The geomagnetic field was at quiet levels on July 29. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. The above 10 MeV proton flux was at background levels at the end of the day. A solar wind shock (the arrival of the July 27 CME)was recorded at SOHO at 23:26 UT with a sudden increase in solar wind speed from 326 to 423 km/sec. A geomagnetic disturbance began early on July 30 resulting in active to minor storm conditions.
Solar flux density measured at 20h UT on 2.8 GHz was 223.1 - increasing 59.5 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 164.67. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 164.67 on January 29, 2024). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.8). Three hour interval K indices: 22121122 (planetary), ******** (Boulder), 33133223 (Andenes).
The background x-ray flux is at the class C4 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 19 active regions using 2K resolution (SN: 423) and in 14 active regions using 1K resolution (SN: 280) SDO/HMI images.
AR 13763 [N04W22] was quiet and stable.
AR 13764 [S03W16] decayed slowly and quietly. AR 13766 is very close
to merging with this AR.
AR 13765 [S11W05] expanded and could merge with AR 13767 today.
AR 13766 [S06W14] has magnetic delta configurations and a chance of
producing another major flare. The region could merge with AR 13764 today.
AR 13767 [S09E00] decayed slowly in the trailing spot section and
could merge into AR 13765.
AR 13768 [S17W42] lost spots and some area, however, there are still
magnetic delta configurations and a major flare is possible.
AR 13769 [N22E37] was quiet and stable.
AR 13770 [N07W03] displayed no significant changes and remains
capable of producing M flares.
New AR 13771 [N00W43] emerged on July 25 and was numbered by SWPC 4
days later as the spot group decayed slowly.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9925 [S12W63] decayed slowly and produced several C and M flares. The spot
group lost several magnetic delta configurations and has only one remaining
delta. Further M class flaring is possible.
S9953 [S19W25] was quiet and stable.
S9966 [N30E19] was quiet and stable.
New region S9967 [S24E76] rotated into view with several spots. An M
class flare is possible.
New region S9968 [N34E30] emerged with a tiny spot.
New region S9969 [N06E31] was observed with tiny spots in an
old plage area.
New region S9970 [N11E11] emerged with tiny spots.
New region S9971 [N25W10] emerged with a tiny spot.
New region S9972 [N24E16] emerged with a tiny spot.
New region S9973 [S12E15] was observed with
tiny spots in an old plage area.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C8.9 | 01:30 | 13768 | GOES16 | simultaneous flare in S9967 (and S9925, see next flare) | |
| C9.2 | 01:39 | S10W48 | S9925 | GOES16 | |
| C6.8 | 02:19 | S09E15 | 13767 | GOES16 | |
| X1.5/2B | 02:37 | S06W05 (SDO/AIA) | 13766 | GOES16 | moderate type II radio sweep |
| C9.4 | 03:44 | N09E09 | 13770 | GOES16 | |
| C4.8 | 04:20 | 13770 | GOES16 | ||
| C3.9 | 04:48 | 13765 | GOES16 | ||
| C4.2 | 05:01 | 13765 | GOES16 | ||
| M1.0 | 05:19 | S14W36 | 13768 | GOES16 | |
| C5.1 | 05:44 | southeast limb | S9967 | GOES16 | simultaneous flare in AR 13768 |
| C4.1 | 06:00 | southeast limb | S9967 | GOES16 | |
| C4.3 | 06:24 | S09E13 | 13767 | GOES16 | |
| C3.7 | 07:56 | S06W05 | 13766 | GOES16 | |
| C3.4 | 09:14 | 13770 | GOES16 | ||
| C3.8 | 11:17 | S9925 | GOES16 | ||
| C4.3 | 11:38 | 13768 | GOES16 | ||
| C7.3 | 12:12 | S08E10 | 13767 | GOES16 | |
| M1.6 | 12:22 | S11W56 | S9925 | GOES16 | |
| M8.7 | 12:55 | S9925 | GOES16 | partial halo CME, moderate type II and weak type IV radio sweeps | |
| C6.2 | 13:47 | S16W43 | 13768 | GOES16 | |
| M4.2/1N | 14:46 | S12W04 | 13765 | GOES16 | |
| M2.1 | 15:16 | southeast limb | S9967 | GOES16 | |
| M1.5 | 15:33 | southeast limb | S9967 | GOES16 | |
| C8.7 | 16:07 | 13768 | GOES16 | ||
| C6.6 | 17:14 | S10E01 | 13765 | GOES16 | |
| C5.8 | 17:25 | 13768 | GOES16 | ||
| C9.3 | 17:45 | S11W01 | 13765 | GOES16 | |
| C9.4 | 19:22 | S14W47 | 13768 | GOES16 | |
| C7.1 | 19:34 | 13766 | GOES16 | simultaneous flare in AR 13770 | |
| M6.4 | 19:57 | 13766 | GOES16 | ||
| C8.9 | 20:52 | S9967 | GOES16 | ||
| M1.1 | 21:00 | behind southeast limb | GOES16 | simultaneous flare in AR 13768 | |
| C4.6 | 21:39 | behind southeast limb | GOES16 | ||
| C3.7 | 22:01 | S9925 | GOES16 | ||
| C9.9 | 22:22 | S11W62 | S9925 | GOES16 | |
| C5.0 | 22:47 | 13765 | GOES16 | ||
| C4.9 | 23:04 | 13767 | GOES16 | ||
| C3.7 | 23:32 | S9925 | GOES16 |
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 will most likely reach Earth on July 30 and
cause unsettled to severe storm conditions. Multiple other CMEs were
observed during the day, however, it is uncertain if any of those are Earth
directed.
