The geomagnetic field was at quiet to minor storm levels on July 30 due to effects from the July 27 CME. 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.
Solar flux density measured at 17h UT on 2.8 GHz was 222.1 - increasing 53.7 over the previous solar rotation. The measurement at 20h UT was heavily flare enhanced and was discarded. (Centered 1 year average SF at 1 AU - 183 days ago: 164.80. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 164.80 on January 30, 2024). The Potsdam WDC planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.4). Three hour interval K indices: 45443312 (planetary), ******** (Boulder), 56545443 (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 17 active regions using 2K resolution (SN: 483) and in 16 active regions using 1K resolution (SN: 323) SDO/HMI images.
AR 13763 [N04W35] was quiet and stable.
AR 13764 [S03W30] was quiet and stable. The separation between this
AR and AR 13766 is becoming hard to observe.
AR 13765 [S11W19] displayed signs of decay. However, the large
trailing penumbra is merging with the leading penumbra of AR 13767.
AR 13766 [S07W27] gained spots and lost area. There is still a chance
of a major flare.
AR 13767 [S09W12] has polarity intermixing and appears to be merging
with AR 13765.
AR 13768 [S16W56] developed and could produce a major flare.
AR 13769 [N22E24] was quiet and stable.
AR 13770 [N08W15] has a magnetic delta configuration in a northern
penumbra. M class flaring is likely.
New AR 13772 [S25E59] rotated into view on July 29 and was numbered
the next day by SWPC. The region has multiple magnetic delta configurations
and produced a major M9 flare peaking before 20h UT.
New AR 13773 [S07W43] emerged with several spots and already has
magnetic delta configurations. An M class flare is possible.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9925 [S12W77] decayed quickly, lost the magnetic delta configuration
and was mostly quiet after noon.
S9966 [N30E07] was quiet and stable.
S9969 [N08E18] developed slowly and quietly.
New region S9974 [N17E73] rotated into view and developed slowly.
New region S9976 [S07E79] rotated into view with large spots and has
major flare potential. The region was the source of an M4.8 flare at 05:23
UT on July 31.
New region S9977 [N04E22] emerged with tiny spots.
New region S9978 [N31W08] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.5 | 00:22 | southeast limb | S9976 | GOES16 | |
| M1.7 | 01:03 | S9925 | GOES16 | ||
| M1.2 | 01:25 | 13765 | GOES16 | incorrectly attributed to AR 13762 by SWPC | |
| M1.3 | 01:32 | 13768 | GOES16 | incorrectly attributed to AR 13762 by SWPC | |
| M1.4 | 01:40 | 13766 | GOES16 | simultaneous flare in AR 13772 | |
| C5.4 | 02:09 | 13766 | GOES16 | ||
| C5.2 | 03:52 | 13772 | GOES16 | ||
| C5.3 | 04:06 | 13768 | GOES16 | ||
| C5.5 | 04:57 | 13769 | GOES16 | ||
| C5.1 | 05:00 | 13765 | GOES16 | ||
| C4.3 | 05:15 | S9925 | GOES16 | ||
| C3.5 | 06:12 | 13766 | GOES16 | ||
| M1.5 | 06:29 | 13766 | GOES16 | simultaneous flare in AR S9925 | |
| C9.0 | 07:17 | 13766 | GOES16 | ||
| C5.8 | 07:55 | 13768 | GOES16 | ||
| C3.9 | 08:18 | S9976 | GOES16 | ||
| C3.5 | 09:07 | 13772 | GOES16 | ||
| C3.3 | 09:31 | 13766 | GOES16 | ||
