The geomagnetic field was at unsettled to severe storm levels on August 4. The high latitude magnetometer at Andenes recorded unsettled to major storm levels. The above 10 MeV proton flux was at background levels at the end of the day. The total IMF field increased several times during the day according to ACE data, most likely because of the arrival of CMEs. The first time was gradual after 04:48 UT, while sudden increases were noted at 12:39 and 21:24 UT. The last of these was recorded as a likely solar wind shock at SOHO at 21:29 UT.
Solar flux density measured at 20h UT on 2.8 GHz was 240.8 - increasing 68.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 165.77. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 165.77 on February 4, 2024). The Potsdam WDC planetary A index was 51 (STAR Ap - based on the mean of three hour interval ap indices: 50.6). Three hour interval K indices: 34547744 (planetary), ******** (Boulder), 46456435 (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 14 active regions using 2K resolution (SN: 371) and in 13 active regions using 1K resolution (SN: 265) SDO/HMI images.
AR 13765 [S08W80] rotated partly out of view
and decayed slowly.
AR 13769 [N22W40] produced several C flares.
AR 13770 [N07W83] decayed slowly and rotated to the northwest limb.
AR 13772 [S24W07] lost the magnetic delta configuration, decayed
slowly and was
mostly quiet.
AR 13774 [S07E15] was mostly quiet and stable.
AR 13775 [N18E08] decayed slowly. A minor M class event is possible.
AR 13776 [N09W02] decayed slowly and quietly.
AR 13777 [S08E32] gained a small magnetic delta
near the main penumbra and could produce minor M class flares.
New AR 13779 [N00E24] emerged on August 3 and was number the next day
by SWPC.
New AR 13780 [S09E74] rotated partly into view on August 3 with SWPC
numbering the spot group the following day. The spot group is huge with the
major penumbrae in the north. An X class flare is possible.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9977 [N03W44] was quiet and stable.
S9984 [S14E18] developed slowly and quietly.
S9986 [S28E42] decayed slowly and quietly.
New region S9994 [N14E79] rotated into view with a few spots. The
spot group appears to have a magnetic delta configuration.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.7 | 00:14 | 13780 | GOES16 | simultaneous flare in AR 13766 | |
| C6.5 | 00:46 | S9994 | GOES16 | simultaneous flare in AR 13766 | |
| M1.5 | 01:59 | S9994 | GOES16 | ||
| M1.1 | 02:12 | S9994 | GOES16 | ||
| C8.6 | 02:20 | 13780 | GOES16 | ||
| C5.0 | 03:00 | S9994 | GOES16 | simultaneous flare in AR 13772 | |
| C4.9 | 03:16 | 13774 | GOES16 | ||
| C5.3 | 03:30 | 13769 | GOES16 | simultaneous flare in AR 13780 | |
| C3.9 | 03:52 | 13780 | GOES16 | ||
| C5.6 | 04:31 | 13775 | GOES16 | simultaneous flare in AR 13766 | |
| C6.1 | 05:31 | 13772 | GOES16 | ||
| C5.7 | 05:55 | S9994 | GOES16 | ||
| C4.1 | 07:23 | GOES16 | |||
| C5.6/1F | 08:08 | 13769 | GOES16 | ||
| C3.9 | 08:20 | 13777 | GOES16 | ||
| C4.3 | 08:28 | 13766 | GOES16 | ||
| C5.7 | 09:07 | 13766 | GOES16 | ||
| M1.2 | 09:44 | S9994 | GOES16 | ||
| M1.1 | 10:01 | 13766 | GOES16 | ||
| M1.4 | 10:08 | S9994 | GOES16 | simultaneous flare in AR 13772 | |
| M1.9 | 10:50 | S9994 | GOES16 | ||
| C7.0 | 12:45 | 13769 | GOES16 | ||
| C7.0 | 12:58 | 13772 | GOES16 | ||
| C7.1 | 13:16 | 13766 | GOES16 | ||
| C8.5 | 13:26 | S24E01 | 13772 | GOES16 | |
| C5.4 | 13:54 | 13766 | GOES16 | ||
| C6.8 | 13:59 | 13780 | GOES16 | ||
| C6.1 | 14:58 | 13765 | GOES16 | ||
| M2.2 | 15:15 | 13780 | GOES16 | ||
| C4.2 | 15:37 | 13772 | GOES16 | ||
| C4.4 | 15:54 | 13780 | GOES16 | ||
| C5.1 | 16:11 | 13772 | GOES16 | simultaneous flare in AR 13780 | |
| C5.3 | 16:16 | 13766 | GOES16 | ||
| C3.6 | 17:47 | 13780 | GOES16 | ||
| C4.7 | 17:59 | 13780 | GOES16 | ||
| C3.8 | 19:47 | S9994 | GOES16 | ||
| C3.9 | 20:12 | 13774 | GOES16 | ||
| C4.7 | 20:23 | 13780 | GOES16 | ||
| C4.1 | 21:17 | 13772 | GOES16 | ||
| C4.6 | 21:54 | 13780 | GOES16 | ||
| M1.0 | 22:11 | 13780 | GOES16 | ||
| C4.3 | 22:28 | S9994 | GOES16 | ||
| C4.4 | 23:17 | 13780 | GOES16 | ||
| C6.2 | 23:49 | 13765 | GOES16 | ||
| C5.8 | 23:57 | 13780 | GOES16 |
August 2-4: No obviously Earth directed CMEs were observed.
