28th October


Solar activity reached high levels when Region 1875 (N07W71,
Fkc/beta-gamma-delta) produced an X1/2N flare at 28/0203 UTC. A Type II
radio emission (451 km/s) was reported at 28/0200 UTC. This event was
followed by an asymmetric halo CME first visible in SOHO/LASCO C2
imagery at 28/0224 UTC. A coarse fit using only SOHO/LASCO C3 imagery
and a preliminary WSA-Enlil model run suggests arrival of ejecta on 30
October. However, the lack of sufficient STEREO COR2 imagery for the
fit means confidence in this solution is low and analysis is ongoing.

An M5/2B from the same region followed at 28/0441 UTC and was
accompanied by a Type II radio emission (508 km/S) at 28/0437 UTC, a
Type IV emission, and a 170 sfu Tenflare at 28/0438 UTC. A CME was
subsequently observed in SOHO/LASCO C2 imagery at 28/0448 UTC. Analysis
of this event suggests the ejecta was directed well westward and the
geoeffective potential low.

Over the past 24 hours, Regions 1875 and 1877 have decreased in area and
1877 lost its delta magnetic configuration. Region 1882 (S09E41,
Dkc/beta-gamma-delta) was relatively stable, losing a few spots but
retaining its beta-gamma-delta configuration. Region 1884 (S14E60,
Dao/beta-gamma-delta) and the remaining regions were relatively stable.
Emerging flux was observed near S15E22 and was being monitored.

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