  We present the results of a large grid of synthetic spectra and compare them
to early spectroscopic observations of SN 1993W. This supernova was discovered
close to its explosion date and at a recession velocity of 5400 km/s is located
in the Hubble flow. We focus here on two early spectra that were obtained
approximately 5 and 9 days after explosion. We parameterize the outer supernova
envelope as a power-law density profile in homologous expansion. In order to
extract information on the value of the parameters a large number of models was
required. We show that very early spectra combined with detailed models can
provide constraints on the value of the power law index, the ratio of hydrogen
to helium in the surface of the progenitor, the progenitor metallicity and the
amount of radioactive nickel mixed into the outer envelope of the supernova.
The spectral fits reproduce the observed spectra exceedingly well. The spectral
results combined with the early photometry predict that the explosion date was
4.7 \pm 0.7 days before the first spectrum was obtained. The ability to obtain
the metallicity from early spectra make SN IIP attractive probes of chemical
evolution in the universe and by showing that we have the ability to pin down
the parameters of the progenitor and mixing during the supernova explosion, it
is likely to make SN IIP useful cosmological distance indicators which are at
the same time complementary to SNe Ia.
