Solar activity increased to high levels, due to an impulsive M6.1 flare at 04/1532 UTC, which originated from a source region behind the southeast limb. The presumed source is old Region 9866 (S09, L=191), which was an active flare producer on its last rotation, and is expected to rotate back into view within 24 hours. Other activity included an impulsive M1.4 flare at 04/1048 UTC from an evident source behind the southwest limb, and a C9.8 flare at 04/0442 UTC from a spotless plage region near S20E58, which was accompanied by a Type-II radio sweep (estimated velocity = 463 km/s) and a nearby disappearing filament. The CME activity associated with these events did not appear Earth-directed in SOHO/LASCO imagery. Most numbered regions on the visible disk appeared little changed from yesterday. Minor optical flares were observed in Regions 9885 (N13W39), 9888 (S12W06), and 9893 (N18E64).

Solar activity is expected to be predominantly low to moderate for the next three days. A chance for isolated major flare activity exists, in particular with the return of old Region 9866.

The geomagnetic field was quiet to unsettled. At 04/1335 UTC, the greater than 2 MeV electron flux exceeded event threshold at GOES-8 in geosynchronous orbit (75W). Flux levels remained above 1000 pfu for the remainder of the period.

The geomagnetic field is expected to be predominantly quiet to unsettled. A chance for some isolated active periods exists for days two and three of the forecast period, due to the possibility of some flanking shock passage effects from the CME events observed earlier today. Greater than 2 MeV electron flux is expected to persist at moderate to high levels for the next two to three days.

  Observé       04 Apr 216
  Prévisionnel   05 Apr-07 Apr  215/215/210
  Moyenne des 90 derniers jours        04 Apr 203

  Observé Afr/Ap 03 Apr  012/013
  Estimé     Afr/Ap 04 Apr  008/012
  Prévisionnel    Afr/Ap 05 Apr-07 Apr  008/010-012/012-010/010