American Airlines briefly grounded its flights across the United States on Tuesday evening after an IT outage disrupted connectivity across the carrier's systems, with Colorado among the states affected by broader aviation disruptions that night.

A nationwide ground stop was issued for less than an hour Tuesday evening due to the IT outage, the airline said. The ground stop went into effect around 6:30 p.m. Eastern Time and began to resolve shortly afterward.

"A technology issue briefly impacted connectivity for some of our systems on Tuesday evening. Systems are coming back online now and flights are departing again," American Airlines said in a statement on X. While it was not immediately clear what caused the outage, the airline said a temporary ground stop was put in place while teams worked to resolve the issue. "We apologize to our customers for the inconvenience," the airline said.

Elsewhere in the U.S. on Tuesday, heavy thunderstorm activity was causing unrelated ground delays and ground stops at airports, including in Colorado, Massachusetts, Maryland, Virginia and New York. The ground stop came during an unusually strong storm moving through the Northeast through Tuesday night that could drop more than a month's worth of rain in parts of the region.

More than 2,500 flights were canceled at airports across the U.S., according to FlightAware. New York City's airports were the most impacted, along with Newark Liberty International Airport in New Jersey, as thunderstorms forced ground stops at airports across major cities including New York, Newark, Washington, D.C., and Baltimore.

The extent of specific delays at Colorado Springs Airport tied to the American Airlines IT outage had not been separately reported as of Tuesday night, and the cause of the technical outage remains outstanding.