HONOLULU — Hawaii officials urged people in hard-hit areas to evacuate Saturday due to the state's worst flooding in more than 20 years, after heavy rains fell on soil already saturated by downpours from a winter storm a week ago with still more expected over the weekend. Muddy floodwaters smothered vast stretches of Oahu's North Shore, a community world-renowned for its big-wave surfing. Raging waters lifted homes and cars and prompted evacuation orders for 5,500 people north of Honolulu, though they were later lifted. Authorities cautioned that a 120-year-old dam could fail. On the island of Maui, authorities upgraded an evacuation advisory to a warning for some parts of Lahaina, which is still reeling from a deadly 2023 wildfire, because of retention basins nearing capacity. North Shore Oahu residents who did not evacuate were heartened in the morning by receding waters and moments of blue skies, but more rain was on the way. “Don’t let your guard down just yet,” said Tina Stall, a meteorologist with the National Weather Service in Honolulu, “there’s still potential for mo