  We present a general procedure for deriving a line profile model for massive
star X-ray spectra that captures the dynamics of the wind more directly. The
basis of the model is the analytic solution to the problem of variable jets in
Herbig-Haro objects given by \citet{Canto2000}. In deriving our model, we
generalize this jet solution to include flows with a prescribed nonzero
acceleration for the context of radiatively driven winds. We provide example
line profiles generated from our model for the case of sinusoidal velocity and
mass ejection variations. The example profiles show the expected shape of
massive star X-ray emission lines, as well as interesting but complicated
trends with the model parameters. This establishes the possibility that
observed X-rays could be a result of temporal variations seeded at the wind
base, rather than purely generated intrinsically within the wind volume, and
can be described via a quantitative language that connects with the physical
attributes of those variations, consistently with the downstream
momentum-conserving nature of radiatively cooled shocked radial flows.
