The Brief Thunderstorms prompted a ground stop at O'Hare Airport Sunday afternoon, halting landings and departures around 3:30 p.m., according to the FAA. A ground stop was issued at O'Hare Airport Sunday afternoon due to thunderstorms. What we know:Thunderstorms prompted the Federal Aviation Administration to halt landings and departures at O'Hare Airport around 3:30 p.m. The ground stop is in effect for O'Hare until 4:45 p.m. So far, two have been canceled at O'Hare Airport.