WHETHER THE WEATHER
The fact is that it is not important which of two following possibilities are going to occur: Whether or not we really like it,
We use whether or not to indicate something is about to happen regardless of whether one ir the other is a true fact, and in this case NWS forecasters are saying both are.
USA TODAY says the majority of The United States of America will be getting some sun as temperatures begin to rise, while the first April storm develops.