occurrence of rain or lack thereof is not like flipping a coin Yes, absolutely. El Nino is a fine reason to believe that the pattern will change. At a decada

occurrence of rain or lack thereof is not like flipping a coin Yes, absolutely. El Nino is a fine reason to believe that the pattern will change. At a decadal scale, there is reason to believe that recent drought is a predictor of future rain. My point though was that there was not (a priori) a reason to believe that "It's been 500 years since California has been this dry" would imply "we are due" for a 1000 year storm.