There are different factors that make some things predictable and some not. Many models use the solar rotation as a baseline, so some structure that was there i

There are different factors that make some things predictable and some not. Many models use the solar rotation as a baseline, so some structure that was there in one rotation will likely be there in the next one (this is similar to persistence modeling in climate). Sudden, large CMEs are not necessarily predictable, but they may be to some degree, most of the solar wind modeling efforts are aimed at determining the time of arrival of a structure on the Sun at Earth (or whether it will arrive) rather than determining if such a structure will happen or not, though as I said, there are some ways to make educated guesses. Once you think a CME will be Earth directed, the important factors are how strong it is (magnetic field and proton density) and how soon it will arrive. Steady solar wind takes about four days to make the journey but huge solar flares may take less than 24 hours, all told, this is still plenty of time for most satellite operators to prepare their satellites by baffling them or taking other precautionary measures.