The Sun Online and solar activity. May 21, 2014

There were two C flares during the past 24 hours. The brightest flare was a C2.3 flare released by NOAA AR 12071, peaking at 01:38 UT on May 21. LASCO C2 and C3 and STEREO COR2 A and B observed a bright CME probably associated to this flare. There is a slight chance for a glancing blow from this CME on May 24. In the next 48 hours, more C flares are likely, especially from NOAA AR 12071, 12072, and 12066.Over the last 24 hours, solar wind speed as observed by ACE gradually declined from 350 to 320 km/s, while the
magnitude of the Interplanetary Magnetic Field (IMF) varied between 2 and 5 nT. Over the past 24 hours, geomagnetic conditions were quiet (K Dourbes between 0 and 2; NOAA Kp between 0 and 1). Quiet geomagnetic levels (K Dourbes < 4) are expected on May 21 and 23. As an effect of an expected sector boundary crossing to a negative phi angle (toward) and the high speed stream associated to a weak southern coronal hole, there is a chance for active geomagnetic conditions (K Dourbes = 4) on May 22.