Solar activity was low with several minor C-class flares observed throughout the period. Region 119 (S14E04) exhibited considerable growth and was responsible for majority of the C-class flares. Renewed complexity developed in Region 105 (S09W70) and occasional C-class flares were observed. White light areal coverage still exceeds 500 millionths in this moderately complex beta-gamma region. Active Region 114 (S11W57) showed significant decay over the last 24 hours. New Regions 124 (N03W49) and 125 (S08E69) were numbered today.

Solar activity is expected to be low to moderate. Best chance for an isolated M-class flare is from developing Region 119 or Region 105 as it approaches the west limb.

The geomagnetic field was mostly quiet to unsettled with isolated active periods. The disturbed conditions are due to the elevated solar wind speed (550 km/s).

The geomagnetic field is expected to continue at mostly unsettled levels with isolated active periods. Active to minor storm conditions are expected on the latter half of day one due to the C8 flare and partial halo CME that occurred early on 17 Sep. Expect conditions to return to unsettled levels as the expected storm subsides on day two.

  觀測的       18 Sep 177
  預測的   19 Sep-21 Sep  175/165/160
  90天平均值        18 Sep 178

  觀測的 Afr/Ap 17 Sep  011/013
  估算值     Afr/Ap 18 Sep  013/014
  預測的    Afr/Ap 19 Sep-21 Sep  015/020-015/015-008/012