Judicial astrology is the art of forecasting events by calculation of the planetary and stellar bodies and their relationship to the Earth.
[1][2] In the Middle Ages, natural astrology was mainly focused on the diagnosis and the treatment of medical patients.
An additional use would have been the application of astrology to determine future weather patterns based on the Aristotelian/Ptolemaic rationale that the planets cause change in the sublunary world by producing an efflux of elements and qualities.
Every other branch was lumped together into the heading of 'judicial astrology'.
Judicial astrology is an obsolete category, because since the Middle Ages other sciences have arisen, astrology has ceased to be a tool in medicine and meteorology, and scientifically demonstrable parts of natural astrology such as the moon's effect on tides are considered to be physics not astrology.