Reverse 911
If you haven't already done so, you may want to register your cell phone or voip phone with the Reverse 911 system. I don't know how many counties have implemented this system, but San Diego County is making good use of it during the current fire crisis. To receive notifications on a cell or VoIP phone, you have to register your home address with the system. Here is the link
Reverse 911®
Emergency Notification SystemThe Emergency Notification System allows the City to rapidly send telephone notifications to all residents and businesses in an affected area in the event of an emergency. An operator using the system can identify the affected neighborhood or region of the city and record a message that describes the situation. The system will automatically call listed and unlisted telephone numbers (including TTY/TDD) within the affected area and deliver the recorded message. If phone lines are busy, the system will attempt to redial those telephone numbers to make contact. If an answering machine picks up the call, the emergency message will be left on the machine.