"The National Weather Service is currently in the process of transitioning its primary computer model, the Global Forecast System (GFS), from an old supercomputer to a brand new one.  However, before the switch can be approved, the GFS model on the new computer must generate forecasts indistinguishable from the forecasts on the old one." - Amit Patel

They can't be better? - Todd Hoff

Amit, I have a sort of game programming question. I'd like to simulate waves rolling up on a beach. There's a periodicity to it, the lines are irregular, and they have surprising jumps. Any thoughts on how to do that sort of thing? - Todd Hoff

Holy crap, it produces different results because of the way the computer compiles? So they don't really want to run the GFS, they want to emulate it? This is blowing my mind. - Meg VMeg

Todd: I'd probably add up a bunch of sine waves and see if that's good enough. If you add together lots of sines you can get unprectable-ish patterns (surprising jumps) http://www.wolframalpha.com/input... - Amit Patel