Alert sent from the US FAA a few minutes ago regarding air traffic control outage:

NATIONWIDE GROUND STOP INITIATED DUE TO U.S. NOTAM SYSTEM OUTAGE.

https://www.fly.faa.gov/adv/adv_otherdis.jsp?advn=13&adv_date=01112023&facId=DCC&title=NOTAM+SYSTEM+EQUIPMENT+OUTAGE_FYI&titleDate=01/11/23