Solar activity has been at low levels for the past 24 hours. Region 1386 (S18E08), Region 1387 (S21W70) and New Region 1389 (S20E70) have all produced C-class events, the largest being from Region 1389, which was a C7/1F flare at 1425Z. Region 1386 and 1387 both continue to grow and evolve, but have yet to produce major solar activity. Several small non-Earth directed CMEs were observed during the summary period.

Solar activity is expected to be at low to moderate levels for the next three days (29 - 31 December).

The geomagnetic field has been at quiet levels for the past 24 hours. Signatures observed by the ACE spacecraft indicate the arrival of a small CME around 0950Z. Solar wind speeds increased from around 250 km/s to 280 km/s with and increase in the total IMF to around 14 nT. This transient appears to be from an unknown event, perhaps on 24 December. The lower energetic particle sensors on the ACE spacecraft continue to gradually increase, indicating another approaching CME.

The geomagnetic field is expected to be at quiet to active levels with a chance for isolated minor storm levels on day one (29 December) as multiple CMEs are expected to arrive. Quiet to unsettled level are expected on day two (30 December) as effects the previous CMEs wane. Predominantly quiet levels are expected on day three (31 December).

  觀測的       28 Dec 145
  預測的   29 Dec-31 Dec  145/140/140
  90天平均值        28 Dec 144

  觀測的 Afr/Ap 27 Dec  002/001
  估算值     Afr/Ap 28 Dec  003/004
  預測的    Afr/Ap 29 Dec-31 Dec  015/022-012/012-005/005