Solar activity was at very low levels with only a single B3 x-ray event recorded at 05/0214Z from Region 1226 (S21W38). New Region 1233 (S18W29) was numbered as a unipolar spot group. No significant changes were observed with the remaining regions on the disk. During the period, LASCO C3 and STEREO-B COR2 imagery observed three separate CMEs. The first two CMEs were back-sided, and appeared to originate from the vicinity of old Region 1222 (N17, L=160) which rotated off the visible disk on 31 May. CME number one was first observed in STEREO Ahead EUVI 195 imagery at 04/0645Z and later in LASCO C3 imagery at 04/2212Z as a partial-halo CME lifting of the east limb. The plane-of-sky speed was estimated at about 1380 km/s. CME number two was first observed in STEREO Ahead EUVI 195 imagery at 04/2145Z and later in LASCO C3 imagery at 05/0733ZZ as an asymmetric full-halo CME lifting off the east limb. The plane-of-sky speed for this CME was estimated at about 2160 km/s. A third CME originated from an eruptive, 16 degree filament centered near N34E37. The filament was first observed lifting off in SDO/AIA 193 imagery at 05/0341Z, with the partial-halo CME first visible in STEREO Behind COR2 imagery at 05/0733Z. The plane-of-sky speed for the third CME was estimated at 490 km/s.

Solar activity is expected to be low with a slight chance for an M-class event all three days (06 - 08 June).

The geomagnetic field was at quiet to major storm levels. The increase in activity was in response to the arrival of the 02 June CME, coupled with a recurrent coronal hole high speed wind stream. After the ACE spacecraft detected the initial interplanetary shock at 04/1958Z, wind velocities rose steadily for the next four hours and reached a peak during the period of 560 km/s at 05/0020Z. Bt reached a maximum of 28 nT at 05/0053Z while the Bz component of the interplanetary magnetic field (IMF) reached a maximum southward value of -19 nT at 04/2157Z. The Bz component remained strongly southward through about 05/0000Z where it turned strongly northward to about +18 nT through 05/0700Z. Thereafter, and through the balance of the period, the Bz component of the IMF did not vary much beyond +/- 7 nT. Associated with the first two CMEs, observed off the east limb, was a greater than 10 MeV proton enhancement that reached a maximum of 3.9 pfu at 05/0050Z. Proton flux values decayed to below 1 pfu after 05/0205Z and remained below through the remainder of the period. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.

The geomagnetic field is expected to be quiet to unsettled, with isolated high latitude active periods, on day one (06 June) due to lingering effects from the CME and recurrent coronal hole high speed stream. On days two and three (07 - 08 June), mostly quiet conditions are expected as the activity subsides. Other than the brief proton ehnhancement observed early on 05 June, no other effects are expected from the three CMEs observed on 04 and 05 June.

  Pozorováno       05 Jun 103
  Předpovězeno   06 Jun-08 Jun  100/098/096
  90 denní průměr        05 Jun 106

  Pozorováno Afr/Ap 04 Jun  011/015
  Odhadovaný     Afr/Ap 05 Jun  020/020
  Předpovězeno    Afr/Ap 06 Jun-08 Jun  008/010-005/005-005/005