Cycle

The Cycle or the 'Storm' is an anomaly storm that makes enemies stronger and releases powerful radiation.

Summary
Fortuna III was terraformed by aliens a long time ago. The Federation tried colonizing it, but the Cycle put an end to that. The world-spanning storms kill anything dumb enough to set foot planetside, and these storms are happening more often than not. The planet dangerous inhabitants have learned to survive on the surface and even draw power from the storms that pass over the surface of the planet. The closer you are to the next Cycle, the stronger the enemies on the planet. The storm itself releases powerful radiation will tear your insides apart if you don't make it to the evac ship.