  We have analyzed the variability and spectral evolution of the prototype
dwarf nova system SS Cygni using RXTE data and AAVSO observations. A series of
pointed RXTE/PCA observations allow us to trace the evolution of the X-ray
spectrum of SS Cygni in unprecedented detail, while 6 years of optical AAVSO
and RXTE/ASM light curves show long-term patterns. Employing a technique in
which we stack the X-ray flux over multiple outbursts, phased according to the
optical light curve, we investigate the outburst morphology. We find that the
3-12 keV X-ray flux is suppressed during optical outbursts, a behavior seen
previously, but only in a handful of cycles. The several outbursts of SS Cygni
observed with the more sensitive RXTE/PCA also show a depression of the X-rays
during optical outburst. We quantify the time lags between the optical and
X-ray outbursts, and the timescales of the X-ray recovery from outburst. The
optical light curve of SS Cygni exhibits brief anomalous outbursts. During
these events the hard X-rays and optical flux increase together. The long-term
data suggest that the X-rays decline between outburst. Our results are in
general agreement with modified disk instability models (DIM), which invoke a
two-component accretion flow consisting of a cool optically thick accretion
disk truncated at an inner radius, and a quasi-spherical hot corona-like flow
extending to the surface of the white dwarf. We discuss our results in the
framework of one such model, involving the evaporation of the inner part of the
optically thick accretion disk, proposed by Meyer & Meyer-Hofmeister (1994).
