Weather forecasting social media style

I have an idea about hyper-local, live weather forecasting just based on people stating, in real time, what the weather is now, where they are.  With enough input a very accurate and localised weather forecast could be created.

It would just plot the weather as it is now, onto a map which can be played back up to the current point in time.  Bands of localised 'now-weather' would be animated on the map indicating where the rain has been and the direction it is travelling up to 'now'. Software could then take over and continue the animation into the future based on previous direction of travel and wind speed and direction data.  On the other hand, people may just prefer seeing the weather coming their way and predicting its path towards them (and its E.T.A.) themselves.  Releasing an API for the data would enable others to develop the idea into other areas much the way Twitter allows its API to be used to enrich the Twitterverse.

All the various existing social networks could be used to contribute to this service.  People could use specific tags on Twitter: #rain #rainstop #sun #wind etc. A service could search and plot these tags along with the geocode location data to contribute.  Specific apps could be written just for weather reporting with pics of the weather types to just tap to describe the current weather. I think letting other people know if its just started raining (or just stopped) could become as addictive as telling people what they've just eaten for lunch (Twitter) or where they have just stopped to do the shopping (FourSquare).  At least this will contribute to a very useful service which everyone could use.  Just think how excited people will get when it starts snowing!