Officials in Hawaii are urging residents to prepare for heavy rains and flooding as Hurricane Lowell, a major Category 3 storm, prompted forecasters to issue a tropical storm warning for two islands. The National Hurricane Center issued the warning Sunday for Kauai and Niihau. Lowell is forecast to skirt Hawaii to the west as it travels north. The Kauai Emergency Management Agency is telling residents to stay home and be prepared to remain there for several days. Tropical storm conditions were expected on Kauai and Niihau by Monday afternoon or evening. The rainfall could produce flash flooding and mudslides.