Each memory channel can be included or excluded from the Scan list.
For example, if you program-in your local Weather Radio frequency into memory channel 199 (for example), then you can 'lock out' memory 199 from the active scan list so it won't be heard while scanning memories.
The Scan indicator is the tiny little "S" in the bottom right of the display (easy to miss if you don't read the manual).
Use F+MR to alternate the setting on a per-memory basis. 'S' will be scanned. No 'S' will lock-out that particular memory channel.
ALSO WORTH NOTING:
This radio uses the stop, listen and proceed method of scanning. In other words, it stops on the busy channel for about four or five seconds, then takes off scanning again even if the conversation was interesting. You have to reach over and press PTT (escape) on the next go-around if you wish to listen to a particular conversation.
It scans, but it's not a good VHF/UHF scanner.
I'm not sure exactly how many channels per second it covers, but about 5 per second. If all 200 memories were programmed and scanned, it would be a poor scanner since the go-around time would be so long that you'd miss too much.