Solar activity was low. Region 9269 (N11W06) produced today's largest flare, a C7/Sf at 1111Z. The event was associated with a relatively slow, full-halo coronal mass ejection as observed by LASCO imagery. An additional CME occurred, beginning with the lift-off of a portion of the southern polar crown filament (near S50E01) at 1824Z. The remainder of today's activity consisted of numerous C-class events from a variety of regions, including Region 9278 (N09E51) which has rotated more clearly into view as a D-type sunspot group. New Region 9279 (S11E62) was assigned today.

Solar activity is expected to be low. There is a slight chance, however, for an isolated M-class event from any of regions 9264 (S25W36), 9267 (N08W57), 9276 (S12W85), or 9278 (N09E51).

The geomagnetic field was quiet to unsettled during the past 24 hours.

The geomagnetic field is expected to be mostly unsettled for the next two days. An increase to active, with a possibility for minor storm levels, is expected on the third day, in response to today's halo CME event.

  觀測的       18 Dec 198
  預測的   19 Dec-21 Dec  195/195/190
  90天平均值        18 Dec 176

  觀測的 Afr/Ap 17 Dec  006/008
  估算值     Afr/Ap 18 Dec  008/010
  預測的    Afr/Ap 19 Dec-21 Dec  010/010-010/010-025/030