As early as the end of this month, NOAA should have a much better idea of just how dangerous those electromagnetic storms are. The agency will begin releasing forecasts that use a more sophisticated model to predict how incoming solar storms could fry electrical power grids. It will be the clearest guide yet as to which utility operators, in what parts of the world, need to worry.
http://www.nature.com/news/us-sharpens-surveillance-of-crippling-solar-storms-1.20630
