  We study how supersonic streaming velocities of baryons relative to dark
matter -- a large-scale effect imprinted at recombination and coherent over
$\sim 3$ Mpc scales -- affects the formation of dwarf galaxies at $z \gtrsim
5$. We perform cosmological hydrodynamic simulations, including and excluding
streaming velocities, in regions centered on halos with $M_{\rm vir}(z=0)
\approx 10^{10}$ M$_{\odot}$; the simulations are part of the Feedback In
Realistic Environments (FIRE) project and run with FIRE-3 physics. Our
simulations comprise many thousands of systems with halo masses between $M_{\rm
vir} = 2\times10^{5}$ M$_{\odot}$ and $2\times10^9$ M$_{\odot}$ in the redshift
range $z=20-5$. A few hundred of these galaxies form stars and have stellar
masses ranging from 100 to $10^7$ M$_{\odot}$. While star formation is globally
delayed by approximately 50 Myr in the streaming relative to non-streaming
simulations and the number of luminous galaxies is correspondingly suppressed
at high redshift in the streaming runs, these effects decay with time. By
$z=5$, the properties of the simulated galaxies are nearly identical in the
streaming versus non-streaming runs, indicating that any effects of streaming
velocities on the properties of galaxies at the mass scale of classical dwarfs
and larger do not persist to $z=0$.
