  Many high-state cataclysmic variables (CVs) exhibit blue-shifted absorption
features in their ultraviolet (UV) spectra -- a smoking-gun signature of
outflows. However, the impact of these outflows on {\em optical} spectra
remains much more uncertain. During its recent outburst, the eclipsing dwarf
nova V455 And displayed strong optical emission lines whose cores were narrower
than expected from a Keplerian disc. Here, we explore whether disc + wind
models developed for matching UV observations of CVs can also account for these
optical spectra. Importantly, V455~And was extremely bright at outburst
maximum: the accretion rate implied by fitting the optical continuum with a
standard disc model is $\dot{M}_{\rm acc} \simeq 10^{-7}~{\rm M}_\odot~{\rm
yr^{-1}}$. Allowing for continuum reprocessing in the outflow helps to relax
this constraint. A disk wind can also broadly reproduce the optical emission
lines, but only if the wind is (i) highly mass-loaded, with a mass-loss rate
reaching $\dot{M}_{\rm wind} \simeq 0.4 \dot{M}_{\rm acc}$, and/or (ii) clumpy,
with a volume filling factor $f_V \simeq 0.1$. The same models can describe the
spectral evolution across the outburst, simply by lowering $\dot{M}_{\rm acc}$
and $\dot{M}_{\rm wind}$. Extending these models to lower inclinations and into
the UV produces spectra consistent with those observed in face-on high-state
CVs. We also find, for the first time in simulations of this type, P-Cygni-like
absorption features in the Balmer series, as have been observed in both CVs and
X-ray binaries. Overall, dense disc winds provide a promising framework for
explaining multiple observational signatures seen in high-state CVs, but
theoretical challenges persist.
