As part of National Tsunami Preparedness Week, officials will conduct a test of the tsunami warning system in the coastal regions of central and southern California at approximately 10:15 a.m. PDT.

A National Oceanic and Atmospheric Administration (NOAA) release states, "Some television systems are programmed to scroll a standard emergency alert text message and in some cases, the message may not contain the word "TEST." An audio message will say that the message is only a test, but if the volume is turned down or otherwise unheard, viewers may not realize the message is a test."

The NOAA has mitigated potential for confusion by determining to cancel the test should any "excessive seismic activity" occur in the 24 hours leading up to the test.