Solar activity was very low. Todays activity consisted of a few low-level B-class events, primarily from newly emerging Region 1061 (N14W11). Region 1061 is a small D-type sunspot group. Region 1060 (N25E45) was quiet and stable and is a small C-type sunspot group.

Solar activity is expected to be very low for the next three days (06-08 April). There is, however a chance for an isolated C-class event from Region 1061.

The geomagnetic field ranged from quiet to severe storm levels during the past 24 hours. Conditions were initially quiet to unsettled, but increased to active levels after 0300Z, and increased further to major to severe storm levels between 0900-1200Z. The increase in activity followed a strong shock observed at the ACE spacecraft at 0756Z which led to a sudden impulse at Earth at 0826Z (observed to be 38 nT at the Boulder magnetometer). Numerous high-latitude stations reported severe storm levels during the interval as did several mid-latitude stations in the nighttime sectors. Activity declined to active to major storm levels from 1200-1800Z and declined further to mostly unsettled levels from 1800-2100Z. Solar wind observations showed elevated solar wind velocity behind the shock with speeds between 720-800 km/s with fairly strong Bz (peak negative values around -15 nT). Solar wind speed and magnetic field observations showed a decreasing trend during the last 4-5 hours of the interval. The most probable source for the disturbance is the halo CME that was observed on 03 April at 0954Z. The greater than 2 MeV electron flux reached high levels during the past 24 hours.

The geomagnetic field is expected to be unsettled to active during the early part of the first day (06 April) due to persistent effects from the current disturbance. In addition, another increase to unsettled levels with a chance for active periods is expected late in the day and continuing through the second day (07 April) due to the onset of a high speed stream from a favorably positioned coronal hole. Activity levels are expected to decline to mostly unsettled levels on the third day (08 April).

  Observé       05 Apr 079
  Prévisionnel   06 Apr-08 Apr  082/085/085
  Moyenne des 90 derniers jours        05 Apr 083

  Observé Afr/Ap 04 Apr  011/013
  Estimé     Afr/Ap 05 Apr  025/025
  Prévisionnel    Afr/Ap 06 Apr-08 Apr  015/017-012/012-008/008