http://www.newsweek.com/solar-flare-cme-space-weather-1748427

A series of strong solar flares erupted from the sun on Saturday and Sunday, and the ejected material is set to cause a geomagnetic storm on October 4.

One of the flares was so strong that it may have caused a high-frequency radio communication blackout over a wide area for about an hour on Sunday afternoon, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC).