Solar activity increased to moderate levels. Region 9957 (N10W73) produced an M2/2f flare at 27/1810 UTC associated with minor discrete radio emission. Gradual decay may have continued in this region, but it was difficult to tell given limb foreshortening effects. However, it appeared that a weak delta persisted within its northern cluster of spots. Region 9961 (S22W30) produced isolated subflares as it continued to decay. Region 9970 (N05E41) appeared to stabilize as a simply-structured D-type spot group. Active surging and subflare activity was observed on the southeast limb near SE17. This limb activity may indicate the active return of old Region 9934 (S16, L = 211). A filament erupted from the northeast quadrant around midday. The eruption was associated with C2 X-ray event and a CME off the northeast limb. The CME did not appear to be Earth directed.

Solar activity is expected to be low to moderate. There is a fair chance for an isolated M-class flare during the period. There is a slight chance for a major flare as well.

Geomagnetic field activity increased to quiet to active levels with minor storm conditions observed at some high latitude stations. This activity was likely due to coronal hole effects. ACE solar wind data indicated a gradual rise in velocities during the period with peak velocities in the 700 to 800 km/sec range.

Quiet to active conditions are expected during the first half of the period. Quiet to unsettled conditions are expected during the remainder of the period. There is a slight chance for a proton event until 29 May.

  Observé       27 May 187
  Prévisionnel   28 May-30 May  180/180/180
  Moyenne des 90 derniers jours        27 May 183

  Observé Afr/Ap 26 May  009/010
  Estimé     Afr/Ap 27 May  017/025
  Prévisionnel    Afr/Ap 28 May-30 May  012/012-008/008-008/008