Solar activity increased to moderate levels. An M1 X-ray flare peaked at 21/2157 UTC associated with moderate discrete radio bursts and a Type II radio sweep (estimated velocity 740 km/sec). LASCO/EIT images indicated that Region 9591 (S17E63) was the source for this flare. It was also the likely source for an M1 X-ray flare that peaked at 22/1216 UTC. This region also produced occasional, impulsive low- to mid-level C-class flares during the period. Region 9591 continued to rotate into view as the day progressed and is now classed as a moderate-sized F-type spot group. Limb proximity prevented a detailed analysis of this region's magnetic structure, but recent activity suggests at least a moderate degree of magnetic complexity. No remarkable changes occurred in the remaining active regions, including newly numbered Region 9592 (S09W59).

Activity is expected to be moderate with a good chance for isolated M-class flares from Region 9591. There is also a slight chance for a major flare from this region.

Geomagnetic field activity was at quiet to unsettled levels until 22/0300 UTC, then increased to unsettled to active levels for the remainder of the period. This activity was due to a high-speed stream associated with a recurrent, negative-polarity coronal hole.

Geomagnetic field activity is expected to be at unsettled to active levels through the period. There will be a slight chance for a proton event during the period. The greater than 2 MeV electron flux at geosynchronous orbit may reach high levels during the first half of the period.

  Havaittu       22 Aug 162
  Ennusteet   23 Aug-25 Aug  170/175/180
  90 vuorokauden keskiarvo        22 Aug 151

  Havaittu Afr/Ap 21 Aug  012/014
  Arvioitu     Afr/Ap 22 Aug  016/018
  Ennusteet    Afr/Ap 23 Aug-25 Aug  015/012-012/010-015/012