Would be good wouldn't it.
People sometimes email asking for this because their wedding is 2 months away, and they want to know if it will rain.
Getting 7 days out accurate is currently a challenge as weather systems are so complex.
Plus, to make an accurate forecast, you need to kick off with an accurate 'current state' of the weather. Otherwise .. garbage in .. garbage out.
There are a heap of weather balloons, land and sea based measuring stations, but given the scale of weather (horizontally & vertically), these stations are still a pretty course measurement of things...
