The geomagnetic field was quiet to unsettled on July 13. Solar wind speed at SOHO ranged between 283 and 383 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. Very weak solar wind shocks were observed at DSCOVR at 11:09 and 15:50 UT, one of them likely the arrival of the July 10 CME.
Solar flux density measured at 20h UT on 2.8 GHz was 202.9 - increasing 45.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 147.29. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 21111322 (planetary), 21222332 (Boulder), 21112332 (Andenes).
The background x-ray flux is at the class C2 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 15 active regions using 2K resolution (SN: 271) and in 12 active regions using 1K resolution (SN: 184) SDO/HMI images.
Region 13361 [N25W78] decayed and lost mature
penumbra on the trailing spots.
Region 13362 [S08W45] was quiet and stable.
Region 13363 [S22W20] was mostly quiet despite the presence of 3
magnetic delta structures. The main penumbra elongated and lost some
latitudinal extension. A major flare is
possible.
Region 13364 [N24W39] decayed slowly and quietly.
Region 13367 [N09W55] decayed slowly and was mostly quiet.
Region 13368 [S18W83] rotated mostly out of view and was
quiet.
Region 13370 [S15E18] decayed slowly and
quietly.
Region 13371 [S16E35] was quiet and stable.
Region 13372 [N23E53] continued to be unstable producing many C
flares and a single M flare. The trailing spot section appears to have at
least one small magnetic delta structure.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S8756 [S15E11] was quiet and stable.
New region S8761 [N22W00] emerged with tiny spots.
New region S8762 [N08E80] rotated into view with mature spots.
New region S8763 [S07E81] rotated into view with a mature spot.
New region S8764 [N17E27] was observed with tiny spots in an old
plage area.
New region S8765 [S00E49] emerged with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C7.5 | 00:42 | 13372 | GOES16 | ||
| C8.0 | 00:58 | 13372 | GOES16 | ||
| C4.8 | 02:08 | 13372 | GOES16 | ||
| C5.5 | 02:22 | 13372 | GOES16 | ||
| C5.2 | 02:48 | N24E62 | 13372 | GOES16 | |
| C5.0 | 03:36 | 13372 | GOES16 | ||
| C4.3 | 03:58 | northeast limb | S8762 | GOES16 | |
| C3.6 | 04:39 | 13361 | GOES16 | ||
| C7.7/1B | 05:11 | 13372 | GOES16 | ||
| C9.3 | 05:21 | 13372 | GOES16 | ||
| C4.3 | 07:34 | 13372 | GOES16 | ||
| C4.8 | 08:13 | 13372 | GOES16 | ||
| C3.4 | 08:50 | 13368 | GOES16 | ||
| C5.1 | 09:55 | southeast limb | S8763 | GOES16 | incorrectly attributed to AR 13372 by SWPC |
| C4.5 | 10:18 | southeast limb | S8763 | GOES16 | |
| C4.7 | 11:20 | southeast limb | S8763 | GOES16 | attributed to simultaneous flare in AR 13372 by SWPC |
| C3.7 | 12:15 | 13372 | GOES16 | ||
| C9.7/1F | 12:44 | 13372 | GOES16 | ||
| C5.7 | 14:03 | southeast limb | S8763 | GOES16 | |
| C5.9 | 14:46 | 13367 | GOES16 | ||
| C3.9 | 16:06 | 13372 | GOES16 | ||
| C4.7 | 16:52 | 13372 | GOES16 | ||
| C3.4 | 17:31 | 13368 | GOES16 | ||
| C5.6 | 18:52 | 13361 | GOES16 | ||
| M2.1/1N | 19:20 | N24E57 | 13372 | GOES16 | |
| C3.6 | 22:29 | N09W53 | 13367 | GOES16 | |
| C6.9 | 22:48 | N25E58 | 13372 | GOES16 |
July 11: An asymmetrical full halo CME was observed after 19:36 UT
following a large filament eruption near and to the southwest of AR 13363.
The CME could reach Earth on July 14 and cause unsettled to major storm
conditions.
July 12-13: 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 recurrent northern hemisphere coronal hole (CH1159) rotated across the central meridian on July 10. CH1159 lost a large part of its area after July 7 due to the development of AR 13367. A trans equatorial area of weak corona has become CH1160. CH1160 was Earth facing July 11-13.
