Southwest Airlines said today it plans to initially fly nonstop to Hawaii from four cities in California — Oakland, San Diego, San Jose and Sacramento.

The Dallas-based carrier made the announcement after disclosing late Wednesday afternoon it would offer interisland service possibly within a year after beginning its mainland-Hawaii flights.

“The way we plan to serve Hawaii requires us to share these initial details now so that our facilities in the airports will be ready for all that we intend to offer,” Southwest President Tom Nealon said. “We’re on track with our plans to sell tickets this year and are respectfully engaged in the process to receive FAA authorization to operate between the mainland and the islands.”