The RMS-amplitude of high-frequency fluctuations during the young turbulent spot formation from a single streamwise elongated streaky structure in a flat plate laminar boundary layer. The vertical axis is a wall-normal coordinate and the horizontal axis is a transversal one. The experimental data were obtained in the MT-324 wind tunnel (ITAM SB RAS) by D.S. Lokhov and D.S. Sboev.