It has been hypothesized that biogenic aerosol formation in the southern Finland troposphere can be predicted using micrometeorological parameters and knowing pre-existing aerosol surface area in the previous publication. There the concurrence of nucleation beginning with the rapid growth of convective boundary layer was demonstrated. In this work a nucleation probability term is introduced using statistical correlation between the particle formation and micrometeorological parameters. More refined analysis presented here demonstrates the increasing probability of nucleation mode aerosol presence with the increasing heat flux, temperature standard deviation, and vertical wind speed variance. Diurnal maximal values of the parameters mentioned are larger on days with nucleation event than on days without although these values are not significantly different during the convective layer growth. What distinguishes days with nucleation events is the size of condensation sink, which is significantly smaller on days with events than on days without.