FAA issues nationwide ground stop due to "extraordinary circumstances"

What they're saying: "The FAA issued a nationwide ground stop for all U.S. airports following communication issues impacting multiple Air Route Traffic Control Centers," the agency said in a statement.

• "FAA technicians are investigating the issue. We will provide updates."

How it works: Air Route Traffic Control Centers, often simply called "centers," mostly handle high-altitude en route airspace between airports.

Between the lines: The FAA has been rolling out a new AI tool designed to help manage airspace congestion, but it's unclear if that system has any connection to Friday's communication issues.

Our thought bubble, from Axios aviation expert and pilot Alex Fitzpatrick: With no planes departing anywhere, airports nationwide may quickly run out of gates and room for the thousands of flights navigating the crisis while already airborne.

The bottom line: It's likely going to be a messy night — and the effects could easily spill over into the weekend.

This is a breaking news story and will be updated.