A fast-moving storm spread snow across the U.S. Northeast on Tuesday, tying up air traffic and boosting spot energy prices as electricity demand surged.

New York may receive 2 to 4 inches before the storm ends late today, the National Weather Service said. Boston may get 8 inches, said Alan Dunham, a weather service meteorologist in Taunton, Massachusetts.

As of early afternoon in New York (about 10 a.m. Pacific time), 184 flights at Newark Liberty International Airport in New Jersey and 84 at New York’s LaGuardia had been canceled, according to FlightAware, a Houston-based airline tracking service. Newark in particular was being affected by ice and snow.