSR-88D spectrum width data to various weather conditions

This presentation will discuss measurements of Doppler spectrum width, the least used of the three Doppler moments, made with the WSR-88D radars in the USA . We will present reasons why there is interest in the spectrum width measurements, and why relatively little use is made of these data. Examples illustrate some of the problems with spectrum width measurements; but when these problems are solved, there is a wealth of information in the spectrum width data fields. Statistical analysis of the spectrum width field is made in volumes of space occupied by various weather types We classify spectrum width statistics, in particular its median value in a volume of weather, by weather type. We will show that, surprisingly, spectrum width data in a severe tornadic storm, one that destroyed thousands of homes and killed over 40 people in Moore Oklahoma, had values expected from fair weather. The data suggests that this storm has quasi-laminar, but strong flow.