The spatial correlation of fluctuating lift forces plays an important role in the buffeting resonse analysis for horizontally long structures. Some recent researchers have pointed out that the spatial correlation scale of the fluctuating lift force acting on bluff bodies is much larger than that of the fluctuating velocity of the approaching flow. To investigate the forming process of the spatial correlation of fluctuating lift forces, the transmission of the weak periodic disturbance generated artifically near the stagnation point of thin plates was examined through the measurements of the surface pressure. As a result of this study, it was clarified that the strength and the frequency of the disturbance did not affect the size of the area including the pressure fluctuation caused by the disturbance, and the width of the area propagated the disturbance changes in proportion to the length of the separation bubble.
