SW velocity and density are very difficult parameters for a reliable forecast. Even in the clearest and most evident cases of the so-called post-flare coronal mass ejections, the amplitude and duration of the increase after a flare will depend on many parameters,such as a magnitude of the flare, its position on the solar disk,magnetic field structure in the active region and
interplanetary space,direction of the outburst,and its solid angle.Therefore, establishment of an additional parameter affecting SW velocity may open new opportunities for the improved forecast and analysis of its variations.