Solar activity was at moderate levels. The largest event was a long duration M4/2n flare from Region 9733 (N14W10) at 14/1954 UTC. This event may have produced an earth-directed coronal mass ejection (CME) due to its near central meridian location. Images from the SOHO/LASCO spacecraft were not available at the time of this forecast. If an earth-directed, full-halo cme was created by this flare, its impact on earth would be approximately 40 to 60 hours from the time of origin. Region 9733 continues to maintain its size and magnetic complexity. Region 9727 (S21W77) also remained active during the period, producing one M-class flare and several optical subflares. An M3 flare with an associated Type II radio sweep (approx. velocity of 707 km/s), and an impressive CME was observed at 14/0913 UTC. The originating source appears to be just beyond the east limb as loop prominences were visible on the east limb at N06, from 14/0938 to 1035 UTC. The resulting CME is primarily eastward directed and should not be geoeffective. The noon Penticton 10 cm flux was estimated at 217 sfu as the actual measurement was enhanced due to the M3/2N flare.

Solar activity is expected to remain at moderate to high levels. Regions 9727 and 9733 are both capable of producing major flares. Region 9727 will rotate over the western limb on 15 December. The region that produced the M3 flare and CME should rotate onto the disk during the first day of the forecast period.

The geomagnetic field was quiet.

The geomagnetic field is expected to be at quiet to unsettled conditions early on the first day. Active conditions are expected late on the first day and into the second day. These active conditions will be caused by a glancing blow from a CME that originated from an X6/3b flare on 13 December. Conditions should return to quiet to unsettled levels on day three.

  Observé       14 Dec 217
  Prévisionnel   15 Dec-17 Dec  220/210/200
  Moyenne des 90 derniers jours        14 Dec 218

  Observé Afr/Ap 13 Dec  004/004
  Estimé     Afr/Ap 14 Dec  004/005
  Prévisionnel    Afr/Ap 15 Dec-17 Dec  015/015-025/025-015/010