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 active on July 14-16 due to CME and coronal hole effects, minor storm intervals are possible on July 14-15 if the July 11 CME arrives.
| Coronal holes (1) | Coronal mass ejection (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 | ||||||||||
| 13368 | 2023.07.02 2023.07.09 |
1 | S17W92 | 0002 | AXX |
 |
 |
location: N25W83 | |||
| 13361 | 2023.07.02 2023.07.04 |
5 | 4 | 3 | N25W75 | 0150 | CSO | CSO |
 |
 |
location: N25W78 area: 0230 |
| 13362 | 2023.07.04 2023.07.05 |
1 | 3 | 2 | S08W45 | 0020 | HRX | HRX |
 |
 |
|
| 13363 | 2023.07.05 2023.07.06 |
20 | 38 | 20 | S23W20 | 0800 | DKO | DKC |
 |
 |
beta-gamma-delta location: S22W20 area: 1030 |
| 13364 | 2023.07.05 2023.07.06 |
1 | 2 | 1 | N25W39 | 0000 | AXX | AXX |
 |
 |
area: 0003 |
| 13367 | 2023.07.07 2023.07.08 |
16 | 20 | 13 | N10W56 | 0200 | EAI | EAI |
 |
 |
beta-gamma |
| 13369 | 2023.07.08 2023.07.09 |
S18W79 |
location: S19W75 |
||||||||
| S8746 | 2023.07.08 | S29W42 | |||||||||
| 13370 | 2023.07.09 2023.07.10 |
5 | 8 | 2 | S15E21 | 0020 | CRO | CRO |
 |
 |
location: S15E18 |
| S8748 | 2023.07.09 | N31W33 | |||||||||
| 13371 | 2023.07.10 2023.07.11 |
2 | 9 | 4 | S15E34 | 0030 | HAX | HAX |
 |
 |
area: 0090 location: S16E35 |
| S8752 | 2023.07.10 | N15E07 |
 |
||||||||
| S8753 | 2023.07.10 | S29E27 |
 |
||||||||
| 13372 | 2023.07.11 2023.07.11 |
16 | 19 | 12 | N24E53 | 0650 | EKO | FHC |
 |
 |
beta-delta location: N23E53 area: 1230 |
| S8755 | 2023.07.11 | N51W18 | |||||||||
| S8756 | 2023.07.11 | 2 | S15E11 | 0003 | AXX |
 |
 |
||||
| S8757 | 2023.07.11 | N21W11 | |||||||||
| S8758 | 2023.07.12 | N26E16 |
 |
||||||||
| S8759 | 2023.07.12 | S01W08 |
 |
||||||||
| S8761 | 2023.07.13 | 2 | 1 | N22W00 | 0005 | BXO |
 |
||||
| S8762 | 2023.07.13 | 4 | 3 | N08E80 | 0400 | DKO |
 |
||||
| S8763 | 2023.07.13 | 1 | 1 | S07E81 | 0110 | HAX |
 |
||||
| S8764 | 2023.07.13 | 5 | 2 | N17E27 | 0009 | AXX |
 |
||||
| S8765 | 2023.07.13 | 1 | S00E49 | 0001 | AXX |
 |
|||||
| Total spot count: | 66 | 121 | 64 | ||||||||
| Sunspot number: | 146 | 271 | 184 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 107 | 177 | 120 | (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): | 161 | 149 | 147 | ||||||||
| 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 |
| 2021.12 | 103.0 | 99.8 | 67.5 | 55.9 (+5.1) | 6.40 |
| 2022.01 | 103.8 | 100.5 | 55.3 | 60.1 (+4.2) | 8.92 |
| 2022.02 | 109.1 | 106.5 | 60.9 | 64.7 (+4.6) | 10.46 |
| 2022.03 | 117.0 | 115.8 | 78.6 | 68.7 (+4.0) | 10.20 |
| 2022.04 | 130.8 | 131.7 | 84.0 | 73.0 (+4.3) | 11.79 |
| 2022.05 | 133.8 | 136.8 | 96.5 | 77.4 (+4.4) | 7.48 |
| 2022.06 | 116.1 | 119.8 | 70.3 | 81.1 (+3.7) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | 86.7 (+5.6) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 74.6 | 92.5 (+5.8) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | 96.4 (+3.9) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.7 (+2.3) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.0 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.6 (+5.6) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (113.7 projected, +6.1) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 110.9 | (118.5 projected, +4.8) | 14.48 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 122.6 | (121.6 projected, +3.1) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 96.4 | (127.0 projected, +5.4) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.9 | (132.7 projected, +5.7) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 163.4 | (135.9 projected, +3.2) | 8.9 |
| 2023.07 | 176.1 (1) | 64.6 (2A) / 154.1 (2B) / 172.5 (2C) | (135.4 projected, -0.5) | (6.2) | |
| 2023.08 | (136.4 projected, +1.0) | ||||
| 2023.09 | (139.8 projected, +3.4) | ||||
| 2023.10 | (141.6 projected, +1.8) | ||||
| 2023.11 | (144.2 projected max SC25, +2.6) | ||||
| 2023.12 | (143.4 projected, -0.1) | ||||
| 2024.01 | (140.1 projected, -3.3) | ||||
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
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.
