I wanted to find out if subcritical flow could become supercritical going around the 32 degree bend of Cape Mendocino. For subcritical upstream flow and a wide channel, I chose 10 km as the radius of curvature of the Cape Mendocino bend and used Chow's formula. The speed and depth before the flow reached the bend is shown by the purple lines. For higher Fr upstream or sharper bends, the depth of the flow near the wall can become negative. Supercritical flow also thins and accelerates around a bend, with jumps possible.
Jumps develop off of the outer wall which turns inward on the flow.
The inner wall which turns away from the flow sends out an expansion fan. This flow arises because centripetal acceleration is constant through the layer, but friction near the bottom reduces the Coriolis force, creating a toward-bend flow at the bottom and a compensating flow away from the bend above.