Predicting radio activity in X-ray binaries with optical/infrared monitoring

X-ray binaries undergo outbursts due to increased mass accretion rate in the disc towards the compact object, a black hole or neutron star. Recently, a picture has developed where the behaviour between the radio, optical/infrared and X-ray luminosities during these outbursts are correlated. Here, I review this picture and show how simple optical/infrared monitoring can predict radio flux densities. Using these predictions it will be possible to prepare radio telescopes accordingly, eventually improving radio sampling of X-ray transients. In particular, it is possible to infer when the bright, optically thin jet flares are likely to occur in black hole transients. We find that the hard-to-soft X-ray state changes, which also can be identified by optical/infrared colour changes, lead the bright optically thin radio outbursts by ∼ 10 days.