A non-dimensional number relating vertical stability and vertical shear (generally, stability divided by shear). High values indicate unstable and/or weakly-sheared environments; low values indicate weak instability and/or strong vertical shear. Generally, values in the range of around 50 to 100 suggest environmental conditions favorable for supercell development.
BULK RICHARDSON NUMBER (OR BRN)
Meaning of BULK RICHARDSON NUMBER (OR BRN) in English
A comprehensive English glossary of weather. Полный английский глоссарий погоды. 2012