23rd October


Solar activity was moderate. Region 1875 (N09W05, Ekc/beta-gamma-delta)
continued to be the most active region, producing the vast majority of
the flare activity. It produced the two largest flares of the period, an
M1/Sf flare at 22/1520 UTC and an impulsive M4/1b at 22/2120 UTC. The M4
flare was associated with a 220 sfu Tenflare and a Type II radio sweep
(estimated shock speed 1955 km/s). This region continued to exhibit a
beta-gamma-delta magnetic configuration with separate deltas in its
trailer and intermediate spots. Region 1877 (S13E17,
Dki/beta-gamma-delta) decreased in area from 390 millionths to ~250
millionths, but developed a delta in its intermediate spots. It was also
responsible for a few low-level C-class flares throughout the period.

A faint, asymmetric full halo CME, associated with the M4/1b flare, was
observed in Lasco C2 imagery at ~22/2200 UTC. WSA Enlil analysis
indicates speeds of approximately 668 km/s with at least a portion of
the ejecta expected to impact the Earth early on 26 Oct. The current WSA
Enlil run has all four of the CMEs from the past three days included.

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