Solar activity was low. Region 1330 (N08E45) produced a C1 x-ray event at 23/2237Z. The region continued to evolve as it rotated more fully on the disk. It grew in both area coverage and spot count and developed a beta-gamma magnetic configuration. The other significant region of interest, Region 1324 (N12W13), was quiet and stable during the period. New Region 1332 (N32E78) rotated onto the disk as an H-type spot.

Solar activity is expected to be low with a slight chance for isolated M-class activity. Regions 1324 (N12W13) and 1330 (N08E45) are the most likely for moderate level activity.

The geomagnetic field was at mostly quiet with a single active period observed between 24/1800 - 2100Z. The ACE spacecraft observed an interplanetary shock passage at 24/1748Z with a subsequent sudden impulse of 13 nT observed at the Boulder magnetometer at 24/1832Z. Observations at ACE revealed increases in temperature, density and wind speed while the Bz component of the interplanetary magnetic field (IMF) decreased southward to -20 nT for a brief period. IMF Bt reached 20 nT. Wind velocities increased from a steady 350 km/s to 525 km/s and remained so through the end of the period. This mostly likely was the arrival of a CME that occurred at 22/0058Z in association with an eruptive filament. The greater than 10 MeV proton event that began at 23/1500Z ended at 23/1605Z. A peak flux of 13 pfu was reached at 23/1535Z. Earlier in the period, another, weaker shock passage was observed in the ACE solar wind data at 23/2320Z. This was most likely the result of a glancing blow from a CME associated with an M1.6 x-ray event observed of the NW limb at 20/0325Z .

The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active periods on day one (25 October), due to lingering effects of the 24 October CME passage. By day two (26 October), the field is expected to mostly quiet with isolated unsettled periods returning to mostly quiet on day three (27 October).

  Observé       24 Oct 145
  Prévisionnel   25 Oct-27 Oct  145/140/140
  Moyenne des 90 derniers jours        24 Oct 123

  Observé Afr/Ap 23 Oct  002/003
  Estimé     Afr/Ap 24 Oct  009/010
  Prévisionnel    Afr/Ap 25 Oct-27 Oct  010/012-007/008-005/007