The National Weather Service placed central Clark County, including the Las Vegas metropolitan area, under a severe-thunderstorm warning until 4 p.m. PDT Thursday. Forecasters said a storm moving east at about 15 mph could unleash wind gusts up to 60 mph and quarter-size hail, threatening vehicles, roofs and trees across Henderson, Boulder City, the Las Vegas Strip and surrounding communities. The advisory also covers Harry Reid International Airport and a stretch of Interstate 15, prompting officials to urge motorists and airline passengers to monitor conditions and move to sturdy shelter when thunder roars. Farther north, the Weather Service’s Reno office issued successive severe-thunderstorm warnings and special weather statements for Lassen and Modoc counties in northern California and for Washoe and Mineral counties in western Nevada. Those alerts extend into the early evening, with storms capable of producing damaging winds, brief downpours and frequent lightning as they sweep across the high desert and the eastern Sierra foothills. Residents across the warned areas are advised to secure outdoor items, avoid windows and remain indoors on the lowest floor of a building until the storms pass. Additional updates will be issued as the fast-moving cells evolve.