Two of Hawaii’s islands are under a hurricane warning as Lowell, a Category 3 storm, approaches. Lowell is expected to pass west of Kauai and Niihau late Monday and early Tuesday morning, according to the National Weather Service. A hurricane warning has been issued for both islands, with a tropical storm warning in effect for Oahu. “Preparations to protect lives and property must be completed quickly,” the NWS said. Kauai County Mayor Derek Kawakami urged residents to get off the roads by noon Monday. He credited Kauai’s emergency management team whose preparations put the county “in a good position to be able to weather this storm as one community.” “Hurricane Lowell is going to get a little closer than expected, and what that really means for everyone is that we ask everyone to start sheltering in place,” Kawakami said. Residents living in flood zones were advised to call friends and family in safer areas to see if they could shelter them. Officials referred people to shelter centers as a last resort. “I have to say that what I have observed over the past few days is nothing short of phenomenal,” Kawakami said. “I’ve seen people going out and getting ready.” Niihau Island, located less than 20 miles southwest of Kauai, has no mayor and is technically part of Kauai County. The worst of the storm is expected to occur overnight, but that could change, according to Elton Ushio, Kauai’s emergency management administrator. It warned of the threat of wind, water, flooding and storm surge. “Conditions are deteriorating rapidly,” Ushio said. “You know we’re having several rivers that are reaching flood stage… We could have an extended closure of the Kuhio Highway, but other areas across the island could be affected.” Hurricane Lowell’s maximum sustained winds were recorded at 115 mph Monday morning local time, according to the NWS. The storm is expected to weaken on Tuesday after passing over Kauai and Niihau. Storm surges of 2 to 4 feet are expected, as well as up to 16 inches of rain. Wet conditions in the island’s hills and mountains increase the risk of flash flooding and landslides. There is also a possibility of tornadoes forming on the islands due to strong winds. Lowell previously achieved Category 5 status, but has since weakened. It is one of three cyclones that have swirled in the Pacific over the past week; the others are Hurricane Karina and Hurricane Marie, which brought rain and strong waves to Southern California. This high level of storm activity in the Pacific is consistent with expectations for El Niño, a natural weather pattern characterized by warmer-than-usual sea surface temperatures in parts of the Pacific Ocean. This year’s El Niño is forecast to be exceptionally strong and possibly record-breaking. Hawaii is still recovering from previous bouts of heavy rain and flooding after Tropical Storm Lala impacted the Big Island last month. At least one person died in a storm-related car accident and more than 100,000 people were left without power. Just a week later, Tropical Storm Moke brought more rain. Now, as Lowell passes, some areas of the Big Island could again see up to 12 inches of rain, which could compound the effects of previous storms. Hawaiian Airlines and Alaska Airlines said they planned to suspend flights at Lihue, Kauai’s only airport, as soon as 11 a.m. local time Monday. “We will reassess the forecast and airport conditions at Lihue this afternoon to determine plans to resume flights tomorrow,” the airlines said. “We are giving guests traveling to and from Lihue through tomorrow the flexibility to change or cancel their flights without fees.” United Airlines also said it would be monitoring the situation and offering waivers to customers who want to change their travel plans. The Kauai Emergency Management Agency urged residents to fill gas tanks, charge devices, refill prescriptions and collect water and food ahead of the storm. Residents should be prepared to stay home for several days, the agency said. The county water department similarly recommended that residents stock up on potable water and fill buckets and bathtubs for non-potable use. Hawaii Gov. Josh Green announced that state and county offices on Kauai, including public schools, would be closed through Tuesday due to concerns about Lowell. He urged residents to follow the instructions of local officials and stay indoors. “Closing offices, schools and courts will help keep people off the roads during dangerous conditions and allow emergency crews to focus on protecting our communities,” Green said. Residents began preparations Wednesday, a manager at Kauai’s only Home Depot told NBC News affiliate KHNL. The station reported that generators, tarps and other emergency equipment were purchased at the store. Resident Nouveau Naumu told KHNL he was 10 years old when Hawaii was hit by Hurricane Iniki. He remembered the devastation left by the 1992 storm and was not taking Lowell lightly, he said. “I just remember the strong winds, we were huddled in the bathroom and things were hitting the house, all the debris, and then waking up the next morning you could see the devastation,” Naumu said.