The best NOAA radios are designed specifically to receive alerts from NOAA as soon as they’re sent out, 24 hours a day, 7 days a week. They’re able to run without the use of an outlet in case a storm knocks out the power grid and often make use of integrated hand cranks and solar chargers to power the battery.
Aside from access to NOAA alerts, the biggest key to a great NOAA radio is its battery life. A smartphone is useful, but its battery won’t last longer than a day. Hand-crank radios will keep you apprised of your situation indefinitely.
Just use the crank to power your radio and keep yourself informed. This way, you can save your phone’s battery (and in many cases, replenish it) for more important uses like calling for help.