While I do use my smart phone don't get in the habit if trusting it. To many possible problems ie. reception and batteries to name a few. I need to get a small weather radio. This some of this are pretty small and weigh very little. Another thing that is useful is a barometer. You can get this made into electronic weather stations that are about the size of a GPS. Or you can used the method that I use. I watch the clouds a great deal and notice things like wind speed, direction, and temps. When there are certain types of clouds present and one or more of the other things start changing quickly I know I am in for some potentially rough times.