My bad. I had assumed, as a part of the game, your "friend" was trusted enough to be telling the truth, working at high level NASA and all... I wouldn't know how you would positively verify the claim one way or another, unless you, coincidently, have an other "friend" that works in high level government position that would be privy to such information. You can't google it.... you'd get all kinds of BS
CME solar flare would probably knock out the power grid for a short while at the worst case, EMP pulse may knock out some electronics. All in all, the scenario wouldn't be too bad of a disaster, IMHO.
It would be at least 3 days before people, who don't prepare, start to panic and look for essentials, like drinking water.
Clean Water, IMO is the most important thing to stockpile, if advanced warning of any disaster is available.