There are many different phone applications that offer "push" notification services during severe weather. Some are free, and some cost money. Depending on your particular preference, these apps can be downloaded to your smart phone or other device as a tool for weather warning information.
Be sure to enable the "push" notification feature, which allows the app to continuously poll for alerts, and set the alerts to an audible tone that will wake you up at night.
Here are a few examples of phone apps that offer push notification alerts for dangerous weather:
Many other applications are available for download via the Apple App Store or Google Play, and can be found by performing a simple 'Weather Radio' subject search.
Remember: Downloading a smartphone application is not a substitute to having a working weather radio.