Follow live updates as flight reductions begin today at 40 high-traffic airports in what officials have described as a "proactive" effort to alleviate pressure points.

As many as 1,800 flights could be affected on Friday alone, according to Cirium, an aviation-data provider. The final figure will depend on which airports are targeted. The FAA estimates that it handles an average of more than 44,000 flights a day.

FLETCHER – The Asheville Regional Airport was relatively quiet and uncrowded Nov. 7, the first day after a Federal Aviation Administration mandate to reduce flights out of certain airports.

American Airlines said that the 4% reduction will mean 220 canceled flights per day. The vast majority of impacted American Airlines flights are regional, and there’ll be no impact to international flights including Mexico, Canada and the Caribbean, CEO David Seymour said in a letter to employees. Further hub-to-hub routes impact will be minimized.

The Federal Aviation Administration has issued a ground stop at Nashville International Airport due to weather.

Only two flights have been canceled so far at McGhee Tyson on Nov. 7. Knoxville, so far, has avoided the brunt of the government shutdown impacts on airports. Unlike other Tennessee airports, like Nashville International Airport, long security lines and delays have been minimal.

Sara Nelson, president of the Association of Flight Attendants, joins Morning Joe as hundreds of flights are canceled amid the ongoing government shutdown, warning the system is “unsustainable” and that people “will break” if air traffic workers remain unpaid.

TSA wait times at George Bush Intercontinental Airport were expected to exceed 45 minutes to an hour, according to airport officials.