Solar activity has been high. Region 9906 (S14W90) produced a long-duration X1/1f flare at 0151 UTC which was accompanied by strong radio bursts, type II and type IV radio sweeps, and a partial halo CME. The CME moved extremely rapidly in the plane of the sky with a projected velocity of 2400-2500 km/s. The front of the CME appeared to be moving away from the west limb and therefore approximately perpendicular to the line of sight. The remainder of today's activity consisted of a few C-class events. A filament was observed to lift off the northeast part of the disk at 21/0012 UTC and was associated with a narrow CME from the northeast limb. Region 9912 (N10W12) has continued to grow and is currently the largest group on the disk now that 9906 has rotated behind west limb. 9912 was stable and quiet. Two new regions were assigned today: 9915 (N11E54) and 9916 (S17E71).

Solar activity is expected to be low to moderate. Region 9906 could contribute an M-class event during the next 24 hours, but will become less of a threat as it moves further behind the limb. There is a slight chance for an isolated M-class event from Region 9912.

The geomagnetic field was quiet to unsettled during the past 24 hours. A greater than 100 MeV proton event began at 21/0155 UTC in response to the X1 flare and continues in progress. The maximum flux observed so far was 23 PFU at 21/1025 UTC. A greater than 10 MeV proton event began at 21/0225 UTC and also continues in progress. The maximum flux at greater than 10 MeV was 2210 PFU at 21/1315 UTC.

The geomagnetic field is expected to be quiet to unsettled for most of tomorrow. However, an increase is expected late on the 22nd due to a glancing blow from today's partial halo CME. Conditions are expected to attain mostly active with some minor storm periods at high latitudes. There is a slight chance, however, for minor to major storm intervals if the CME should prove to be extraordinarily wide. Conditions should return to unsettled to active by the 24th. The greater than 10 MeV proton event should continue for at least 48 hours and the greater than 100 MeV proton event is expected to continue for the next 12-24 hours.

  Osservato       21 Apr 173
  Previsto   22 Apr-24 Apr  170/175/180
  Media di 90 Giorni        21 Apr 200

  Osservato Afr/Ap 20 Apr  030/062
  Stimato     Afr/Ap 21 Apr  007/007
  Previsto    Afr/Ap 22 Apr-24 Apr  015/015-025/030-015/020