Categories Selected Articles Why Was the Tsunami Warning Issued, and Then Canceled? A Forecaster Explains. Post author By Mike Nova Post date December 5, 2024 The warning was sent in response to a 7.0-magnitude that struck off the coast of Northern California. A tsunami warning coordinator described the process. ← Tsunami warning: Was it a false alarm? → Earthquake-generated tsunamis not uncommon in US. How bad can they get and where do they hit?