Solar activity decreased to moderate levels. Region 338 (N18W85) produced an M2.5/Sf at 26/2340Z and an M1.7/Sf at 27/1532Z which were the largest flares of the period. This region was again responsible for the vast majority of the activity observed today. Proximity to the west limb hinders analysis of changes in magnetic structure today. Region 344 (N16W00) showed slight growth today and retains a beta-gamma-delta structure. The weak delta complex is evident in the northwestern quadrant of the dominant trailing spot. Region 337 (S14W40) underwent rapid growth during the period adding many additional spots to the south of the main body of this group. This region also depicts a beta-gamma-delta magnetic structure. A 34 degree solar filament erupted yesterday at approximately 26/2000Z which resulted in a streamer CME that does not appear as though it will become geoeffective No new regions were numbered today.

Solar activity is expected to be at moderate levels. Region 338 has begun to transit the disk but remains capable of producing a major flare.

The geomagnetic field was at quiet to active levels. An increase of 150 km/s in the solar wind speed during the period is believed to be the result of a recurrent coronal hole. The greater than 2 MeV electron fluxes at geosynchronous orbit reached high levels again today.

The geomagnetic field is expected to be at predominantly unsettled to active levels through the interval. High latitude minor storm conditions are possible on day one and into day two due to a favorably positioned coronal hole.

  觀測的       27 Apr 154
  預測的   28 Apr-30 Apr  155/160/155
  90天平均值        27 Apr 127

  觀測的 Afr/Ap 26 Apr  009/015
  估算值     Afr/Ap 27 Apr  012/012
  預測的    Afr/Ap 28 Apr-30 Apr  015/015-012/015-012/015