The detailed structure and evolution of current and hydrography after a wind storm, typhoon T9313, is described from an intensive field study. The study was done using current meters deployed at 8 stations, as well as 15 thermistor chains, in the southern part of the North Basin of Lake Biwa in summer of 1993. In the morning of 4 September, strong southerly winds with the maximum speed of more than 20 m ⋅see^-1 blew over the lake. After the wind speed peaked, the cold water in the thermocline of the North Basin intruded into the South Basin. This intrusion of cold water was induced by the surface seiche which was generated by the winds of the typhoon. Then a large amplitude internal surge (a steepfronted depression wave on the thermocline) traveled from north to south along the west coast of the North Basin as an internal Kelvin wave. The internal surge shoaled over the southern slope of the North Basin and finally collided against the slope. When the surge shoaled over the slope, a strong jet of over 60 cm⋅s^-1 was generated in the lower benthic layer (benthic jet). Assuming the internal surge as a moving internal jump, we explain the mechanism which induced the benthic jet. When the surge collided against the slope, a homogeneous mixed water mass was generated in the thermocline. After the collision, the internal surge was reflected to travel north along the east coast of the North Basin.