  We present a search for a Higgs boson decaying to two W bosons in ppbar
collisions at sqrt(s)=1.96 TeV center-of-mass energy. The data sample
corresponds to an integrated luminosity of 3.0 fb-1 collected with the CDF II
detector. We find no evidence for production of a Higgs boson with mass between
110 and 200 GeV/c^2, and determine upper limits on the production cross
section. For the mass of 160 GeV/c^2, where the analysis is most sensitive, the
observed (expected) limit is 0.7 pb (0.9 pb) at 95% Bayesian credibility level
which is 1.7 (2.2) times the standard model cross section.