| C3.7 | 10:05 | 13768 | GOES16 | ||
| C5.6 | 10:37 | 13768 | GOES16 | simultaneous flare in AR S9925 | |
| C5.8 | 11:23 | 13766 | GOES16 | simultaneous flare in AR 13768 | |
| C4.0 | 12:00 | 13772 | GOES16 | ||
| C5.7 | 12:29 | 13768 | GOES16 | ||
| C6.1 | 12:33 | 13770 | GOES16 | ||
| C5.9 | 12:47 | 13766 | GOES16 | ||
| C6.1 | 13:04 | S9925 | GOES16 | ||
| C7.2 | 13:11 | S9925 | GOES16 | ||
| C5.9 | 14:25 | 13770 | GOES16 | simultaneous flare in AR 13768 | |
| C8.4 | 14:51 | 13768 | GOES16 | ||
| C9.5 | 14:55 | S9925 | GOES16 | ||
| C7.9 | 15:32 | S08W26 | 13766 | GOES16 | simultaneous flare in AR S9925 |
| M1.0 | 16:20 | S9925 | GOES16 | ||
| M1.5/1F | 16:28 | S08W27 | 13766 | GOES16 | |
| C7.4 | 17:10 | 13766 | GOES16 | ||
| C4.1 | 17:54 | S9925 | GOES18 | ||
| M1.9 | 19:20 | S04W29 | 13764 | GOES16 | simultaneous flare in AR S9925 at location S11W77 |
| M9.4/2N | 19:37 | S24E64 | 13772 | GOES16 | |
| M3.1 | 20:19 | S27E61 | 13772 | GOES16 | |
| M1.3 | 21:02 | 13773 | GOES16 | ||
| C9.7 | 21:43 | S07W42 | 13773 | GOES16 | |
| C4.4 | 22:14 | 13766 | GOES16 | ||
| C7.5 | 23:08 | 13766 | GOES16 | ||
| C6.3 | 23:34 | 13770 | GOES16 |
July 30: No obviously Earth directed CMEs were observed. A
partial halo CME was observed after the M9 flare in AR 13772, however, no
geomagnetic disturbance is expected at this time.
July 29: A partial halo CME was observed after an M8.7 flare in AR
S9925
peaking at 12:55 UT. There is a chance components of this CME could reach
Earth on August 1.
July 28: A full halo CME was observed after an M9.9 flare in AR 13766
peaking at 01:57 UT. This CME could reach Earth on July 31 and
cause unsettled to minor storm conditions. Multiple other CMEs were
observed during the day, however, it is uncertain if any of those are Earth
directed.
[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 trans equatorial coronal hole (CH1233) rotated across the central meridian on July 30-31, however, CH1233 was in decay most of July 30 and no significant disturbance is expected.
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 quiet to major storm on July 31 - August 1 due to CME effects. Effects from CH1233 could reach Earth on August 2-3 and cause quiet to active 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 | ||||||||||
| S9925 | 2024.07.19 | 14 | 4 | S12W77 | 0250 | CAO |
 |
 |
beta-gamma (including former leading spot section of AR 13762) |
||
| 13762 | 2024.07.19 | 8 | S11W73 | 0180 | EAC |
location: S13W62 SWPC includes AR S9925 in this AR |
|||||
| 13763 | 2024.07.21 2024.07.22 |
2 | 10 | 4 | N02W34 | 0070 | HSX | CSO |
 |
 |
location: N04W35 area: 0210 |
| S9936 | 2024.07.21 | N22W39 | |||||||||
| S9937 | 2024.07.21 | N28W59 | |||||||||
| 13764 | 2024.07.22 2024.07.22 |
4 | 3 | 2 | S03W33 | 0080 | DSO | CAO |
 |
 |
area: 0200 |
| 13765 | 2024.07.23 2024.07.23 |
29 | 36 | 20 | S11W21 | 0480 | DKC | DKC |
 |
 |
area: 0620 location: S11W19 |
| S9948 | 2024.07.23 | N36W41 | |||||||||
| S9951 | 2024.07.23 | N13W58 | |||||||||
| S9953 | 2024.07.23 | S19W38 |
 |
||||||||
| 13766 | 2024.07.24 | 26 | 67 | 32 | S07W25 | 0230 | EAI | EAC |
 |
 |
beta-gamma location: S07W27 area: 0410 |
| 13767 | 2024.07.25 | 15 | 33 | 18 | S09W10 | 0120 | CAO | DAI |
 |
 |
