Its cause: Global Warming.
How do we know?
Global warming blamed for increasing heavy rain in JapanUnless the Japanese "globe" is warming while Bland County, Virginia's isn't, how do "scientists explain the fact that we are suffering through a rather substantial drought here this summer?
The frequency of downpours of over 50 millimeters of rain per hour and heavy rain of more than 200 millimeters per day has surged in recent years, Meteorological Agency data has shown.
Weather officials say the effects of global warming are a likely cause of the heavy rainfalls shown in data held in the agency's Automated Meteorological Data Acquisition System (AMEDAS).
"There is a possibility that cases in which heavy rain falls repeatedly in the same areas like Niigata Prefecture and Fukui Prefecture last year will increase," agency officials said. (link)
Sometimes I wonder about the competency of some of these weather prognosticators.