  We present our current best estimate of the plausible observing scenarios for
the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over
the next several years, with the intention of providing information to
facilitate planning for multi-messenger astronomy with gravitational waves. We
estimate the sensitivity of the network to transient gravitational-wave signals
for the third (O3), fourth (O4) and fifth observing (O5) runs, including the
planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study
the capability of the network to determine the sky location of the source for
gravitational-wave signals from the inspiral of binary systems of compact
objects, that is BNS, NSBH, and BBH systems. The ability to localize the
sources is given as a sky-area probability, luminosity distance, and comoving
volume. The median sky localization area (90\% credible region) is expected to
be a few hundreds of square degrees for all types of binary systems during O3
with the Advanced LIGO and Virgo (HLV) network. The median sky localization
area will improve to a few tens of square degrees during O4 with the Advanced
LIGO, Virgo, and KAGRA (HLVK) network. We evaluate sensitivity and localization
expectations for unmodeled signal searches, including the search for
intermediate mass black hole binary mergers.
