  We study three quasar radio sources (B1257-326, B1519-273, and J1819+385)
that show large amplitude intraday and annual scintillation variability
produced by the Earth's motion relative to turbulent-scattering screens located
within a few parsecs of the Sun. We find that the lines of sight to these
sources pass through the edges of partially ionized warm interstellar clouds
where two or more clouds may interact. From the gas flow vectors of these
clouds, we find that the relative radial and transverse velocities of these
clouds are large and could generate the turbulence that is responsible for the
observed scintillation. For all three sight lines the flow velocities of nearby
warm local interstellar clouds are consistent with the fits to the transverse
flows of the radio scintillation signals.
