I use our smart phone and create a list of weather locations for a number of towns/cities we plan to drive thru. I then can get the forecast, weather conditions and/or alerts for that location in about 5 seconds and get an immediate up to date.
It works very well, fast and always up to date.
My wife has a function on her phone that works on any phone; she does not have a smart phone. It gives you info much like a computer without having anything but a normal cell phone and works anywhere you have phone service.
She dials Bing at 800 246 4411, says "weather", gives the city and state, like Charleston, SC or you can simply give a zip code. They give the weather and a forecast. It is not limited to simply weather.
She read about this in the Escapee magazine, one of the best RV magazines.