If you live in the coastal areas of the county, the sirens you hear today and tomorrow are Diablo Canyon nuclear power plant "growls."

The sirens are part of an "early warning system" that were installed as part of Diablo's operating requirements. The sirens cover an area from Cayucos to the north to the Nipomo Mesa to the south.

Any questions about the tests can be directed to the county Office of Emergency Services at 781-5011.