Solar activity summary (Last 24 hours)

10th September

Solar activity returned to low levels. Region 2157 (S14W05,
Ekc/beta-gamma-delta) produced the majority of the flare activity,
including the largest flare of the period, a C3/1n flare at 09/1226 UTC,
and a C2/Sf flare at 10/0524 UTC. This region maintained its delta
magnetic configuration and continued to exhibit signs of growth, mainly
in its intermediate spots. Region 2158 (N15E07, Dkc/beta-gamma) had
noticeable separation of the penumbral area, separating into two
separate magnetic polarities, thus losing its delta magnetic
configuration. Regions 2157 and 2158 continue to be the areas of
interest as they are still the largest and most magnetically complex
regions on the visible disk.

9th September

Solar activity was at moderate (NOAA Scale R1-minor) levels due to a
long-duration M4/1n flare at 09/0029 UTC from Region 2158 (N15E21,
Dkc/beta-gamma-delta). This flare was originally believed to be from
Region 2157 (S15E13, Ekc/beta-gamma-delta), but after additional imagery
became available, was later determined to be from Region 2158. The M4/1n
flare had associated Type II (999 km/s estimated shock velocity) and
Type IV radio sweeps, as well as a 10cm (370 sfu) radio burst.

The associated asymmetrical, full halo coronal mass ejection (CME),
first observed in Lasco C2 imagery at 09/0006 UTC, appears to be
directed mostly northeastward, with the bulk of the ejecta well east of
the sun/Earth line. It does appear, however, that Earth may see a
glancing blow shortly after this forecast period ends.

Region 2157 and Region 2158 remain the largest and most complex regions
on the visible disk. Region 2157 exhibited minor consolidation in its
leader spots with slight development in its southern most intermediate
spots. Region 2158 had minor spot development just north and slightly
south of the large leader spot, and maintained its enhanced magnetic
complexity. Region 2155 (S21W01, Cao/beta) exhibited minor spot growth
in the smaller leader spots, but was otherwise fairly stable. The other
regions on the visible disk remained relatively unchanged.

8th September

Solar activity was at low levels. Region 2157 (S14E24,
Ekc/beta-gamma-delta) continued to produce mid-range C-class flares.
The largest was a C7 flare at 07/1943 UTC. Region 2157 had slight to
moderate growth over the period within its intermediate spot area and
still retains a SE-NW inversion line within its much larger trailing
spot complex. Region 2158 (N15E35, Dkc/beta-gamma-delta), although
relatively quiet recently, appeared to have slight rotation of its
positive leader with penumbral fluctuations along its delta. No
Earth-directed coronal mass ejections were observed during the period.

7th September

Solar activity was at moderate levels due to an M1/Sf flare at 06/1709
UTC from Region 2157 (S14E37, Ekc/beta-gamma-delta). Region 2157 had
some minor intermediate spot growth over the period and maintains a
SE-NW inversion line through the lower half of its much larger trailing
spot cluster. Region 2158 (N15E47, Dkc/beta-gamma-delta) did not
produce any significant flares, however the most recent imagery SDO/HMI
imagery suggests that separation may be occurring along its delta.
Region 2159 (S21E53, Cro/beta), although a relatively simple beta group,
managed a C7 flare at 07/0204 UTC. Accompanying this flare were Type II
(700 km/s) and Type IV radio sweeps as well as a coronal mass ejection
(CME) first observed in SDO/AIA 193 imagery at 07/0200 UTC off the
eastern limb. Further analysis will be made as LASCO imagery becomes
available, however given its location and the direction of the ejecta,
it is unlikely to be geoeffective. An analysis of the CME associated
with the C8 flare that was observed in LASCO/C2 imagery at 06/1012 UTC
(as mentioned in the 07/0030 UTC Forecast Discussion) was determined to
not be geoeffective.

6th September

Solar activity continued at low levels. The largest flare was a C8/1n
at 06/0814 UTC from Region 2157 (S14E51, Dkc/beta-gamma-delta). Slight
growth was observed in Region 2157 as well as Region 2158 (N15E61,
Dkc/beta-delta). Region 2157 has a well defined delta running in a
SE-NW orientation through the lower half of the spot group. Region 2158
appears to have a reverse polarity delta splitting the compact spot
group almost directly through the center running approximately N-S. No
Earth directed coronal mass ejections (CMEs) were observed during the

5th September

Solar activity remained at low levels. Region 2157 (S13E61,
Dai/beta) produced the largest flare of the period, a C6/1n flare at
05/0616 UTC, as well as several other C-class flares throughout the
period. This region exhibited slight growth as it continued to rotate
onto the visible disk. Region 2152 (S15W45, Eko/beta-gamma) also
produced a C6 flare early in the period, but was fairly inactive the
rest of the day. Region 2152 exhibited some consolidation in its trailer
spots, but remained fairly stable overall. The remaining five spot
groups were either stable or exhibited signs of decay.

