"When an event occurs that requires that a restriction or limitation be placed on air traffic overhead the FAA, upon the request of a public entity, can put a temporary flight restriction (TFR) in place. There is a rule that describes the circumstances and authority, Airspace Restrictions [Note the section on Temporary Flight Restrictions ] The dissemination of the information is most effectively accomplished via apps like foreflight and skyvector.com but those are not official sources."
I also believe that you need to use your own social media channels and media contacts to get the word out. Not everyone is tuned into the official flight channels, so use every outlet you can find.
Note: Charlton will the main speaker on the CRDR Drone Webinar: Steps to Establishing a Drone Program. Take time and register now! I do like the title of "Professional Micro Aviation" as a way to eliminate the word "drone" from an otherwise polarizing word in some circles today.