The Hawaii Tourism Authority says it's "business as usual" for the islands as Tropical Depression Darby leaves the state. Darby was downgraded Monday from a tropical storm, but it is still expected to bring 1 to 3 inches of additional rainfall over parts of the islands. Darby was downgraded Monday from a tropical storm but is still expected to bring 1 to 3 inches of additional rainfall over parts of the islands. Tropical storm warnings for Oahu and Kauai have been called off as the system moves away from Hawaii, but flash flood watches are still in effect. Heavy rains from a tropical storm passing near Hawaii caused driving woes on Oahu. According to KHON-TV, the Honolulu Fire Department said that as of 10 p.m.