Solar activity reached high levels again this period. Region 139 (N12E32) produced a major flare late in the period, an M5/1n flare (in progress at issue time), and a Type II radio sweep (404 km/s). The flare began at 05/2042Z and appears to have peaked at M5.9 at 2100Z. This region also produced an M2/Sf at 04/2243Z with associated Type II sweep (418 km/s). The rapid growth observed yesterday has slowed considerably, and though no delta configuration is obvious today, the region continues to grow slowly and now nears 700 millionths of white light areal coverage. Region 137 (S19W33) produced an M1/Sf at 05/1046Z. This region has settled down after producing four M-class flares in the last period. Some slight decay was noted. New Regions 141 (S07E20) and 142 (N07E64) were numbered today.

Solar activity is expected to continue at moderate to high levels. M-class activity is likely from Regions 137 and 139, and there's a small chance for another major flare from Region 139.

The geomagnetic field was at unsettled to minor storm levels. The Bz component of the interplanetary magnetic field continues to be predominantly southward. The greater than 2 MeV electron flux reached moderate to high levels.

The geomagnetic field is expected to continue at unsettled to minor storm levels. Transient effects from the rather weak CMEs on 3 and 4 Oct may enhance the disturbed periods on days one and two. A large, recurrent southern coronal hole will move into geoeffective position late on day two through day three.

  Observé       05 Oct 155
  Prévisionnel   06 Oct-08 Oct  160/170/175
  Moyenne des 90 derniers jours        05 Oct 179

  Observé Afr/Ap 04 Oct  043/048
  Estimé     Afr/Ap 05 Oct  022/025
  Prévisionnel    Afr/Ap 06 Oct-08 Oct  020/020-020/020-025/025