Near X-class solar flare reaching M9.3 erupted from departing Sunspot 1996 on March 12, 2013 at 22:34 UTC.
This decaying sunspot is located near eastern limb and generated CME was not geoeffective, however, it produced a R2 (Moderate) Solar Flare Radio Blackout which can cause limited blackout of HF radio communication on sunlit side, loss of radio contact for tens of minutes and degradation of low-frequency navigation signals for tens of minutes.
SDO's AIA 194 and EVE captured powerful M9.3 solar flare at 22:43 UTC on March 12, 2014. (Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams)
The minor geomagnetic storm at high latitude was caused by a fluctuation in the interplanetary magnetic field when Bz component of the interplanetary magnetic field (IMF) tipped south early on March 13, 2014, opening a crack in Earth's magnetosphere. NOAA/SWPC reported minor G1 Geomagnetic Storm Level.
Weak power grid fluctuations can occur with possible minor impact on satellite operations. Auroras are reported around the Arctic Circle.
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2014 Mar 13 0218 UTC
Synoptic Period: 0000-0300 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
Red and green aurora display seen from Inari, Finland late on March 12, 2014. (Credit: Rayann Elzein/via SpaceWeather.com RealTime Aurora Gallery)
Featured image: SDO's AIA 304 image taken at 22:38 UTC on March 12, 2014. (Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams)