The geomagnetic field was quiet to active on July 17 due to CME effects (most likely related to the July 14 CME). Solar wind speed at SOHO ranged between 406 and 618 km/sec. The high latitude magnetometer at Andenes recorded quiet to minor storm levels.
Solar flux density measured at 20h UT on 2.8 GHz was 180.0 - decreasing 0.1 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 147.42. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 19.0). Three hour interval K indices: 32443244 (planetary), 32443344 (Boulder), 32354354 (Andenes).
The background x-ray flux was at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 295) and in 11 active regions using 1K resolution (SN: 194) SDO/HMI images.
Region 13363 [S21W72] decayed with the large
penumbra partly splitting in the south. A major long duration M5.7 flare
peaked at 00:06 UT on July 18. A proton event began at 00:20 UT and the
above 10 MeV flux has so far peaked at 609 pfu at 05:00 today. A large and
wide partial halo CME was observed before the flare
peaked, LASCO C2 imagery displays the initial part of the CME at 23:36 UT.
Region 13370 [S14W33] was quiet and stable.
Region 13371 [S15W19] decayed slowly and
quietly.
Region 13372 [N23E02] decayed and has only a small magnetic delta
remaining in the easternmost trailing penumbra. M flares are still possible.
Region 13373 [N08E28] developed further with the magnetic delta
structure in the intermediate spot section enlarging. A major flare is
possible. C1 flares: C1.6 @ 02:48 UT
Region 13374 [S08E28] was quiet and stable.
New region 13375 [N12W52] emerged on July 15 and began to decay when
it was numbered by SWPC 2 days later.
New region 13376 [N24E43] developed many spots and was numbered by
SWPC 2 days after the first spots were observed.
New region 13377 [S09E74] rotated into view with a few spots. C
flares are possible.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S8764 [N16W21] was quiet and stable.
S8767 [N19W46] decayed slowly and quietly.
New region S8775 [S27E73] rotated into view with a small spot.
New region S8776 [S06W15] emerged with a tiny spot.
New region S8777 [S19E28] was observed with a tiny spot in an old
plage region.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.5 | 00:07 | 13363 | GOES16 | ||
| C2.7 | 01:42 | 13377 | GOES16 | ||
| C2.2 | 02:14 | 13363 | GOES16 | ||
| C2.2 | 03:23 | 13377 | GOES16 | ||
| C4.4 | 03:40 | 13377 | GOES16 | incorrectly attributed to AR 13363 by SWPC | |
| C4.1 | 03:53 | 13363 | GOES16 | ||
| C2.8 | 04:34 | N08E43 | 13373 | GOES16 | |
| C2.9 | 04:43 | 13377 | GOES16 | ||
| C3.9 | 05:16 | 13377 | GOES16 | incorrectly attributed to AR 13372 by SWPC | |
| C3.7 | 06:04 | N08E43 | 13373 | GOES16 | |
| C4.3 | 06:55 | N09E38 | 13373 | GOES16 | |
| C3.7 | 08:18 | N08E43 | 13373 | GOES16 | |
| C4.3 | 06:55 | N09E38 | 13373 | GOES16 | |
| C3.7 | 08:18 | 13373 | GOES16 | ||
| C4.2 | 09:26 | S25W70 | 13363 | GOES16 | |
| C2.6 | 10:29 | 13373 | GOES16 | ||
| C2.7 | 11:08 | 13363 | GOES16 | ||
| C3.4 | 11:21 | 13372 | GOES16 | ||
| C3.5 | 11:52 | 13372 | GOES16 | ||
| C2.9 | 12:18 | 13373 | GOES16 | ||
| C3.0 | 12:43 | 13363 | GOES16 | ||
| C2.5 | 13:02 | 13373 | GOES16 | ||
| C3.3 | 14:55 | 13363 | GOES16 | ||
| C6.6 | 15:16 | N27E12 | 13372 | GOES16 | |
| C2.6 | 16:14 | 13363 | GOES16 | ||
| C2.5 | 17:33 | N06E32 | 13373 | GOES16 | |
| C2.4 | 17:41 | 13373 | GOES16 | ||
| C3.2 | 18:29 | 13377 | GOES16 | ||
| C2.9 | 18:54 | 13363 | GOES16 | ||
| C3.3 | 20:01 | N07E30 | 13373 | GOES16 | |
| C5.9 | 22:11 | 13373 | GOES16 | ||
| C7.4 | 22:32 | 13363 | GOES16 | ||
| M2.7 | 22:54 | 13363 | GOES16 | ||
| M5.7 | 00:06 | 13363 | GOES16 | SWPC has 23:37 UT as the start time for the
flare, the leading CME edge was observed one minute earlier Using SDO/AIA imagery the start time was likely near 23:15 UT Proton event. Large partial halo CME |
July 15-16: No obviously Earth directed CMEs were
observed.
