There have been rather large coronal holes on the Sun lately, as seen on this website:
https://solarmonitor.org/. Look at the middle image of the second row. This image is identified as "AIA 193Å 20180319 14:31". The 193 is the wavelength (in Angstroms), the 20180319 is today's date, the time 14:31 is Universal Time. The dark area in that image is a coronal hole, coronal holes are the source of high-speed solar wind, charged particles like electrons, protons, ions. At the moment, that coronal hole is pointed at us; therefore, the charged particles, when they arrive at Earth, can trigger a space-weather storm, which can result in aurorae.