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Moving Nest Stuck when inside corral_dist

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I have a TC simulation starting in the southern part of my domain, moving to the north. The child nest is centered on the storm to the south of the parent domain. It was a real head-scratcher why the nest was only moving east-west and not north-south. After ~36 hours as the TC moved north, it departed entirely from the child domain. Looking at the output, there were errors like "moad cannot move cancelling nest move in y" and the child grid "disp" kept increasing. I tracked it down to the default corral_dist=8 and my child nest is sitting at j_parent_start = 8. Apparently with the child nest sitting inside of the N-S corral_dist, it refused to move north as the storm moved north. Eventually the storm just left the child domain as it moved north, leaving the child domain behind.

I changed corral_dist = 2 and the nest tracks the TC appropriately now.

Here's a video showing the (fixed) nest_pos in the parent grid moving appropriately (the original just moves east-west and not north-south).

Not sure if this constitutes a bug, but it'd be nice if the code could ignore corral_dist if the nest was actually moving away from the corral boundary.


For moving nest, the parent domain is usually needed to be large enough, so that the child domain can move following the storm and avoid being too close to the parent domain boundary.
I agree it would be a nice feature if the code could ignore corral_dist if the nest is moving away from the corral boundary. Due to limited human power here, I am sorry to tell that this is not a priority for us at present.