Discretizing your domain into a grid doesn't necessarily imply you're solving the problem in question using cellular automata. I'm not familiar with the specif

Discretizing your domain into a grid doesn't necessarily imply you're solving the problem in question using cellular automata. I'm not familiar with the specifics of GFS, but it's common to model physical phenomena using the finite difference method. It's newsworthy and interesting because they're running the same exact model on two different computers and it's yielding wildly divergent results. It'd be as if you took the same CA rules with the same initial state and it ran differently on two different computers. It's tricky because these discrepancies are probably due to subtle differences like the way the new CPUs are handling the floating point calculations.