Solar activity was high. Region 1263 (N17W83) produced an X6/2b flare at 09/0805Z, the largest x-ray event so far in Cycle 24. This flare was accompanied by multi-frequency radio emissions, including a Tenflare (710sfu), and Type II (1551 km/s) and IV signatures. A full halo CME was subsequently observed in LASCO C3 imagery at 09/0906Z. Initial plane-of-sky speed was estimated to be about 1000 km/s. Earlier in the period, a CME was observed in LASCO C3 imagery at 0406Z. This event was attributed to an M2/1b flare from Region 1263 at 09/03435Z. While the area of Region 1263 diminished over the last 24 hours, the longitudinal extent expanded, and the region ended the period as an Ehc type spot group with a beta-gamma-delta magnetic configuration.

Solar activity is likely to be low to moderate. A slight chance for an isolated X-class flare, and/or proton event, remains for Day 1 (10 August). Event probabilities are expected to gradually decrease as Region 1263 rotates around the west limb.

The geomagnetic field was quiet to unsettled through the period under the continued influence of a coronal hole high speed stream. Solar wind speed at the ACE spacecraft was approximately 600 km/s for most of the period. The Bz component of the interplanetary magnetic field was predominantly near zero. The greater than 100 MeV protons crossed the 1 pfu event threshold at 09/0825Z, reached a maximum of 2 pfu at 09/0855Z, and ended at 09/1045Z. The greater than 10 MeV protons crossed the 10 pfu event threshold at 09/0845Z, reached a maximum of 26 pfu at 09/1210Z, and ended at 09/1715Z. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.

The geomagnetic field is expected to be predominantly quiet to unsettled for the next three days (10-12 August). Unsettled conditions are expected on Day 1 (10 August) as a weak remnant of the 08 August CME arrives. Currently, a return to mostly quiet conditions is expected on Days 2 and 3 (11-12 August). Analysis of the 09/0906Z CME is presently underway to determine its potential geoeffectiveness.

  Pozorováno       09 Aug 098
  Předpovězeno   10 Aug-12 Aug  095/085/085
  90 denní průměr        09 Aug 096

  Pozorováno Afr/Ap 08 Aug  008/010
  Odhadovaný     Afr/Ap 09 Aug  008/008
  Předpovězeno    Afr/Ap 10 Aug-12 Aug  010/010-007/007-005/005