Joe Kunches wrote an article, 5 May 2015, for the Washington Post titled Scientists spot evidence for ‘superflares,’ blowing away anything we’ve ever seen. The premise of the article was that the sun could unleash a flare of such a magnitude that it would dwarf anything humans have ever observed.
A "superflare" is a solar flare that contains energy 1,000 times larger than what has been observed in modern times.
Solar flares are known to cause blackouts of radio communications on the sunlit side of the Earth and disrupt radio navigation services. They provide the energy for a class of energetic particle acceleration that results in solar radiation storms that can disturb or damage satellites. They are also sometimes associated with geomagnetic storms that, if severe enough, can disturb the Earth’s electrical grid.
The article suggested that a superflare, off-the-charts of our current space weather classification system, should occur about once every 800-5,000 years.
Joe Kunches is based in Boulder, Colo., and was a former lead forecaster and operations chief at NOAA's Space Weather Prediction Center.