Forgive me for asking what I think is a basic question. I have programmed my 250d with the local S.A.M.E. code, and have turned the Weather Alert on. Does it stay on while I scan elsewhere? Or do I have to keep it listening to the weather frequencies for it to work? The instruction manual has left me more confused than anything. Any and all information regarding the 250d's weather alert will be greatly appreciated. Thanks in advance.