Originally posted by gaweidert I actually live across the street from one of our local TV meteorologists. He admits that once they get past a 4 hour window the reliability of the forecast starts declining rapidly. They still rely on experience with local weather weather patterns to develop their forecast. Interesting enough back in the mid 1970's I read the handbook that went along with private pilot's ground school. Back then they said the same thing.
My sister-in-law has a doctorate in meteorology and works for NASA. She confirms what's kind of common sense, that the farther out in time you go the less the prediction is model-based and the more it's just historical averages. A week out is decently reliable, more than that is mostly what it's supposed to do that time of the year.
She also says that
The Capital Weather Gang is quite good, at least for those around DC.