A model is developed that relates the poleward leaps of the westward traveling surge (WTS) and the generation of Pi 2 pulsations. The feedback instability developed by Sato and coworkers is combined with the dynamic surge model of Rothwell et al. (1984). We find that our previous results on the motion of the WTS are related to the zero-order terms in the Sato formulation. The linearized first-order terms give rise to a dispersion relation with solutions in the Pi 2 frequency range. The Ith frequency, fI, is found to be turned on in integer multiples of one-half the Alfv¿n bounce frequency between the ionosphere and the plasma sheet. Most important, however, is that the Ith frequency is turned on only when the precipitating electron energy exceeds a certain value. As previously shown, the velocity of the poleward surge boundary also increases when the energy of the precipitating electrons is enhanced. Therefore the poleward leap of the surge during substorm onsets is accompanied by the generation of higher Pi 2 frequency components. The time evolution of the composite Pi 2 pulse is obtained using the calculated decay rates, and agreement with data is shown.