The geomagnetic field was at quiet to minor storm levels on October 28 due to effects from the October 26 CME. Solar wind speed at SOHO ranged between 408 and 670 km/sec. A solar wind shock was observed at 04:19 UT at SOHO as that Oct.26 CME arrived. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at 227 pfu at the end of the day having peaked at 364 pfu at 13:50 UT.
Solar flux density measured at 20h UT on 2.8 GHz was 255.5 - increasing 10.9 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 182.13. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 182.13 on April 29, 2024). The Potsdam WDC planetary A index was 17 (STAR Ap - based on the mean of three hour interval ap indices: 16.6). Three hour interval K indices: 35423322 (planetary), 24424322 (Boulder), 55425444 (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 24 active regions using 2K resolution (SN: 605) and in 17 active regions using 1K resolution (SN: 334) SDO/HMI images.
AR 13863 [S09W62] decayed slowly and was mostly
quiet.
AR 13866 [S13W36] decayed slowly and quietly.
AR 13868 [S11W19] decayed slowly and quietly.
AR 13869 [S18E05] was mostly quiet. The leader spot of AR 13872 is
approaching the largest trailing spot of AR 13869 and the 2 regions could
merge.
AR 13870 [S19W81] was quiet and rotated partly out of view.
AR 13872 [S18E09] was reinterpreted as the previous trailing large
spot was moved to AR 13873. The region decayed slowly and quietly. The
leader spot could merge with AR 13869 in 1-2 days given the current
development.
AR 13873 [S15E18] decayed slowly in the trailing spot section. The
previous trailing spot of AR 13872 was included in this spot group after an
reinterpretation of the magnetic fields and which regions they most likely
belong to.
AR 13874 [N24W18] developed slowly and produced a few C flares.
AR 13875 [N27W01] decayed further and was quiet.
AR 13876 [S05W05] developed and is a compact spot group with major
flare potential.
AR 13877 [S15E37] was quiet and stable.
AR 13878 [N15E65] has a magnetic delta configuration in the large
trailing penumbra. A major flare is possible.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10261 [N17W42] was quiet and stable.
S10277 [N11W28] was quiet and stable.
S10278 [S24E28] was quiet and stable.
S10279 [N14E04] was quiet and stable.
S10282 [N11W10] was quiet and stable.
S10286 [N07W50] reemerged with tiny spots.
S10290 [S21W20] reemerged with tiny spots.
S10292 [N16E43] was quiet and stable.
New region S10293 [N15E87] rotated partly into
view with a huge spot.
New region S10294 [N49W08] emerged at a high latitude with a
tiny spot.
New region S10295 [N10E25] was observed with tiny spots in an old
plage area.
New region S10296 [S01E35] was observed with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C5.0 | 00:30 | 13876 | GOES16 | ||
| C3.1 | 01:29 | 13873 | GOES16 | ||
| C3.8 | 02:30 | 13878 | GOES16 | ||
| C3.8 | 03:02 | 13878 | GOES16 | ||
| C3.3 | 03:26 | 13874 | GOES16 | ||
| M1.3 | 04:09 | 13878 | GOES16 | ||
| C3.3 | 05:12 | 13863 | GOES16 | ||
| C2.8 | 06:01 | 13878 | GOES16 | ||
| C3.8 | 06:15 | 13869 | GOES16 | ||
| C8.0 | 07:01 | N16E75 | 13878 | GOES16 | |
| C4.3 | 07:34 | behind northeast limb | S10293 | GOES16 | |
| C3.2 | 07:55 | behind northeast limb | S10293 | GOES16 | |
| C3.9 | 08:13 | 13878 | GOES16 | ||
| C7.1 | 09:13 | 13878 | GOES16 | simultaneous flare in AR 13874 | |
| C4.5 | 10:07 | S07E02 | 13876 | GOES16 | |
| C9.1 | 14:25 | 13876 | GOES16 | ||
| M1.2 | 14:44 | 13878 | GOES16 | ||
| C9.4 | 15:08 | N16E69 | 13878 | GOES16 | |
| C9.1 | 15:20 | 13876 | GOES16 | ||
| C9.6 | 15:30 | 13876 | GOES16 | simultaneous flare in AR 13873 | |
| M4.2/1F | 16:28 | N16E67 | 13878 | GOES16 | |
| C7.3 | 18:32 | 13878 | GOES16 | ||
| C4.4 | 21:02 | 13878 | GOES16 | ||
| C5.2 | 21:43 | 13878 | GOES16 | ||
| C7.6 | 22:07 | 13878 | GOES16 | ||
| C7.6 | 22:29 | N15E64 | 13878 | GOES16 | |
| C6.4 | 22:44 | 13876 | GOES16 | ||
| C4.7 | 23:12 | 13878 | GOES16 | ||
| C4.8 | 23:34 | 13878 | GOES16 | ||
| C4.5 | 23:49 | 13878 | GOES16 | ||
| C5.1 | 00:05 | 13876 | GOES16 | flare started at 23:56 |
October 27-28: No obviously Earth directed CMEs were observed.
October 26: A fast and well defined full halo CME was observed after
the closely spaced major flares in AR 13872. The CME reached Earth early on
October 28.
[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 negative polarity southern hemisphere coronal hole (CH1250) was Earth facing on October 24-25. A positive polarity northern hemisphere coronal hole (CH1251) could rotate across the central meridian on October 30-31.
