Lifting condensation level was estimated from surface parameters and compared against ceilometer derived cloud base measurements in order to identify periods of drying within the mixed layer that may be associated with entrainment of free air into the CBL. CBL depths and growth were inferred from wind profiler signal to noise ratio data and measured parameters such as wind shear. These data were available from the integrated COS dataset. Profiler derived quantities were compared against rawinsonde data available nearby to ensure consistency.
COS measurements suggest that mixed layer growth was greatest during precipitating convection, typically about 4 cm s-1. Estimated CBL heating rates and CBL growth rates were highly correlated, and correspond closely to periods when the observed cloud base deviated from surface based LCL estimates, suggesting entrainment and drying of the mixed layer was enhanced during the convection. In this case, the cloud base "decouples" from the surface, which may sometimes be noted in sounding data as a small discontinuity in CBL profiles. Typical CBL heating rates were between 0.3 and 0.6 0C hr-1, and increasing to 0.6 and 1.20C hr-1 during the more intense convection. Mixed layer growth rates of 4 cm s-1 were typical during convection. Additionally, the cloud environment was warmed and dried by the convection through subsidence and warming as seen in the time series of observed cloud base that exhibit large excursions on short time scales. Entrainment estimates suggest that these mixed layers were controlled primarily by large scale forcing, but entrainment was important in modifying the convective environment as well. Integration of measurements available from COS were useful in identifying thermodynamic and convective characteristics of the convective boundary layer in these lake-effect snow situations.