The theory of the parity-nonconserving alpha decays from the ${2}^{\ensuremath{-}}$ (8.88 MeV), ${0}^{\ensuremath{-}}$ (10.937 MeV), and ${3}^{+}$ (11.05 MeV) ${\mathrm{O}}^{16}$ levels is developed. Using the weak nucleon-nucleon interaction of Blin-Stoyle and Herczeg and known ${\mathrm{O}}^{16}$ wave functions modified by short-range correlations via the Bethe-Goldstone equation, the irregular alpha widths have been related to known regular widths. The influence by the hard core of the strong interaction has been studied.