  A suite of numerical model-derived turbulence assessment products has
recently been developed by NESDIS/STAR and implemented on the World Wide Web.
The existing product suite is intended to provide turbulence information to
aircraft flying in the vicinity of the jet stream. Turbulence is also a
frequently occurring phenomenon in the boundary layer and may pose a threat to
low-flying aircraft and aircraft during the take-off and landing phases of
flight. Therefore, a numerical model-derived boundary layer turbulence product
is under development. The boundary layer turbulence index (TIBL) product is
designed to assess the potential for turbulence in the lower troposphere,
generated using National Center for Environmental Prediction (NCEP) Rapid
Update Cycle (RUC)-2 model data. The index algorithm approximates boundary
layer turbulent kinetic energy (TKE) by parameterizing vertical wind shear,
responsible for mechanical production, and kinematic heat flux, responsible for
buoyant production. The TIBL product is expected to be most effective during
the afternoon hours in a regime characterized by a quasi-steady state
convective mixed layer. Preliminary case studies and validation have revealed a
strong correlation between the presence of TKE maxima and peak wind gust
magnitude observed at the surface in evolving morning or mature afternoon mixed
layers.
