Abstract <p>The phenomenon of weak but finite quantum entanglement at the macrolevel leads to nonlocal correlations of almost isolated random dissipative processes. Long-term experiments studying macroscopic nonlocal correlations between random dissipative heliogeophysical processes and random processes in detectors have revealed the important properties of macroscopic entanglement predicted by quantum absorber electrodynamics. These correlations have retarded and advanced components, whereby, due to the asymmetry of the absorption efficiency of the corresponding components of the Wheeler–Feynman electromagnetic field by the medium, the advanced correlation exceeds the retarded one. Although advanced correlation corresponds to reverse-time causality, for random processes this does not lead to paradoxes. This kind of advanced correlation allows forecasting the random components of solar and geomagnetic activity by observing a probe process in a detector isolated from classical local influences. Long-term series of observations under laboratory–observatory conditions and during the deep-water experiment in Lake Baikal have proven the possibility of such forecasts with a lead time of several months and with an accuracy sufficient for all practical purposes.</p>