Reuters: Tropical downpours are becoming more frequent and the trend seems worse than expected, bringing greater risks of flash floods, scientists said on Thursday. “As the tropics warm are are seeing an increased frequency in the heaviest rainfall,” said Richard Allan of the University of Reading in England, who co-authored a study of tropical rains with Brian Soden of the University of Miami. The satellite review of tropical rainstorms since the 1980s gave the first observational …