The geomagnetic field was quiet on July 19. Solar wind speed at SOHO ranged between 369 and 515 km/sec. The high latitude magnetometer at Andenes recorded quiet levels.
Solar flux density measured at 20h UT on 2.8 GHz was 188.9 - increasing 15.7 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 147.68. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.8). Three hour interval K indices: 11111111 (planetary), 11212312 (Boulder), 02222222 (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 13 active regions using 2K resolution (SN: 301) and in 12 active regions using 1K resolution (SN: 211) SDO/HMI images.
Region 13371 [S15W36] was quiet and stable.
Region 13372 [N22W25] decayed slowly in the trailing spot section and
produced a few C flares.
Region 13373 [N08E02] decayed slowly in the leading ant intermediate
spot sections. Two small magnetic delta structures are still present. A major flare is
still possible.
Region 13374 [S08E02] decayed slowly and quietly.
Region 13376 [N23E16] decayed in the northern spot section and
produced a few C flares.
Region 13377 [S09E47] developed intermediate spots. An M flare is
possible.
New region 13378 [S27E13] emerged on July 18 with SWPC numbering the
group the next day.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S8775 [S27E48] decayed slowly and quietly.
S8779 [N14E71] rotated full into view and has a large leader spot.
This and AR S8780 are AR 13379 to SWPC. C1 flares: C1.9 @ 02:09 UT
S8780 [N19E73] was quiet and stable.
S8781 [N15E28] was quiet and stable.
New region S8782 [N12E33] emerged with reversed polarities.
New region S8783 [S25W02] was observed with tiny spots in an
old plage area.
C1 flares from AR 13363: C1.9 @ 05:25 UT
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.4 | 00:22 | 13363 | GOES16 | ||
| C2.0 | 01:00 | 13363 | GOES16 | ||
| C2.5 | 04:19 | 13363 | GOES16 | ||
| C2.4 | 06:08 | 13363 | GOES16 | ||
| C2.4 | 06:58 | N24W06 | 13372 | GOES16 | |
| C2.9 | 07:16 | 13363 | GOES16 | ||
| C3.1 | 08:24 | 13363 | GOES16 | ||
| C3.4 | 08:37 | 13363 | GOES16 | ||
| C2.1 | 09:02 | 13363 | GOES16 | ||
| C2.4 | 09:35 | 13363 | GOES16 | ||
| C2.3 | 09:57 | 13363 | GOES16 | ||
| C3.6 | 10:29 | 13363 | GOES16 | ||
| M1.4 | 10:57 | S20W90 | 13363 | GOES16 | |
| C3.3 | 11:10 | 13363 | GOES16 | ||
| C2.3 | 12:14 | 13363 | GOES16 | ||
| C2.7 | 13:14 | 13363 | GOES16 | ||
| C2.3 | 14:21 | 13363 | GOES16 | ||
| C3.0 | 13:48 | 13363 | GOES16 | ||
| C2.8 | 15:07 | 13363 | GOES16 | ||
| C2.4 | 15:45 | 13363 | GOES16 | ||
| C2.4 | 16:45 | 13363 | GOES16 | ||
| C2.9 | 16:51 | 13377 | GOES16 | ||
| M3.8 | 17:25 | 13363 | GOES16 | weak type II radio sweep | |
| C3.2 | 19:04 | 13363 | GOES16 | ||
| C2.6 | 21:46 | N24E18 | 13376 | GOES16 | |
| C2.9 | 23:17 | 13376 | GOES16 | ||
| C2.5 | 23:43 | 13376 | GOES16 |
July 19: No obviously Earth directed CMEs were
observed.
July 17-18: An asymmetrical full halo CME was observed beginning
before the peak of a long duration M5 flare in AR 13363 at
00:06
UT on July 18. LASCO C2 observed the CME beginning at 23:36 UT on July 17. Due to the source location near the southwest limb it is
uncertain when the CME will reach Earth, 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) was 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 poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to minor storm on July 20-21 due to CME effects. It is still uncertain when the July 17/18 CME will reach Earth. Effects from CH1161 are possible on April 21-22 should the April 17 CME fail to reach Earth..
| 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 | ||||||||||
| 13370 | 2023.07.09 2023.07.10 |
S15W62 |
 |
||||||||
| 13371 | 2023.07.10 2023.07.11 |
2 | 1 | S15W39 | 0004 | AXX |
 |
 |
location: S15W36 |
||
| S8753 | 2023.07.10 | S29W49 | |||||||||
| 13372 | 2023.07.11 2023.07.11 |
15 | 39 | 22 | N24W24 | 0500 | FHO | FHO |
 |
 |
area: 0700 location: N22W25 |
| 13373 | 2023.07.13 2023.07.14 |
24 | 39 | 24 | N07E01 | 0500 | EKC | EKI |
 |
 |
beta-gamma-delta area: 0920 location: N08E02 |
| 13374 | 2023.07.13 2023.07.14 |
1 | 9 | 2 | S07E01 | 0010 | HRX | CRO |
 |
 |
area: 0020 |
| S8764 | 2023.07.13 | N17W51 |
 |
||||||||
| S8765 | 2023.07.13 | S00W29 | |||||||||
| S8766 | 2023.07.14 | N27W43 | |||||||||
| S8768 | 2023.07.15 | S24W34 | |||||||||
| 13375 | 2023.07.15 2023.07.17 |
1 | N13W80 | 0000 | AXX |
 |
spotless | ||||
| S8771 | 2023.07.15 | S32E08 | |||||||||
| 13376 | 2023.07.15 2023.07.17 |
7 | 26 | 13 | N25E16 | 0150 | DSO | DKO |
 |
 |
area: 0310 location: N23E16 |
| 13377 | 2023.07.17 2023.07.17 |
4 | 10 | 9 | S09E47 | 0240 | DSO | DHI |
 |
 |
area: 0590 |
| S8775 | 2023.07.17 | 4 | 1 | S27E48 | 0010 | AXX |
 |
 |
|||
| S8776 | 2023.07.17 | S06W41 | |||||||||
| S8777 | 2023.07.17 | S19E02 | |||||||||
| 13378 | 2023.07.18 2023.07.19 |
6 | 25 | 10 | S26E13 | 0030 | DRO | DRI |
 |
 |
area: 0090 |
| S8779 | 2023.07.18 | 7 | 5 | N14E71 | 0510 | FHO |
 |
 |
|||
| S8780 | 2023.07.18 | 1 | 1 | N19E71 | 0140 | HSX |
 |
 |
|||
| S8781 | 2023.07.18 | 4 | 1 | N15E28 | 0007 | BXO |
 |
 |
|||
| 13379 | 2023.07.19 | 3 | N16E70 | 0180 | DSO | ARs S8779+S8780 | |||||
| S8782 | 2023.07.19 | 2 | 2 | N12E33 | 0009 | BXO |
 |
reversed polarities | |||
| S8783 | 2023.07.19 | 3 | S25W02 | 0005 | AXX |
 |
|||||
| Total spot count: | 61 | 171 | 91 | ||||||||
| Sunspot number: | 141 | 301 | 211 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 102 | 232 | 152 | (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): | 155 | 166 | 169 | ||||||||
| 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) | 8.95 |
| 2023.07 | 178.9 (1) | 89.4 (2A) / 145.8 (2B) / 168.1 (2C) | (135.4 projected, -0.5) | (8.0) | |
| 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.