July 17-18: An asymmetrical full halo CME was observed after an M5 flare in AR 13363 at
00:06
UT on July 18. Due to the source location near the southwest limb it is
uncertain when the CME will reach Earth, currently the estimate is sometime
between late on July 19 and early on July 21.
[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 southern hemisphere coronal hole (CH1161) will be in an Earth facing position on July 18.
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 due to proton event effects. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to active on July 18 due to CME effects. Quiet to unsettled is likely on July 19. It is uncertain when the July 17/18 CME will reach Earth, unsettled to major storm levels are likely on July 20-21. Effects from CH1161 will probably not be noticeable due to CME effects.
| 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 | ||||||||||
| 13363 | 2023.07.05 2023.07.06 |
10 | 16 | 7 | S22W74 | 0700 | DKO | CKO |
 |
 |
location: S21W72 |
| 13370 | 2023.07.09 2023.07.10 |
2 | S15W34 | 0002 | BXO |
 |
 |
location: S14W33 |
|||
| 13371 | 2023.07.10 2023.07.11 |
1 | 4 | 2 | S15W19 | 0020 | HRX | HRX |
 |
 |
|
| S8752 | 2023.07.10 | N17W40 | |||||||||
| S8753 | 2023.07.10 | S29W23 | |||||||||
| 13372 | 2023.07.11 2023.07.11 |
21 | 36 | 20 | N23E02 | 0700 | FHO | FHO |
 |
 |
beta-delta area: 0950 |
| S8756 | 2023.07.11 | S15W41 | |||||||||
| S8758 | 2023.07.12 | N26W36 | |||||||||
| S8761 | 2023.07.13 | N22W52 | |||||||||
| 13373 | 2023.07.13 2023.07.14 |
20 | 39 | 22 | N07E25 | 0450 | EKC | EKC |
 |
 |
beta-gamma-delta area: 0920 location: N08E28 |
| 13374 | 2023.07.13 2023.07.14 |
1 | 6 | 2 | S16E27 | 0030 | HRX | CAO |
 |
 |
area: 0050 location: S08E28 |
| S8764 | 2023.07.13 | 10 | 3 | N16W21 | 0020 | AXX |
 |
 |
|||
| S8765 | 2023.07.13 | S00W03 | |||||||||
| S8766 | 2023.07.14 | N27W17 | |||||||||
| S8767 | 2023.07.15 | 2 | 1 | N19W46 | 0003 | BXO |
 |
 |
|||
| S8768 | 2023.07.15 | S24W08 | |||||||||
| 13375 | 2023.07.15 2023.07.17 |
4 | 7 | 4 | N12W53 | 0020 | CRO | BXO |
 |
 |
|
| S8771 | 2023.07.15 | S32E34 | |||||||||
| 13376 | 2023.07.15 2023.07.17 |
11 | 25 | 18 | N24E43 | 0030 | DRO | DRI |
 |
 |
|
| S8773 | 2023.07.16 | S28W38 |
 |
||||||||
| 13377 | 2023.07.17 2023.07.17 |
1 | 5 | 4 | S09E71 | 0030 | DSO | DAO |
 |
was AR S8774 location: S09E74 area: 0390 |
|
| S8775 | 2023.07.17 | 1 | 1 | S27E73 | 0020 | HRX |
 |
||||
| S8776 | 2023.07.17 | 1 | S06W15 | 0002 | AXX |
 |
|||||
| S8777 | 2023.07.17 | 1 | S19E28 | 0001 | AXX |
 |
|||||
| Total spot count: | 69 | 155 | 84 | ||||||||
| Sunspot number: | 149 | 295 | 194 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 116 | 204 | 133 | (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): | 165 | 162 | 155 | ||||||||
| 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 | 177.2 (1) | 80.3 (2A) / 146.4 (2B) / 169.9 (2C) | (135.4 projected, -0.5) | (7.9) | |
| 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.
