It's not all that hard to predict short-term weather. Just look at satellite and radar, and see what's coming in from whatever direction, and find out what the weather is like upstream. Factor in usual seasonal history, and you're 90% there. That's good for a few days, maybe, cartainly not two weeks. Here in SF, the 2-week and longer forcasts are essentially worthless. Pretty much 1 week, too.
It's fun to check the temperatures reported by unofficial, and official, weather stations in a small region. Temps can have a 10 degree F spread. One explanation for AGW is instrumentation error; air temperature is really hard to measure to 1 deg C accuracy.