Solar activity was very low. No flares occurred during the past 24 hours. New Region 1062 (S18W05) was numbered today as a small sunspot group but was beginning to decay at the end of the period.

Solar activity is expected to be very low for the next three days (13-15 April).

The geomagnetic field ranged from quiet to severe storm levels during the past 24 hours. Activity levels began the interval at unsettled to active levels, but a strong substorm occurred between 0000-0300Z with major to severe storm levels at many of the observatories. Active to minor storm levels prevailed for 0300-0900Z and quiet to unsettled levels for the remainder of the interval from 0900-2100Z. Solar wind observations from the ACE spacecraft showed the continuation of yesterdays disturbed flow associated with the 08 April CME. Of particular note was the northward turning of the Bz component at 0142Z which was preceded by about 13 hours of moderately southward Bz (-5 to -10 nT), evidently triggering the substorm which started shortly after 0200Z. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the past 24 hours.

The geomagnetic field is expected to be quiet with periods of unsettled levels for the first day (13 April). Quiet levels are expected to prevail for the second and third days (14-15 April).

  Observé       12 Apr 075
  Prévisionnel   13 Apr-15 Apr  075/075/075
  Moyenne des 90 derniers jours        12 Apr 083

  Observé Afr/Ap 11 Apr  008/008
  Estimé     Afr/Ap 12 Apr  018/022
  Prévisionnel    Afr/Ap 13 Apr-15 Apr  007/007-005/005-005/005