The geomagnetic field was at unsettled to major storm levels on October 7 due to CME effects. Solar wind speed at SOHO ranged between 440 and 594 km/sec. The high latitude magnetometer at Andenes recorded unsettled to severe storm levels. The above 10 MeV proton flux was at 0.7 pfu at the end of the day, slowly increasing after the X1 LDE in AR 13844.
Solar flux density measured at 17h UT on 2.8 GHz was 243.5 - increasing 38.3 over the previous solar rotation (The measurement at 20h UT was flare enhanced). (Centered 1 year average SF at 1 AU - 183 days ago: 178.72. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 178.72 on April 8, 2024). The Potsdam WDC planetary A index was 53 (STAR Ap - based on the mean of three hour interval ap indices: 53.5). Three hour interval K indices: 65356565 (planetary), 53255454 (Boulder), 65344674 (Andenes).
The background x-ray flux is at the class C3 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 15 active regions using 2K resolution (SN: 365) and in 14 active regions using 1K resolution (SN: 253) SDO/HMI images.
AR 13839 [S14W76] decayed slowly and quietly.
AR 13841 [N11W72] decayed further and could become spotless before
rotating out of view.
AR 13842 [S17W64] continued to lose area and spots. The magnetic
delta within the largest penumbra became even more significant as the
positive polarity umbra is nearly sandwiched between negative polarity
umbrae. The X2 flare did not seem to be associated with a CME, however, the
event seemed to trigger more significant activity in AR 13844.
AR 13844 [S17W80] rotated partly out of view. The X2 flare in AR
13842 apparently triggered first an M7.6 flare peaking at 20:17 and then an
X1.0 long duration event peaking at 20:59 UT. An impressive full halo CME
was observed beginning after the M7 flare.
AR 13847 [S30W04] was quiet and stable.
AR 13848 [N12E03] decayed slowly losing the magnetic delta
configuration while producing a few C flares.
AR 13849 [S08E28] developed slowly and was mostly quiet. Due to the
proximity of AR 13850 there is a chance of the two ARs interacting and
producing a major flare.
AR 13850 [S10E23] developed slowly.
New AR 13851 [S11W10] emerged on October 3 and was numbered by SWPC 4
days later as the spot group decayed slowly.
New AR 13852 [S11E68] rotated into view on October 6 and received its
NOAA number the next day. The spot group may be capable of producing a minor
M flare.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10190 [S20W35] was quiet and stable.
S10195 [N19W54] was quiet and stable
S10200 [S20E08] was quiet and stable.
S10206 [N16E09] was quiet and stable.
New region S10208 [S09W26] was observed with tiny spots in an old
plage area.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.0 | 00:22 | 13842 | GOES16 | ||
| C4.5 | 00:39 | 13842 | GOES16 | ||
| C4.0 | 01:09 | 13851 | GOES16 | ||
| C4.2 | 01:17 | 13848 | GOES16 | ||
| C3.9 | 01:25 | 13844 | GOES16 | ||
| C3.6 | 02:08 | 13844 | GOES18 | ||
| C3.8 | 03:25 | 13842 | GOES18 | ||
| C4.3 | 03:43 | 13842 | GOES18 | ||
| C5.2 | 04:09 | 13842 | GOES18 | ||
| C5.4 | 04:12 | 13842 | GOES18 | ||
| C5.1 | 04:16 | southwest limb | 13843 | GOES18 | |
| C5.9 | 05:32 | S19W58 | 13842 | GOES16 | |
| C4.3 | 05:59 | 13851 | GOES16 | ||
| C4.8 | 06:10 | 13842 | GOES16 | ||
| C3.6 | 07:58 | 13844 | GOES16 | ||
| C4.6 | 08:52 | 13842 | GOES16 | ||
| C4.6 | 08:57 | 13842 | GOES16 | ||
| C6.8 | 09:18 | 13842 | GOES16 | ||
| C5.9 | 09:42 | 13848 | GOES16 | ||
| C6.6 | 10:28 | N11E12 | 13848 | GOES16 | |
| C6.2 | 10:54 | 13842 | GOES16 | ||
| C5.4 | 12:08 | 13844 | GOES16 | simultaneous flare in AR 13842 | |
| C5.5 | 12:15 | southwest limb | 13843 | GOES16 | |
| C4.6 | 13:54 | 13844 | GOES16 | ||
| C6.6 | 14:29 | southwest limb | 13843 | GOES16 | |
| C7.0 | 14:40 | 13842 | GOES16 | ||
| C5.5 | 16:00 | southwest limb | 13843 | GOES16 | |
| C5.5 | 16:20 | 13844 | GOES16 | ||
| C4.2 | 16:46 | southwest limb | 13843 | GOES16 | |
| C4.5 | 17:36 | southwest limb | 13843 | GOES16 | |
| M1.3 | 18:36 | 13844 | GOES16 | ||
| X2.1/2B | 19:13 | S19W63 | 13842 | GOES16 | |
| M7.6/1F | 20:17 | S19W79 | 13844 | GOES16 | moderate type II and weak type IV radio sweeps, halo CME |
| X1.0 | 20:59 | 13844 | GOES16 | LDE |
October 5-6: No obviously Earth directed CMEs observed.
