I don't monitor any of the systems in the metro area, but I will take a GUESS that was an emergency alarm. I don't know if you are seeing the complete RID (I assume that is RADIO ID), it should be 7 digits. like 2618208. The first two digits are the county, next is the service, next is radio type and the last three are the radio ID. 2618208 would be a Police Console. It does not make sense that a console would send an emergency alert, normally that would just be from subscribers. It could also be the target ID. Again, I don't monitor or work and any of the radios on Portland's system.