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 quiet to unsettled on October 29 due to weakening CME effects. Mostly quiet levels are likely on October 30 - November 1. Quiet to unsettled levels are possible on November 2-3 due to effects from CH1251.
| 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 | ||||||||||
| 13863 | 2024.10.17 2024.10.19 |
7 | 8 | 3 | S08W63 | 0060 | DSO | CRO |
 |
 |
location: S09W62 area: 0030 |
| 13862 | 2024.10.18 2024.10.19 |
S15W73 | |||||||||
| 13865 | 2024.10.19 2024.10.20 |
S22W44 | location: S22W47 | ||||||||
| 13864 | 2024.10.19 2024.10.20 |
N25W65 | location: N25W56 | ||||||||
| 13866 | 2024.10.20 2024.10.21 |
4 | 8 | 1 | S12W36 | 0010 | BXO | BXO |
 |
 |
|
| S10261 | 2024.10.20 | 2 | N17W42 | 0003 | BXO |
 |
 |
||||
| 13867 | 2024.10.20 2024.10.21 |
S15W66 | location: S21W59 | ||||||||
| 13868 | 2024.10.21 2024.10.21 |
1 | 9 | 4 | S11W22 | 0150 | HSX | CSO |
 |
 |
location: S11W19 area: 0230 |
| S10265 | 2024.10.21 | S25W43 | |||||||||
| S10266 | 2024.10.21 | N09W43 | |||||||||
| 13869 | 2024.10.22 2024.10.23 |
45 | 85 | 39 | S15W00 | 0270 | EKI | EAI |
 |
 |
beta-gamma area: 0350 |
| 13870 | 2024.10.22 2024.10.24 |
2 | 1 | 1 | S18W92 | 0060 | CAO | HRX |
 |
 |
location: S19W81 area: 0020 |
| 13875 | 2024.10.23 2024.10.24 |
7 | 12 | 5 | N27W10 | 0020 | CAO | CRO |
 |
 |
location: N27W01 SWPC location is way off |
| S10272 | 2024.10.23 | N18W18 | |||||||||
| 13872 | 2024.10.23 2024.10.24 |
16 | 19 | 3 | S16E14 | 0390 | EKO | CSO |
 |
 |
area: 0180 SWPC data includes trailing spot of AR 13873 location: S18E09 |
| 13871 | 2024.10.24 | S09W08 | part of AR 13869 | ||||||||
| 13873 | 2024.10.24 2024.10.24 |
15 | 54 | 27 | S12E22 | 0100 | CAI | EKC |
 |
 |
beta-gamma-delta location: S15E18 area: 0640 SWPC data does not include leading spot |
| S10275 | 2024.10.24 | N17W53 | |||||||||
| S10276 | 2024.10.24 | S26W36 |
 |
||||||||
| S10277 | 2024.10.24 | 3 | N11W28 | 0007 | AXX |
 |
 |
||||
| S10278 | 2024.10.24 | 3 | S24E28 | 0004 | BXO |
 |
 |
||||
| S10279 | 2024.10.24 | 20 | 3 | N14E07 | 0030 | BXO |
 |
 |
|||
| 13874 | 2024.10.24 2024.10.25 |
25 | 34 | 22 | N24W20 | 0120 | DAI | DAI |
 |
 |
beta-gamma location: N24W18 area: 0310 |
| S10281 | 2024.10.24 | S21W54 | |||||||||
| S10282 | 2024.10.25 | 2 | 1 | N11W10 | 0003 | AXX |
 |
 |
|||
| 13876 | 2024.10.25 2024.10.25 |
30 | 50 | 35 | S05W06 | 0220 | DAI | DAC |
 |
 |
beta-gamma location: S05W05 area: 0420 |
| S10284 | 2024.10.25 | S15E31 | |||||||||
| 13877 | 2024.10.25 2024.10.27 |
1 | 16 | 5 | S15E38 | 0010 | AXX | CRO |
 |
 |
location: S15E37 |
| S10286 | 2024.10.25 | 3 | 2 | N07W50 | 0005 | BXO |
 |
||||
| S10287 | 2024.10.25 | N15W36 | |||||||||
| S10288 | 2024.10.26 | S01W25 | |||||||||
| 13878 | 2024.10.26 2024.10.27 |
8 | 26 | 11 | N18E61 | 0200 | EAI | EKC |
 |
 |
beta-delta location: N16E65 area: 0500 |
| S10290 | 2024.10.26 | 2 | 1 | S21W20 | 0004 | AXX |
 |
||||
| S10291 | 2024.10.27 | N24W17 |
 |
||||||||
| S10292 | 2024.10.27 | 3 | N16E43 | 0005 | AXX |
 |
 |
||||
| S10293 | 2024.10.28 | 1 | 1 | N15E87 | 0610 | HHX |
 |
||||
| S10294 | 2024.10.28 | 1 | N49W08 | 0001 | AXX |
 |
|||||
| S10295 | 2024.10.28 | 2 | N10E25 | 0004 | AXX |
 |
|||||
| S10296 | 2024.10.28 | 1 | S01E35 | 0002 | AXX |
 |
|||||
| Total spot count: | 161 | 365 | 164 | ||||||||
| Sunspot number: | 281 | 605 | 334 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 221 | 432 | 231 | (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): | 309 | 333 | 267 | ||||||||
| 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 | 216.0 (1) | 139.7 (2A) / 154.6 (2B) / 207.7 (2C) ISN monthly average to date: 162 |
(165.4 projected, +2.3) | (19.8) | |
| 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
Sunspot activity in October 2024 increased over September and looks to be headed for an SSN near 160. The average solar flux for October will become the second highest for a month during SC25. The above plot now displays the peak in 365d smoothed sunspot numbers in mid October. ISN has a peak on October 15, NOAA SN on October 14 while both the 1K and 2K SDO SN peaked on October 16. Assuming that the average sunspot number from October 2024 until April 14, 2025 becomes 150, we would be looking at a 365 days smoothed sunspot maximum of 164.5 centered on October 15. 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.
