There will be a test of the Indian Point sirens in Westchester, Rockland, Putnam and Orange Counties on Wednesday, November 2nd, at approximately 10:30AM.
This sounding is only a test. If there were an emergency at the nuclear power plants, the sirens would be sounded continuously at full volume for 4 minutes, followed
by an activation of the Emergency Alert System (EAS) on radio and television stations to broadcast important information and instructions.
The sirens are not a signal to evacuate. Rather, they are intended to alert the public to tune to an EAS radio or TV station for important information.
The siren sounding is ONLY A TEST. No action by the public is necessary.
Original source can be found here.