National Test of the Alert & Warning Systems tomorrow morning. 
On Wednesday October 3, 2018, the Federal Emergency Management Agency (FEMA), in coordination with the Federal Communications Commission (FCC), will conduct a nationwide test of the Wireless Emergency Alerts (WEA) and Emergency Alert System (EAS). The WEA portion of the test commences at 11:18 am and EAS portion follows at 11:20 am. The test will assess the operational readiness of the infrastructure for distribution of a national message and determine whether improvements are needed.
The WEA test message will have a header the reads “Presidential Alert” and the test that says; “THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed”. The test message is not from the President of the United States or is it managed by Marin County.
You can’t opt out of the alerts, as it is a Federal law that all cellular phones with data plans must broadcast these Federal alerts. We just wanted to give you warning, so you are not caught by surprise tomorrow morning.
Additional information: https://www.fema.gov/emergency-alert-test
Address/Location
County of Marin Office of Emergency Management
1600 Los Gamos Dr
San Rafael, CA 94903
Contact
Emergency: 9-1-1
Non-emergencies: 415-479-2311