Solar activity remained at moderate levels. Region 9455 (S17W52) produced an M1/Sf flare at 16/1042 UTC as well as isolated C-class subflares. Minor development was reported in the interior portion of this region, where a mild mix of polarities has persisted. Region 9454 (N13W08) also displayed a small degree of magnetic complexity, but was stable through the period. Region 9458 (S12W72) produced a C2/Sf flare at 16/1550 UTC as it approached the west limb. This flare was associated with a Type II radio sweep and a CME, which did not appear to be Earth-directed. Region 9461 (N16E63), which was the return of old Region 9433 (responsible for major flares during it previous two rotations), was relatively stable during the period. At present it is classed as a simple D-type group, but it is still too close to the east limb for a detailed analysis. No new regions were assigned.

Solar activity is expected to be at low to moderate levels with a fair chance for an isolated M-class flare from Region 9455. There is also a slight chance for an isolated M-class flare from Region 9454. At present, it is difficult to gauge the flare potential of Region 9461, given its proximity to the east limb. However, given its rich history of flare production, it cannot be counted out as a source for energetic flare activity.

Geomagnetic field activity ranged from quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.

The geomagnetic field is expected to be at mostly quiet to unsettled levels with a chance for active periods at high latitudes. The greater than 2 MeV electron flux may reach high levels during the first half of the forecast period.

  Osservato       16 May 138
  Previsto   17 May-19 May  145/150/155
  Media di 90 Giorni        16 May 167

  Osservato Afr/Ap 15 May  010/016
  Stimato     Afr/Ap 16 May  012/015
  Previsto    Afr/Ap 17 May-19 May  012/020-012/020-010/015