Solar activity was moderate. Region 672 (N05W58), which has been in a decay phase over the last 72 hours, produced two notable events this period. The first was an extended C3.8 flare at 19/1148Z that erupted along a filament channel just north of the spot cluster. The second was an M1.9 flare at 19/1712Z. This impressive flare had associated Type II (604 km/s) and Type IV radio sweeps; a 520 sfu Tenflare, and a greater than 10 MeV proton event. LASCO imagery was unavailable. Region 672 is a C-type beta spot group with under 100 millionths of white light area coverage. Region 673 (S13E22) showed little change this period and continues to produce occasional B-class flare activity.

Solar activity is expected to be low to very low. There is a small chance of another M-class flare from Region 672 before it rotates around the west limb early on 22 September. Occasional C-class flares are possible from Region 673.

The geomagnetic field was quiet. Solar wind speed was generally below 400 km/s. A greater than 10 MeV proton event followed today's M1 flare at 19/1712Z. The proton event began at 19/1925Z and was still in progress at the time of issue. The maximum flux value so far was 35 pfu at 19/2025Z. A greater than 100 MeV proton flux enhancement was also observed, but has not exceeded the 1 pfu event threshold. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels.

The geomagnetic field is expected to remain at mostly quiet to unsettled levels on 20 and 21 September. A disturbance associated with today's M1 flare and CME is expected to occur on 22 September: Active to minor storm periods are likely. The greater than 10 MeV proton event in progress now is expected to end by 21 September.

  觀測的       19 Sep 105
  預測的   20 Sep-22 Sep  100/095/090
  90天平均值        19 Sep 112

  觀測的 Afr/Ap 18 Sep  016/016
  估算值     Afr/Ap 19 Sep  005/008
  預測的    Afr/Ap 20 Sep-22 Sep  005/008-008/012-015/020