[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 northern hemisphere positive polarity coronal hole (CH1234) will likely rotate across the central meridian on August 6.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be at quiet to minor storm levels on August 5 due to CME effects. Quiet levels are likely on August 6-7.
| 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 | ||||||||||
| 13765 | 2024.07.23 2024.07.23 |
1 | 2 | 2 | S13W92 | 0060 | HSX | DAC |
 |
 |
beta-delta location: S08W80 area: 0140 merged with AR 13767 |
| 13767 | 2024.07.25 | 1 | S09W78 | 0080 | HSX |
merged into AR 13765 |
|||||
| 13769 | 2024.07.25 2024.07.26 |
3 | 2 | 1 | N23W42 | 0110 | HSX | HSX |
 |
 |
location: N22W40 area: 0170 |
| 13770 | 2024.07.27 2024.07.28 |
2 | 2 | 1 | N08W86 | 0130 | CSO | CSO |
 |
 |
location: N07W83 area: 0230 |
| S9966 | 2024.07.28 | N30W58 | |||||||||
| 13772 | 2024.07.29 2024.07.30 |
21 | 38 | 18 | S25W07 | 0420 | EKC | EKC |
 |
 |
beta-gamma area: 0570 location: S24W07 |
| S9968 | 2024.07.29 | N34W48 | |||||||||
| S9969 | 2024.07.29 | N08W34 | |||||||||
| 13775 | 2024.07.30 2024.07.31 |
10 | 27 | 14 | N18E05 | 0120 | DAI | DAC |
 |
 |
beta-delta location: N18E08 |
| 13774 | 2024.07.30 | 31 | 57 | 33 | S10E14 | 0370 | EKC | EHI |
 |
 |
beta-gamma location: S07E15 area: 0550 |
| S9977 | 2024.07.30 | 3 | 1 | N03W44 | 0007 | BXO |
 |
 |
|||
| 13776 | 2024.07.31 2024.08.01 |
5 | N09W07 | 0010 | BXO |
 |
 |
location: N08W02 |
|||
| 13778 | 2024.07.31 2024.08.02 |
S18W75 |
 |
||||||||
| 13777 | 2024.08.01 2024.08.02 |
2 | 31 | 19 | S10E35 | 0070 | CAO | EAO |
 |
 |
location: S08E32 area: 0220 |
| S9983 | 2024.08.01 | S19W28 | |||||||||
| S9984 | 2024.08.02 | 17 | 13 | S14E18 | 0150 | DAO |
 |
 |
apparently SWPC groups this with AR 13774 | ||
| S9985 | 2024.08.02 | N22E18 | |||||||||
| S9986 | 2024.08.03 | 2 | 1 | S28E42 | 0004 | AXX |
 |
 |
|||
| S9987 | 2024.08.03 | N04W11 |
 |
||||||||
| S9989 | 2024.08.03 | S12E67 |
 |
part of AR 13780 | |||||||
| 13780 | 2024.08.03 2024.08.04 |
7 | 39 | 28 | S10E71 | 0190 | DAI | FKC |
 |
 |
beta-gamma location: S09E74 area: 1600 |
| 13779 | 2024.08.03 2024.08.04 |
4 | 2 | 1 | S01E24 | 0070 | DAO | BXO |
 |
 |
location: N00E24 area: 0006 |
| S9992 | 2024.08.03 | N18E59 |
 |
||||||||
| S9994 | 2024.08.04 | 4 | 3 | N14E79 | 0220 | DAC |
 |
beta-delta | |||
| Total spot count: | 82 | 231 | 135 | ||||||||
| Sunspot number: | 182 | 371 | 265 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 142 | 296 | 200 | (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): | 200 | 204 | 212 | ||||||||
| 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 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.2 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.7 (+5.5) | 10.99 |
| 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 | (134.7 projected, +3.6) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 103.7 | (138.1 projected, +3.4) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (141.7 projected, +3.6) | 9.69 |
| 2024.05 | 187.7 (cycle peak) |
191.9 | 171.7 | (146.2 projected, +4.5) | 23.56 (SC25 peak) |
| 2024.06 | 184.3 | 190.2 | 164.2 | (149.9 projected, +3.7) | 10.24 |
| 2024.07 | 196.9 | 203.0 | 196.5 (SC25 peak) | (151.4 projected, +1.5) | 7.1 |
| 2024.08 | 241.7 (1) | 28.7 (2A) / 222.8 (2B) / 228.0 (2C) | (151.3 projected, -0.1) | (21.2) | |
| 2024.09 | (151.2 projected, -0.1) | ||||
| 2024.10 | (151.1 projected, -0.1) | ||||
| 2024.11 | (149.1 projected, -2.0) | ||||
| 2024.12 | (144.8 projected, -4.3) | ||||
| 2025.01 | (138.6 projected, -6.2) | ||||
| 2025.02 | (133.7 projected, -4.9) | ||||
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 counts in July 2024 were the highest we've seen during solar cycle 25. With three consecutive months of high sunspot counts the projected peak for the smoothed ISN (365 days smoothing) has increased significantly to near 150. The month of the peak is currently likely to occur sometime between June and October 2024.
--------------------------------------------------------------------------------------
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.
