12-09-2012, 03:58 AM
To add on to what Carey said, there was data released a few months ago that documented a decline in the frequency of trade winds over the last couple of decades, probably a result of warming. That said, I'm sure this was not unprecedented. In the winter of 1994-95 it did not rain in Volcano (which normally gets more than Hilo) for two or three months, and a lot of people's catchment tanks went dry including mine. I'd be surprised if Rainbow Falls was flowing then. But then, it wasn't a solid drought like now - the kona storms eventually came.