Solar activity was moderate during the past 24 hours. Region 134 (N11E38) showed a marked increase in flare productivity during the past 24 hours, including two M-class events. The first was an M1/Sf at 1312 UTC and the second was an M1/Sf at 1942 UTC. Coronagraph data show a relatively narrow CME off the northeast limb in association with the first M-class event. Insufficient data were available at forecast issue time to make any CME association with the second M-class event. Analysis of the Region 134 shows the development of a small delta configuration along an east-west inversion line, and observations indicate the build up of magnetic shear in this part of the region. The only other flare-producing region on the disk was Region 132 (N19W65), which managed to produce a couple C-class subflares, but appeared to be in a state of decline. New Region 135 (S26E06) emerged on the disk today as a simple D-type sunspot group.

Solar activity is expected to be low to moderate. There is a fair chance for additional M-class events from Region 134, and there is a slight chance that Region 132 may produce an isolated M-class event as well.

The geomagnetic field has been quiet to unsettled during the past 24 hours.

The geomagnetic field is expected to be quiet to unsettled for the next 24-36 hours. An increase to unsettled to slightly active is expected late on the second day and should last through the third day in response to a favorably positioned coronal hole.

  觀測的       27 Sep 152
  預測的   28 Sep-30 Sep  150/145/140
  90天平均值        27 Sep 179

  觀測的 Afr/Ap 26 Sep  003/008
  估算值     Afr/Ap 27 Sep  005/008
  預測的    Afr/Ap 28 Sep-30 Sep  005/008-010/012-015/015