Solar activity was low. Region 338 (N18W20) continued to develop in both size and magnetic complexity. It was responsible for most of the C-class activity this period, including a C4/Sf flare at 22/2011Z. There were some indications that a weak delta configuration was developing in this region. A Type II (960 km/s) radio sweep was detected at 22/0716Z, associated with a CME off the NE limb. A CME was also detected earlier in the period, associated with a B-class flare in Region 336 (N14E10). The largest region on the disk - Region 337 (S14E29), exhibited some decay and simplification over the past 24 hours. These CMEs do not appear to be Earthward directed. Minor C-class activity was observed in Regions 337 (S14E29), and 339 (N16W71). New Region 342 (N18W07) was numbered today.

Solar activity is expected to be at low levels. There is a chance for a low level M-class flare from Region 337 or Region 338.

The geomagnetic field was unsettled to active. A high speed solar wind stream that began early on 21 April continues. Solar wind speeds exceeded 600 km/s early in the period, but gradually declined to below 550 km/s by the end of the period. The greater than 2 MeV electrons at geosynchronous orbit reached high levels again today.

The geomagnetic field is expected to be at unsettled to minor storm levels. The most disturbed periods are expected late on day one through day two due to the anticipated arrival of a CME associated with the M2/1n flare on 21/1307Z. A return to predominantly unsettled conditions is expected on day three with occasional active periods possible.

  Observé       22 Apr 132
  Prévisionnel   23 Apr-25 Apr  140/145/145
  Moyenne des 90 derniers jours        22 Apr 126

  Observé Afr/Ap 21 Apr  012/021
  Estimé     Afr/Ap 22 Apr  015/022
  Prévisionnel    Afr/Ap 23 Apr-25 Apr  020/030-020/025-015/015