July 27: A full halo CME was observed after an M3.1 flare in AR S9925
peaking at 05:46 UT. The CME reached Earth early on July 30.
[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) will likely rotate across the central meridian on July 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 poor. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to major storm on July 30 - 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 | 21 | 16 | S12W63 | 0380 | EAC |
 |
 |
beta-gamma-delta (including former leading spot section of AR 13762) |
||
| 13762 | 2024.07.19 | 16 | S10W59 | 0230 | EAC |
 |
location: S13W49 SWPC includes AR S9925 in this AR |
||||
| S9931 | 2024.07.20 | N19W55 | |||||||||
| 13763 | 2024.07.21 2024.07.22 |
2 | 11 | 5 | N04W20 | 0110 | CSO | CSO |
 |
 |
location: N04W22 area: 0200 |
| S9936 | 2024.07.21 | N22W26 | |||||||||
| S9937 | 2024.07.21 | N28W46 | |||||||||
| 13764 | 2024.07.22 2024.07.22 |
1 | 2 | 2 | S03W16 | 0070 | HSX | HSX |
 |
 |
area: 0180 |
| 13765 | 2024.07.23 2024.07.23 |
19 | 35 | 23 | S11W07 | 0460 | DKC | DKC |
 |
 |
area: 0750 location: S11W05 |
| S9948 | 2024.07.23 | N36W28 |
 |
||||||||
| S9950 | 2024.07.23 | N20W59 | |||||||||
| S9951 | 2024.07.23 | N13W45 | |||||||||
| S9952 | 2024.07.23 | S28W54 | |||||||||
| S9953 | 2024.07.23 | 4 | S19W25 | 0010 | BXO |
 |
 |
||||
| 13766 | 2024.07.24 | 23 | 42 | 33 | S07W11 | 0200 | EAI | EKC |
 |
 |
beta-gamma-delta location: S06W14 area: 0470 |
| 13767 | 2024.07.25 | 15 | 28 | 16 | S09E04 | 0140 | DAI | DAI |
 |
 |
area: 0190 location: S09E00 |
| 13768 | 2024.07.25 2024.07.26 |
18 | 30 | 19 | S16W43 | 0180 | EAI | EKC |
 |
 |
beta-gamma-delta location: S17W42 area: 0580 |
| 13771 | 2024.07.25 2024.07.29 |
1 | 2 | 1 | N02W43 | 0010 | AXX | CRO |
 |
 |
location: N00W43 area: 0015 |
| S9959 | 2024.07.25 | S05W28 | |||||||||
| S9960 | 2024.07.25 | N22W35 |
 |
||||||||
| 13769 | 2024.07.25 2024.07.26 |
1 | 8 | 2 | N20E35 | 0080 | CSO | CSO |
 |
 |
location: N22E37 area: 0210 SWPC classification is impossible with just 1 spot |
| 13770 | 2024.07.27 2024.07.28 |
15 | 25 | 14 | N07W05 | 0240 | DAI | DKC |
 |
 |
beta-delta location: N07W03 area: 0530 |
| S9966 | 2024.07.28 | 2 | 2 | N30E19 | 0006 | AXX |
 |
 |
|||
| S9967 | 2024.07.29 | 8 | 4 | S24E76 | 0130 | DAO |
 |
||||
| S9968 | 2024.07.29 | 1 | 1 | N34E30 | 0005 | AXX |
 |
||||
| S9969 | 2024.07.29 | 5 | N06E31 | 0005 | BXO |
 |
|||||
| S9970 | 2024.07.29 | 3 | N11E11 | 0004 | BXO |
 |
|||||
| S9971 | 2024.07.29 | 1 | N25W10 | 0002 | AXX |
 |
|||||
| S9972 | 2024.07.29 | 1 | N24E16 | 0002 | AXX |
 |
|||||
| S9973 | 2024.07.29 | 4 | 2 | S12E15 | 0008 | AXX |
 |
||||
| Total spot count: | 111 | 233 | 140 | ||||||||
| Sunspot number: | 211 | 423 | 280 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 161 | 306 | 213 | (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): | 232 | 233 | 224 | ||||||||
| 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 | 194.7 (1) | 171.6 (2A) / 183.5 (2B) / 216.8 (2C) | (150.9 projected, +1.6) | (6.3) | |
| 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.
