  We generate probabilistic predictions of the low-redshift ($z < 0.2$)
synchrotron Cosmic Web for half of the Northern Sky. In particular, we predict
the contribution to the specific intensity function at $\nu_\mathrm{obs} = 150\
\mathrm{MHz}$ from merger shocks in clusters and accretion shocks in filaments,
both of which arise during large-scale structure formation. We assume a
primordial magnetogenesis scenario, but our method is general enough to allow
for an exploration of alternative magnetogenesis scenarios - and even
alternative radiation mechanisms and spectral windows. In the future, by
comparing different predictions, one could infer the most plausible physical
model from a synchrotron Cosmic Web detection. Our method combines Bayesian
large-scale structure reconstructions, snapshots of an MHD cosmological
simulation, a Gaussian random field, and a ray tracing approach. The results
help to select targets for deep observations and can be used in actual
detection experiments. We highlight predictions for the Hercules Cluster, the
Coma Cluster, Abell 2199, Abell 2255, the Lockman Hole and the Ursa Major
Supercluster. At degree-scale resolution, the median specific intensity reaches
$m_{I_\nu} \sim 10^{-1}\ \xi_e\ \mathrm{Jy\ deg^{-2}}$, where $\xi_e$ is the
electron acceleration efficiency.

Cosmology and Nongalactic Astrophysics