Flights were briefly halted at several Washington-area airports Friday after a strong chemical smell was reported at a nearby air traffic control facility, the Federal Aviation Administration said."The FAA has temporarily stoppe d traffic at Ronald Reagan Washington National Airport (DCA), Washington Dulles International Airport (IAD) and Baltimore-Washington International Airport (BWI) because of a strong chemical smell at the Potomac TRACON that is impacting some air traffic controllers," the FAA told Scripps News in a statement.Ground stops at the airports began shortly after 5:30 p.m. Eastern Time and were lifted about two hours later.Affected airports were still experiencing flight delays on Friday evening that could extend for hours, according to the FAA.RELATED NEWS | Spring travel savings hacks, as gas prices and airfares riseA separate ground stop was in effect for Austin-Bergstrom International Airport due to staffing issues.Arriving flights at Seattle-Tacoma International Airport were also briefly stopped earlier on Friday due to snowy and icy conditions.As of Friday afternoon, there had been close to 7,000 delays affecting U.S. flights and 647 cancellations, according to FlightAware.This is a developing story and will be updated. ...read more read less