Nixle is an emergency alerting system used by the Santa Clara County area. Simply sign up via your phone. Text 888777 and "OPT-IN", it will then prompt you for your zip code to start receiving alerts. More info can be found here http://www.nixle.com/
AlertSCC is a free, easy, and confidential way for anyone who lives or works in Santa Clara County to get emergency warnings sent directly to their cell phone, mobile device, email, or landline. AlertSCC can reach you wherever you are to provide information and instructions in a variety of emergency situations, which may include:
Flooding, wildfires and subsequent evacuations
Public safety incidents, including crimes, that immediately affect your neighborhood
Post-disaster information about shelters, transportation, or supplies
[https://www.sccgov.org/sites/alertscc/] Also search for the app in your smartphone's app store.
Santa Clara County can receive continuous alerts . Tune your radio to the following stations which do not require a special radio to listen.
1680 AM - updates on which areas emergency responders are responding to such as injury, damage, fire and electrical hazards etc
KCBS-AM 740
KGO-AM 810
KQED-FM 88.5
KSOL-FM 98.9 [Spanish]
KSJX-AM 1500 [Vietnamese]
NOAA Weather Radio All Hazards (NWR) is a nationwide network of radio stations broadcasting continuous weather information directly from the nearest National Weather Service office. NWR broadcasts official Weather Service warnings, watches, forecasts and other hazard information 24 hours a day, 7 days a week. [https://www.nws.noaa.gov/nwr/]
You can find a few options here for weather radios on Amazon
In an emergency and power is available and you have an antenna, turn on the TV. The Emergency Alert System (EAS) is a national public warning system that requires broadcasters, satellite digital audio service and direct broadcast satellite providers, cable television systems, and wireless cable systems to provide the President with a communications capability to address the American people within 10 minutes during a national emergency. [ready.gov]
EAS FactSheet: www.fema.gov/about/news-multimedia/fact-sheets
Wireless Emergency Alerts (WEA) are emergency messages sent by authorized government alerting authorities through your mobile carrier. [FEMA]
Check with your phone and carrier for support.
Find out more here: https://myshake.berkeley.edu/about-us.html