An interplanetary shock wave possibly associated with the M5-class solar flare of May 17th swept past Earth on May 20th around 02:00 UTC according to SpaceWeather. The shock's arrival caused geomagnetic activity around the poles, and several outbreaks of high-latitude auroras. Click the following LINK to watch the latest CME forecast model run.
3-day Solar-Geophysical Forecast issued May 20 22:00 UTC by NOAA/SWPCSolar Activity Forecast: Solar activity is expected to be at predominately low levels for the next three days (21 - 23 May). A slight chance for M-class activity exists all three days.
Geophysical Activity Forecast: The geomagnetic field is expected to be at predominately quiet levels for day one (21 May). By days two and three (22 - 23 May), quiet to unsettled levels with a slight chance for isolated active periods are expected due to coronal hole high speed stream effects coupled with the arrival of the 18 May CME.
Featured image: Aurora display seen over Edmonton, Alberta, Canada on May 20, 2012 (Credit: Matt Melnyk)