October 7: A full halo CME was observed after the M7 and X1 LDEs in
AR 13844. While Earth is not in the path of the CME core, there is a chance
of a solar wind shock on October 10.
[Coronal
hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago:
28 days ago
27 days ago
26 days ago]
A small positive polarity trans equatorial coronal hole (CH1245) was in an Earth facing position on October 4.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is very poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be at unsettled to major storm levels on October 8 due to CME effects. Quiet to unsettled conditions are likely on October 9. Effects from the October 7 CME could reach Earth on October 10 and cause unsettled to minor storm conditions.
| Coronal holes (1) | Coronal mass ejections (2) | M and X class flares (3) |
1) Effects from a coronal hole could
reach Earth within the next 5 days. When the high speed stream has arrived
the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96
hours.
3) There is a possibility of either M or X class flares within the
next 48 hours.
Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.
(Click on image for 2K resolution).
4K resolution.
Compare to the previous
day's image. 0.5K image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.
Data for all officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.
| Active region | SWPC date numbered STAR detected |
Spot count | Location at midnight | Area | Classification | SDO / HMI 4K continuum image with magnetic polarity overlays |
Comment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SWPC/ USAF |
Magnetic (SDO) |
SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 13841 | 2024.09.25 2024.09.28 |
4 | 3 | 2 | N14W77 | 0010 | BXO | BXO |
 |
 |
location: N11W72 |
| 13839 | 2024.09.26 2024.09.26 |
1 | 1 | 1 | S13W84 | 0020 | HSX | HAX |
 |
 |
area: 0040 location: S14W76 SWPC position is way off |
| 13842 | 2024.09.27 2024.09.28 |
10 | 33 | 20 | S15W63 | 0730 | EKI | EKC |
 |
 |
beta-gamma-delta location: S17W64 |
| S10176 | 2024.09.28 | N17W38 | |||||||||
| 13844 | 2024.09.29 2024.09.30 |
4 | 1 | 1 | S13W84 | 0300 | DKO | HKX |
 |
 |
location: S17W80 area: 0380 |
| S10180 | 2024.09.29 | N01W59 | |||||||||
| S10182 | 2024.09.30 | S07W50 | |||||||||
| 13847 | 2024.09.30 2024.10.01 |
9 | 2 | S27W24 | 0015 | BXO |
 |
 |
location: S30W04 |
||
| 13848 | 2024.10.01 2024.10.02 |
28 | 42 | 26 | N13E01 | 0770 | DKI | DKC |
 |
 |
beta-gamma area: 1170 location: N12E03 |
| S10186 | 2024.10.01 | N17W41 | |||||||||
| S10190 | 2024.10.02 | 7 | 2 | S20W35 | 0010 | BXO |
 |
 |
|||
| 13849 | 2024.10.03 2024.10.04 |
20 | 50 | 29 | S07E23 | 0250 | DKI | DKC |
 |
 |
beta-gamma location: S08E28 area: 0680 |
| S10192 | 2024.10.03 | S09W57 |
 |
||||||||
| S10193 | 2024.10.03 | S22W16 |
 |
||||||||
| 13851 | 2024.10.03 2024.10.07 |
1 | 4 | 2 | S09W11 | 0010 | AXX | BXO |
 |
 |
location: S11W10 |
| S10195 | 2024.10.04 | 2 | N19W54 | 0003 | AXX |
 |
 |
||||
| S10196 | 2024.10.05 | N13E17 | |||||||||
| S10198 | 2024.10.05 | N13W15 | |||||||||
| S10200 | 2024.10.05 | 9 | 2 | S20E08 | 0015 | BXO |
 |
 |
|||
| 13850 | 2024.10.06 2024.10.06 |
3 | 27 | 15 | S10E20 | 0130 | CAO | DAI |
 |
 |
location: S10E23 area: 0300 |
| S10203 | 2024.10.06 | S42E32 |
 |
reversed polarities | |||||||
| 13852 | 2024.10.06 | 3 | 15 | 9 | S12E67 | 0250 | DHO | EKO |
 |
 |
location: S11E68 area: 0580 |
| S10205 | 2024.10.06 2024.10.07 |
N15W38 |
 |
||||||||
| S10206 | 2024.10.06 | 9 | 1 | N16E09 | 0020 | BXO |
 |
 |
|||
| S10208 | 2024.10.07 | 3 | 1 | S09W26 | 0005 | AXX |
 |
||||
| Total spot count: | 74 | 215 | 113 | ||||||||
| Sunspot number: | 164 | 365 | 253 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 134 | 275 | 173 | (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10) | |||||||
| Relative sunspot number (Wolf number): | 180 | 201 | 202 | ||||||||
