La Niña arrived March 3. The rain started weeks before that, but it's as close an explanation for this 'event' as we're likely to get. A lot of the state has already passed their rainfall average for the year.
So on Day 41, we have more landslides mauka, more flooding windward, and the end of a 47 million gallon sewage spill that closed Waikiki beaches. This morning the news reported that the beaches might be closed for weeks, even months, until the bacteria levels fall.