Today’s Headlines 1/20/2012 (Updated 3:45 p.m.)(Crain’s) — The Chicago Transit Authority has rerouted all buses from Lake Shore Drive this afternoon as a winter storm bears down on the city.The mass transit agency said that buses that use Lake Shore Drive would be diverted to nearby surface streetsdue to road conditions. The agency said in a news release that 15 routes are affected, and all will make every local stop.Airlines continue to cancel flights — at last count, more than 700 — as the city of Chicago deploys its fleet of plows and salt trucks.More than 600 flights coming to and leaving from O’Hare International Airport were scratched as of 3:30 p.m., according to a Chicago Department of Aviation report. Half of them had been canceled pre-emptively as the city battled the second storm of the month.O’Hare is experiencing delays of 45 minutes or longer.Southwest Airlines canceled more than 100 flights today, including all flights between 2 and 5 p.m., at Midway Airport. The National Weather Service says up to 8 inches of snow could fall today, and it has issued a winter storm warning that is in effect until 9 p.m.(Keep on top of the storm with the National Weather Service’s winter weather briefing page.)Forecasters said snow could fall at a rate of an inch or more per hour during the fast-moving storm.Chicago deployed 278 plows on main streets and Lake Shore Drive, according to a Department of Streets and Sanitation report. Residents can follow the city’s snow-fighting progress in real time through the Plow Tracker map, available on ChicagoShovels.org.(The Associated Press contributed to this report.) Related Content