Relentless rain in Hawaii has left parts of the state under the threat of “significant and life-threatening flooding,” the National Weather Service in Honolulu said Monday night, with some areas already tallying more than a foot of rain over a 48-hour span.Relentless rain in Hawaii has left parts of the state under the threat of “significant and life-threatening flooding,” the National Weather Service in Honolulu said Monday night, with some areas already tallying more than a foot of rain over a 48-hour span.