beta-gamma area: 0170 location: S09W12 |
| 13768 | 2024.07.25 2024.07.26 |
20 | 36 | 23 | S16W57 | 0200 | EAC | FKC |
 |
 |
beta-gamma-delta location: S16W56 area: 0660 |
| 13771 | 2024.07.25 2024.07.29 |
5 | N01W58 | 0010 | AXX |
 |
location: N00W56 spotless, unclear what SWPC observed |
||||
| S9959 | 2024.07.25 | S05W41 | |||||||||
| S9960 | 2024.07.25 | N22W48 | |||||||||
| 13769 | 2024.07.25 2024.07.26 |
3 | 12 | 3 | N22E22 | 0080 | HSX | CSO |
 |
 |
location: N22E24 area: 0210 |
| 13770 | 2024.07.27 2024.07.28 |
12 | 30 | 16 | N07W19 | 0260 | DHO | DHC |
 |
 |
beta-delta location: N08W15 area: 0540 |
| S9966 | 2024.07.28 | 3 | 1 | N30E07 | 0004 | BXO |
 |
 |
|||
| 13772 | 2024.07.29 2024.07.30 |
9 | 29 | 19 | S25E59 | 0170 | DAI | EAC |
 |
 |
beta-gamma-delta area: 0360 |
| S9968 | 2024.07.29 | N34E17 |
 |
||||||||
| S9969 | 2024.07.29 | 8 | 4 | N08E18 | 0020 | BXO |
 |
 |
|||
| S9970 | 2024.07.29 | N11W02 |
 |
||||||||
| S9971 | 2024.07.29 | N25W23 |
 |
||||||||
| S9972 | 2024.07.29 | N24E03 |
 |
||||||||
| S9973 | 2024.07.29 | S12E02 |
 |
||||||||
| S9974 | 2024.07.30 | 5 | 4 | N17E73 | 0020 | DRO |
 |
||||
| 13773 | 2024.07.30 2024.07.30 |
8 | 15 | 9 | S06W43 | 0030 | CRI | DRI |
 |
beta-gamma-delta was AR S9975 area: 0060 |
|
| S9976 | 2024.07.30 | 5 | 3 | S07E79 | 0620 | EKO |
 |
||||
| S9977 | 2024.07.30 | 6 | 1 | N04E22 | 0008 | BXO |
 |
||||
| S9978 | 2024.07.30 | 1 | N31W08 | 0002 | AXX |
 |
|||||
| Total spot count: | 141 | 313 | 163 | ||||||||
| Sunspot number: | 261 | 483 | 323 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 204 | 394 | 234 | (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): | 287 | 266 | 258 | ||||||||
| 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 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.9 (+2.4) | 11.16 |
| 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 | (130.8 projected, +1.4) | 5.46 |
| 2024.02 | 172.5 | 168.3 | 123.0 | (134.1 projected, +3.3) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 103.7 | (137.6 projected, +3.5) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (141.2 projected, +3.6) | 9.69 |
| 2024.05 | 187.7 (cycle peak) |
191.9 | 171.7 (SC25 peak) | (145.6 projected, +4.4) | 23.56 (SC25 peak) |
| 2024.06 | 184.3 | 190.2 | 164.2 | (149.3 projected, +3.7) | 10.24 |
| 2024.07 | 195.6 (1) | 180.1 (2A) / 186.1 (2B) / 218.3 (2C) | (150.9 projected, +1.6) | (6.8) | |
| 2024.08 | (150.8 projected, -0.1) | ||||
| 2024.09 | (150.6 projected, -0.2) | ||||
| 2024.10 | (150.6 projected, -0.0) | ||||
| 2024.11 | (148.5 projected, -2.1) | ||||
| 2024.12 | (144.2 projected, -4.3) | ||||
| 2025.01 | (138.4 projected, -6.2) | ||||
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 counts in June 2024 were almost at the level of May 2024 and the second highest month during solar cycle 25. Looking at the projected activity for the remainder of this year, solar max now looks likely to occur between May and October 2024. A big decrease in sunspot formation in July 2024 and over the next months could change the projected maximum to earlier in 2024 or even to December 2023.
--------------------------------------------------------------------------------------
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.
