NOAA and get educated in weather forecasting and how it actually works. Then you can read the forecast discussion and make sense of things.
The 15-day on accuweather is ok for general temperature trends, but past 7 days, the predictibility of rain/snow/sun drops off considerably and it can be strongly argued that those are better used for entertainment.
I'm not a fan the The Weather Channel as I find they focus primarily on highly populated areas, and neglect the mountainous areas greatly.