The BRN is used frequently in meteorology due to widely available radiosonde data and numerical weather forecasts that supply wind and temperature measurements at discrete points in space.
[2] Below is the formula for the BRN, where g is gravitational acceleration, Tv is absolute virtual temperature, Δθv is the virtual potential temperature difference across a layer of thickness, Δz is vertical depth, and ΔU and ΔV are the changes in horizontal wind components across that same layer.
Generally, values in the range of around 10 to 50 suggest environmental conditions favorable for supercell development.
Numbers less than this critical value are dynamically unstable and likely to become or remain turbulent.
[1] The critical value of 0.25 applies only for local gradients, not for finite differences across thick layers.