Check out the link I sent you prior to this about weather briefing...
http://thefinerpoints.net/forum/viewtop ... light=EFAS
And then know that Enroute Briefing is available for you specifically through 122.0 and if you want to contact the FSS, you will have to determine the local FSS frequency from your chart and contact them through....."radio". Closing/opening flight plans and any other specific information that isn't contained in a route briefing--->use the FSS.
This service is there for you and truly is the best way to get up to date information. ATC is not responsible for relaying this information although in some situations they will if critical to safety of flight, ie a thunderstorms/wind shear etc