SAN DIEGO — Southwest Airlines experienced more issues with its system Tuesday, leading to long lines at the airport in San Diego.

Southwest Airlines passengers saw flight disruptions on Monday after the airline attributed an issue with its system to a third-party weather data provider. Operations resumed Monday night after the technical difficulty was reported nationwide.

On Tuesday, Southwest said on Twitter that it was working to fix more issues. The airline said in a 12:50 p.m. update that flights were disrupted throughout their network.

“We are in the process of resuming normal operations after a system issue this afternoon that created flight disruptions throughout our network. We know many customers still require assistance and are working to address those concerns as quickly as possible,” the airline said on Twitter.

Southwest said customer service wait times were expected to be longer than normal and suggested passengers visit their website to explore self-service options.

Officials at the San Diego International Airport urged Southwest passengers to check with the airline before coming to the airport, where long lines were seen both inside and outside the building.

Check back for updates on this developing story.