Solar activity was at very low levels again today. Region 582 (N14W51) continues to decay and has lost all penumbral area in the trailing polarity of the region. Region 587 (S13W03) has showed a slight decay since yesterday. Region 588 (S12E51) underwent a little growth and currently has sunspots of opposite polarity to the solar south of the dominant sunspot. No new regions were numbered today.

Solar activity is expected to be at very low to low levels.

The geomagnetic field ranged from quiet to minor storm levels. The onset of a shock occurred at the ACE spacecraft at approximately 03/0849Z. Preliminary review indicates that there was a magnetopause crossing of the GOES 12 satellite between 03/1630 and 1730Z. Interestingly, a sudden impulse which was measured as 14 nT on the Boulder magnetometer occurred at 03/1414Z. The transient may have been related to the full halo coronal mass ejection (CME) that occurred on 31 March. Due to the SOHO/LASCO spacecraft maneuvers that were in progress at the end of March (no images were being retrieved) there is little certainty at this time as to whether this shock passage was the result of the full halo CME or related to other activity that preceded the long duration C3 event. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

The geomagnetic field is expected to be at predominantly active levels for 4-5 April. During the first two days, isolated minor storm conditions may persist especially in the nighttime sectors, due to the potential of further transient activity, and the likelihood of a recurrent co-rotating interaction region. Major storm levels are expected due to a strong recurrent high speed coronal hole stream that is due to become geoeffective on 6 April.

  Observé       03 Apr 107
  Prévisionnel   04 Apr-06 Apr  105/105/100
  Moyenne des 90 derniers jours        03 Apr 111

  Observé Afr/Ap 02 Apr  003/003
  Estimé     Afr/Ap 03 Apr  015/023
  Prévisionnel    Afr/Ap 04 Apr-06 Apr  015/020-015/020-025/035