Solar activity was at low levels due to a single C1 x-ray event from Region 1330 (N08E31). Regions 1325 (N15E03), 1327 (S21W54) and 1330) indicated some decay in area. The remaining regions were unchanged.

Solar activity is expected to be low with a slight chance for M-class activity all three days (26 - 28 October). Regions 1324 (N12W26) and 1330 (N08E29) are the most likely to produce moderate level activity.

The geomagnetic field ranged from quiet to severe storm levels. The period began with unsettled to minor storm levels. By 25/0000Z, minor to major storm levels, with high latitude severe storm levels, were observed. From 25/0300Z - 0900Z, active to major storm levels predominated followed by quiet to active levels for the remainder of the period. This increase in activity was likely associated with effects following the arrival of CME activity, first observed on 22 October. Following the interplanetary shock observed at the ACE spacecraft on 24/1748Z. ACE registered increases in wind speed, temperature and density. Solar wind velocities increased from a steady 350 km/s to about 525 km/s, and remained at that speed throughout the period. The interplanetary magnetic field (IMF) Bt increased to above 20 nT from about 24/2000Z through 25/1300Z and gradually decreased to about 8 nT by the end of the period. The Bz component of the IMF reached southward values of -20 nT from about 24/2000Z through 25/0000Z. The remainder of the period observed mostly northward Bz.

The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active periods on day one (26 October), due to lingering effects from the CME that impacted Earth on 24 October. Mostly quiet conditions are expected on day two (27 October). By day three (28 October), quiet to unsettled levels are expected due to effects from a recurrent coronal hole high speed stream.

  Havaittu       25 Oct 139
  Ennusteet   26 Oct-28 Oct  140/140/135
  90 vuorokauden keskiarvo        25 Oct 123

  Havaittu Afr/Ap 24 Oct  016/023
  Arvioitu     Afr/Ap 25 Oct  028/040
  Ennusteet    Afr/Ap 26 Oct-28 Oct  007/012-005/005-007/007