I think this stuff relates to weather models, though the moderators might disagree.
Some peeps blame 'faulty software', others cite all sorts of problems arising from a human perspective; but, ultimately, it's mostly down to good old Chaos; simple equations (be they weather-related or not) involving feedback can create an almost unimaginable degree of complexity.
I wonder whether the next generation of AI-/Machine Intelligence-based models will ever 'cut the mustard'.