  We consider the semiclassical Schr\"odinger-Poisson system with a special
initial data of WKB type such that the solution of the limiting hydrodynamical
equation becomes time-global in dimensions at least three. We give an example
of such initial data in the focusing case via the analysis of the compressible
Euler-Poisson equations. This example is a large data with radial symmetry, and
is beyond the reach of the previous results because the phase part decays too
slowly. Extending previous results in this direction, we justify the WKB
approximation of the solution with this data for an arbitrarily large interval
of $\R_+$.