A narrow coronal mass ejection (CME) was observed in Lasco C3 imagery
departing the east limb at 05/0806 UTC. This CME is likely associated
with the C6/1n flare from Region 2157. Analysis indicated a velocity of
near 700 km/s, however the trajectory is too far east to have any
impacts on Earth.

4th September

Solar activity reached moderate levels. Region 2155 (S20E65, Hax/alpha)
produced an M2/Sf flare at 03/1354 UTC. Analysis indicated the
associated coronal mass ejection (CME) was moving at 550 km/s, but did
not appear to be Earth-directed. Old Region 2149 (N09, L=283) remained
active as it continues to transit behind the west limb. This region was
responsible for a C5 flare at 03/2124 UTC, as well as a C2 flare at
04/0228 UTC. Initial indications suggest the bulk of the CME is directed
too far west to be a threat.

Region 2152 (S16W31, Eki/beta-gamma) exhibited some consolidation in its
leader spots. Region 2153 displayed consolidation in its trailer spots
and was predominantly inactive through out the period. Regions 2156
(N15E63, Bxo/beta) and 2157 (S13E75, Hax/alpha) were numbered during the

3rd September

Solar activity remained at low levels. The largest flare of the period,
a C4 flare at 03/0253 UTC, appeared to originate from a region just
beyond the southeastern limb. Region 2152 (S15W19, Eac/beta-gamma) also
produced a few low level C-class flares during the period. This region
continued to grow, primarily in its intermediate spot area, and show
signs of separation between the leader and trailer spots. Region 2153
(S10W45, Dao/beta) exhibited signs of decay during the period. Region
2154 (S19E29, Cao/beta) continued to show signs of growth, though that
growth rate slowed near the end of the period.

SDO AIA/304 imagery captured a 44 degree long filament, centered near
N32W14, erupting between 02/1300-1600 UTC. The eruption was also evident
in ground-based H-alpha imagery from the GONG facilities. Initial
analysis indicated there is an Earth-directed component of the coronal
mass ejection (CME), set to arrive early to midday on 6 Sep, just
outside this forecast period. Further analysis will be conducted on this
CME and adjustments to the forecast will be made accordingly.

2nd September

Solar activity was at low levels. Region 2152 (S16W05,
Eac/beta-gamma)produced a C2/Sf flare at 02/0059 UTC, the largest flare
of the period, as well as other low level C-class flares. This region
continued to grow, primarily in its intermediate spot area. Region 2153
(S10W31, Dao/beta) also grew significantly during the period, mainly in
its leader spot area. The remaining spot groups were stable and appeared
to be fairly stable.

A Type II radio sweep (estimated velocity 1,094 km/s) was observed at
01/2211 UTC along with a Type IV sweep associated with an eruption off
the east limb. No flare accompanied the event and the resulting CME
appears to be headed well east of the Sun-Earth line. Two additional
CMEs were observed in Lasco C2 imagery departing the east limb. The
first became visible at 01/2224 UTC, with the second one first showing
at 02/0236 UTC. Both appear to have an eastward trajectory, resulting in
likely non-Earth directed CMEs. There was also a faint, partial halo CME
that became visible in the Lasco C2 imagery at approximately 01/2136
UTC. This CME had a mostly northwesterly trajectory, but will be modeled
as soon as imagery is available.

The other notable feature on the visible disk was a nearly 38 degree
long filament, centered near N19W10, that appeared to be beginning to
lift off from the corona. At the time of this discussion, it had not
erupted nor lifted off, but will be monitored closely.

1st September

Solar activity remained at low levels. Region 2149 (N09W70, Dkc/beta)
was the prominent flare producer this period. Region 2149 produced a C7
flare at 31/1211 UTC which was the largest event of the period. In
addition to numerous low-level C-class flares, Region 2149 produced a
long duration C2/Sf flare at 01/0744 UTC. A Type-II radio emission at
01/1113 UTC with an estimated velocity of 2,079 km/s is believed to be
associated with activity behind the east limb.

Region 2149 continued to exhibit a minor trend of penumbral decay as it
approaches the west limb. Region 2152 (S16E08, Dac/beta-gamma) also
began a trend of decay but maintained a weak beta-gamma magnetic
configuration. Region 2153 (S10W17, Cao/beta) showed signs of
development in its trailer spot area early in the period but, along with
the other regions on the visible disk, was relatively stable throughout
the remainder of the period.

A coronal mass ejection (CME) associated with the long duration C2/Sf
flare from Region 2149 at 01/0744 UTC was observed off the northwest
limb in SOHO/LASCO C2 coronagraph imagery beginning at 01/0924 UTC.
Additional imagery and analysis is needed to determine if this CME has
an Earth-directed component. At the time of this writing, no
Earth-directed CMEs were observed.