Southwest has announced plans to start service to Minneapolis – St. Paul International Airport (MSP) in March ‘09. The only route that has been announced so far is to Chicago Midway, but this is clearly an attack on Northwest and a pretty big bet on Delta scaling back MSP service in the coming months after the Delta/Northwest merger closes.

Considering the success Southwest has had in Denver going after United and Frontier, I am going to bet on them succeeding rather well on this bet. The biggest risk they face is Northwest/Delta getting into a pricing war and trying to undercut the fares and beat them out of the market. Prior to the merger Northwest would have never let it happen without a serious fight. But with Delta taking over this will just be a good excuse to show “lower demand for flights” and make “appropriate adjustments in the service frequencies” in Minneapolis.

This will be great for passengers there as long as Southwest ramps up service commensurate with demand, which I think they will do. They certainly have the fleet and route network available to do so.