| Month | Average solar flux | International sunspot number (WDC-SILSO) |
Smoothed sunspot number (4) | Average
ap (3) |
|
|---|---|---|---|---|---|
| Measured | 1 AU | ||||
| 2014.02 | 170.3 (cycle peak) |
166.3 | 146.1 (SC24 peak) | 110.5 | 10.70 |
| 2014.04 | 143.9 | 144.8 | 112.5 | 116.4 (SC24 solar max) | 7.88 |
| 2017.09 | 91.3 | 92.3 | 43.6 | 18.2 (-1.3) | 18.22 (SC24 peak) |
| 2019.11 | 70.2 | 68.7 | 0.5 | 2.0 (-0.6) (Solar minimum using 365d smoothing: November 17, 2019) |
4.19 |
| 2019.12 | 70.8 | 68.6 | 1.6 | 1.8 (-0.2) (ISN 13 months smoothed solar minimum) |
3.22 |
| 2023.01 | 182.4 | 176.6 | 144.4 | 113.3 (+6.6) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 111.3 | 117.8 (+3.5) | 14.48 |
| 2023.03 | 157.2 | 155.6 | 123.3 | 121.1 (+3.3) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 97.6 | 122.9 (+1.8) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.4 | 124.2 (+1.3) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.3 (+1.1) | 8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | 124.6 (-0.7) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | 124.3 (-0.3) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | 124.0 (-0.3) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | 124.8 (+0.8) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | 127.8 (+3.0) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | 129.4 (+1.6) | 9.60 |
| 2024.01 | 164.6 | 159.3 | 126.0 | 131.1 (+1.7) | 5.46 |
| 2024.02 | 172.5 | 168.3 | 123.0 | 136.8 (+5.7) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 103.7 | 141.3 (+4.5) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (145.3 projected, +4.0) | 9.69 |
| 2024.05 | 187.7 | 191.9 | 171.7 | (151.6 projected, +6.3) | 23.56 (SC25 peak) |
| 2024.06 | 184.3 | 190.2 | 164.2 | (155.5 projected, +3.9) | 10.24 |
| 2024.07 | 196.6 |
203.0 | 196.5 | (158.4 projected, +2.9) | 7.13 |
| 2024.08 | 246.1 (cycle peak) |
252.2 | 215.5 (SC25 peak) | (160.4 projected, +2.0) | 15.96 |
| 2024.09 | 195.7 | 197.8 | 141.4 | (163.1 projected, +2.7) | 15.36 |
| 2024.10 | 272.5 (1) | 42.1 (2A) / 186.3 (2B) / 197.4 (2C) | (165.4 projected, +2.3) | (14.1) | |
| 2024.11 | (163.7 projected, -1.7) | ||||
| 2024.12 | (160.7 projected, -3.0) | ||||
| 2025.01 | (156.3 projected, -4.4) | ||||
| 2025.02 | (149.6 projected, -6.7) | ||||
| 2025.03 | (144.8 projected, -4.8) | ||||
| 2025.04 | (141.6 projected, -3.2) | ||||
1) Running average based on the daily 20:00 UTC observed solar flux value
at 2800 MHz and any corrections applied to that measurement.
2A) Current impact on the monthly sunspot number based on the Boulder
(NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
2B) Boulder SN current month average to date.
2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap
indices. Values in red
are based on the definitive international
GFZ Potsdam WDC ap
indices.
4) Source: WDC-SILSO, Royal Observatory
Of Belgium, Brussels
September 2024 saw a significant decrease in sunspot numbers compared to the previous month, however, activity was still fairly high. The average solar flux for the month ranks as number 3 of all months during SC25. Taking into account that we started seeing high sunspot numbers April 14, 2024, the most likely candidate for solar maximum would be at or just after October 14, 2024. Assuming that the average sunspot number from now until April 14, 2025 becomes 150, we would be looking at a 365 days smoothed sunspot maximum of 164.5 centered on October 14. Should the average sunspot number for that period become 160 we would get a peak near 169.7.
--------------------------------------------------------------------------------------
This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to Universal Time. Comments and suggestions are always welcome.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
