For this you would need something like a GPS and a processor to perform a lookup of a local SAME code geographic database to program the Radio receiver to tune to the correct Station frequency (1 of 7 frequencies) broadcast automatically. I don't think that there are any portable NOAA radios that currently do this even though it would be easy to implement.

The same problem occurs with FM radio station fading as you move from one transmitter to another. Perhaps if something like DAB (Digital Audio Broadcast) were implemented the USA a cheaper receiver circuit without the requirement for a GPS tracker could be implemented for a mobile automatic NOAA NWR system in the future.

I seem to remember that there were some moves to implement the EAS system on all future Cellular Phone handsets so the government can keep track of your location so that a POTUS message can be sent to those just before they perish in a SHTF event. I believe that the NWR is a subset of the EAS system.