The National Oceanic and Atmosphere Administration has warned of X class solar flares. Hear about it at Urban Legends and Stranger truths. The strongest category of solar flares known to potentially cause worldwide transmission problems and blackouts could be emitted over the next couple of weeks, and one of them could be a radio blackout that we've already detected, though scientists can't say where the warning comes from. The scientists from both the US. And Russia. The latter from Moscow's. Federov Institute of Applied Geophysics