The wireless industry, The FCC and FEMA will roll out the WEA's (Wireless Emergency Alerts) system nationwide this year. The NWS will start utilizing this by pushing extreme weather warnings over the system in June 2012. Tornado Warnings, Flash Flood Warnings and several other high-end warnings will go directly to wireless users in an affected county automatically if their device is capable. The following statement is from the National Wather Service:
If you have a cell phone, it may soon make some curious sounds and vibrations the next time you find yourself in the possible path of a tornado or several other types of weather emergencies.
Starting any day now, the Wireless Emergency Alerts (WEA) system will go live. That means the National Weather Service (NWS) warnings for dangerous weather, including tornadoes, flash flooding and huricanes, will be delivered free of charge to many mobile users on major wireless carriers. Tha alerts will look like text alerts, but use different technology that is not affected by network congestion.
The WEA system is "location-based", which means that you only receive alerts relavent to your physical location. In other words, if you travelto another city, you'll receive alerts for where you are, not back home.
AMBER Alerts and Presidential Alerts during a notional emergency will also be delivered through the WEA system. If you have a WEA-capable phone, you'll receive alerts unless you opt out (you can't opt out of Presidential Alerts, however). Interestingly, the alerts will *not* interupt phone conversations, but rather will be dalayed until a call is finished.
You can visit the Wireless Emergency Alerts page here to read more about it, and follow links to see if your device is capable of receiving these alerts