Airfoil analysis is essential to wind turbine aerodynamics. In typical operating conditions, airfoils undergo transition from laminar to turbulent flow in the boundary layer in a manner that must be modeled accurately to predict airfoil lift and drag. There are different modes of transition (e.g. natural, by-pass, wake induced, reversed, separated flow) and modeling them is not straight-forward. Over the years, diversified predictions have been developed for the various modes. One of the popular transition models is the local correlation-based ƴ - Re₀ model of Menter et al. (Menter et al., 2004). The model requires data correlations for the transition length and the critical Reynolds numbers.