A turbine exhaust diffuser for a gas turbine engine. The diffuser includes a flow ramp positioned on an ID flowpath boundary within a flowpath of the diffuser. The flow ramp extends circumferentially about the hub and includes a downstream, radially outward point that extends radially outward further from the ID flowpath boundary than an upstream, radially outward point that is positioned upstream from the downstream, radially outward point. A wavy portion is located at the downstream, radially outward point of the flow ramp. The wavy portion includes a circumferentially extending, undulating surface defined by alternating axially extending crests and troughs.