Solar activity increased to moderate levels. Region 9455 (S17W38) produced an M1/1n flare at 15/0300 UTC associated with Type II and IV radio sweeps and a CME, which did not appear to be Earth-directed. Region 9455 showed no significant changes and maintained a minor degree of magnetic complexity. Minor spot development occurred within Region 9454 (N12E05), which also possessed minor magnetic complexity. New Region 9461 (N15E76) rotated into view. It appeared to be the return of old Region 9433, which produced major flares during its previous two rotations. An impressive eruptive prominence and associated CME occurred from beyond the northeast limb (to the east of new Region 9461) late in the period. A long duration C-class X-ray enhancement was associated with the prominence eruption.

Solar activity is expected to be at low to moderate levels. Regions 9455 and 9454 appear capable of isolated M-class flare activity.

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

Geomagnetic field activity is expected to be at quiet to active levels. The greater than 2 MeV electron flux is expected to reach high levels during the first half of the period.

  Observé       15 May 142
  Prévisionnel   16 May-18 May  150/160/170
  Moyenne des 90 derniers jours        15 May 167

  Observé Afr/Ap 14 May  010/012
  Estimé     Afr/Ap 15 May  014/015
  Prévisionnel    Afr/Ap 16 May-18 May  012/015-012/020-010/015