Solar activity increased to moderate levels. Region 9733 (N14W36) remained the most active sunspot group on the disk. It produced two M-class flares: an M1/2N at 16/0124 UTC and an M1/1f at 16/0328 UTC. Minor radio emission accompanied both flares. Region 9733 decreased slightly in area and magnetic complexity and appeared to lose the magnetic delta configuration within its northernmost spots. However, it retained a moderately complex beta-gamma magnetic classification. Region 9739 (S13W43) appeared to be in a gradual growth phase, but remained simply structured. Region 9742 (N08E64) produced isolated subflares during the period. Magnetogram images suggest this region may possess a moderate degree of magnetic complexity, though it is difficult to gauge given its limb proximity. New Region 9743 (S10E73) produced isolated subflares as it rotated into view. It may represent the return of old Region 9714 (S08, L = 195), which produced M-class flares during its last rotation. New Region 9744 (S06E24) was also numbered.

Solar activity is expected to be moderate to high. Isolated, low-level M-class flares are likely. Region 9733 may produce a major flare during the period.

Geomagnetic field activity was at quiet to unsettled levels.

Geomagnetic field activity is expected to remain at quiet to unsettled levels. There will be a chance for a proton flare from Region 9733.

  Havaittu       16 Dec 209
  Ennusteet   17 Dec-19 Dec  205/200/195
  90 vuorokauden keskiarvo        16 Dec 219

  Havaittu Afr/Ap 15 Dec  010/011
  Arvioitu     Afr/Ap 16 Dec  010/012
  Ennusteet    Afr/Ap 17 Dec-19 Dec  010/010-008/008-008/008