Actually, NOAA is quite impressive, and filled with many scientific minds. One of the best US government agencies there is, and woefully underfunded. Most every meteorologist in the US gets most of it's data from NOAA.
As a comparison, it was NOAA that gave very precise predictions on Hurricane Katrina, it was the rest of the government that failed to properly prepare. FEMA, HSA, the rest of the Feds, plus the state and city governments all were pathetic in preparation and response.
I think the "7-day forecast" however is a gimmick. Even NOAA doesn't like posting more than 3 days out, aside from info on approaching weather patterns. But it's your local weather team, plus places like the Weather Channel, Accuweather, etc. who try to one-up each other by telling you what's going to happen a week in the future...and hope you forget what they said by the time it comes.