"We are aware of system issues and are working quickly to resolve," the company tweeted just after 2 p.m. ET. "We will share more info soon."

In a new statement, a company spokesperson said Southwest "proactively canceled" about 500 flights on Tuesday due to the issues and was working with impacted customers on how to get them to their destinations.

The airline blamed Tuesday's issues on "intermittent performance issues with our network connectivity."

The hiccups began Monday night when a misfire of the company’s third-party weather data provider prompted the airline to ground its jets for several hours before some flights resumed.

"We are beginning to resume flight operations after our third-party weather data provider experienced intermittent performance issues earlier this evening preventing transmission of weather information that is required to safely operate our aircraft," the company said in a statement. "While Southwest Teams and the vendor worked to restore connectivity, we implemented a ground stop to protect the Safety of our Crews and Customers."

The airline asked customers to check Southwest.com for their flight status or to speak with a Southwest Airlines Customer Service Agent for further assistance.

Despite the ongoing issues, the flight-tracking website FlightAware showed dozens of Southwest trips underway as of Tuesday afternoon.

LOOK: Route 66’s quirkiest and most wonderful attractions state by state

Stacker compiled a list of 50 attractions--state by state--to see along the drive, drawing on information from historic sites, news stories, Roadside America, and the National Park Service. Keep reading to discover where travelers can get their kicks on Route 66.

READ ON: See the States Where People Live the Longest

Stacker used data from the 2020 County Health Rankings to rank every state's average life expectancy from lowest to highest. The 2020 County Health Rankings values were calculated using mortality counts from the 2016-2018 National Center for Health Statistics. The U.S. Census 2019 American Community Survey and America's Health Rankings Senior Report 2019 data were also used to provide demographics on the senior population of each state and the state's rank on senior health care, respectively.

Read on to learn the average life expectancy in each state.

The Most Influential Movies of the 21st Century