Solar activity dropped to low levels. Region 9433 (N17W50) produced isolated C-class flares, the largest of which was a C7/1f at 28/0934 UTC. Gradual decay continued in the leading and intermediate portions of this region. However, no decay was evident within its trailing spots, where a strong magnetic delta configuration remained. Region 9441 (N07E23) continued a gradual growth phase that began on 27 April, but the region remained a moderate-sized, simply-structured bipole. New Regions 9444 (S11E67) and 9445 (N23E76) were assigned.

Solar activity is expected to be at moderate to high levels. Region 9433 is expected to produce isolated M-class flares. This region could also produce an isolated major flare during the period.

Geomagnetic field activity ranged from quiet to minor storm levels. An interplanetary shock at the leading edge of a CME passed the ACE spacecraft at 28/0432 UTC, followed by a sudden impulse (SI) at 28/0520 UTC (76 nT, as measured by the Boulder USGS magnetometer). The source for the CME was an M7/2b flare on 26 April. Field activity increased to unsettled to minor storm levels following the SI. The greater than 10 MeV proton flux at geosynchronous orbit briefly crossed event threshold in response to the shock passage. The greater than 10 MeV event began at 28/0430 UTC, reached a maximum of 57 PFU at 28/0500 UTC, then ended at 28/0520 UTC. Proton fluxes had decreased to near background levels by the close of the period.

Geomagnetic field activity is expected to be at unsettled to active levels through midday, 29 April as the disturbance gradually subsides. Quiet to unsettled levels are expected for the remainder of the period. Region 9433 could produce another proton flare before it crosses the west limb on 02 May. The greater than 2 MeV electron flux at geosynchronous orbit may reach high levels during the first half of the period.

  Observed       28 Apr 188
  Predicted   29 Apr-01 May  185/180/175
  90 Day Mean        28 Apr 167

  Observed Afr/Ap 27 Apr  003/006
  Estimated     Afr/Ap 28 Apr  026/028
  Predicted    Afr/Ap 29 Apr-01 May  015/015-012/010-010/010