Solar activity was low. A long-duration C4 flare began at 1544 UTC and lasted until 1919 UTC. The corresponding source on the disk was not entirely certain but it seemed most likely to be correlated to activity observed in Region 9866 (S08W73). Additional C-class subflares occurred during the day, with many of these coming from Region 9875. Region 9875 showed steady growth during the past 24 hours. Three new region were assigned today: 9876 (S16E65), 9877 (N18W29), and 9878 (N08E75).

Solar activity is expected to be low to moderate during the next three days.

The geomagnetic field was quiet until 1329 UTC when a sudden impulse (SI) occurred. Since then the geomagnetic field has ranged from quiet to active levels. The SI was caused by an interplanetary shock which was seen at the ACE spacecraft at 1307 UTC. The disturbance is most likely the result of the halo CME was observed in LASCO C2 at 18/0254 UTC. The shock also pushed the greater than 10 MeV proton fluxes up to about 19 PFU at 1525 UTC. The proton event fluxes dropped below event level at 1820 UTC.

The geomagnetic field is expected to be mostly unsettled for the next three days. There is a chance for some isolated active levels on the second day as a possible response to yesterday's partial halo CME.

  觀測的       20 Mar 188
  預測的   21 Mar-23 Mar  175/170/165
  90天平均值        20 Mar 213

  觀測的 Afr/Ap 19 Mar  015/017
  估算值     Afr/Ap 20 Mar  010/010
  預測的    Afr/Ap 21 Mar-23 Mar  010/010-015/015-010/008