  We present a realistic modeling of the dipole component of the projected sky
distribution of NVSS radio galaxies. The modeling relies on mock catalogs
generated within the context of $\Lambda$CDM cosmology, in the linear regime of
structure formation. After removing the contribution from the solar motion, the
mocks show that the remaining observed signal is mostly (70\%) due to
structures within $z\lesssim0.1$. The amplitude of the model signal depends on
the bias factor $b$ of the NVSS mock galaxies. For sources with flux density, $
S> 15 \; \rm mJy$, the bias recipe inferred from higher order moments is
consistent with the observed dipole signal at $2.12\sigma$. Flux thresholds
above $20 \; \rm mJy$ yield a disagreement close to the $3\sigma $ level. A
constant high bias, $b=3$ is needed to mitigate the tension to the $\sim
2.3\sigma$ level.
