The geomagnetic field was quiet to unsettled on June 21, weakly under the influence of effects related to CH1153/CH1154. Solar wind speed at SOHO ranged between 413 and 473 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 176.4 - increasing 24.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 144.15. 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: 6.3). Three hour interval K indices: 22111113 (planetary), 33122223 (Boulder), 43211115 (Andenes).
The background x-ray flux is at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 20 active regions using 2K resolution (SN: 425) and in 17 active regions using 1K resolution (SN: 282) SDO/HMI images.
Region 13333 [S10W61] decayed slowly and was
mostly quiet.
Region 13334 [N17W25] developed slowly and quietly.
Region 13335 [S14W33] gained some small spots near the main penumbra
and has polarity intermixing. An M class flare is possible.
Region 13337 [N19W09] remerged with many spots and polarity
intermixing. An M class flare is possible.
Region 13338 [N11W10] decayed slowly and quietly.
Region 13339 [S20E18] was mostly quiet and stable.
Region 13340 [N22E19] developed slowly and was mostly quiet.
Region 13341 [S16E49] continued to produce flares, although with a
lower frequency than during the previous day. Further M class flaring is
likely.
Region 13342 [S23W82] rotated partly out of view producing a few C
flares. C1 flares: C1.9 @ 22:40 UT
Region 13344 [N23W59] was quiet and stable.
Region 13345 [N09E45] was mostly quiet and stable.
New region 13346 [N08E22] emerged on June 20 and was numbered by SWPC
the next day.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S8682 [N17E19] was quiet and stable.
S8686 [S12E68] was quiet and stable.
S8687 [S28E37] was quiet and stable.
New region S8688 [S27E02] was observed with
tiny spots in an old plage area.
New region S8689 [N15E64] emerged with a tiny spot.
New region S8690 [S19E00] emerged with several spots.
New region S8691 [S07W20] emerged with a tiny spot.
New region S8692 [S30E74] rotated into view
with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.2 | 00:08 | 13342 | GOES16 | ||
| C2.5 | 00:47 | S20W78 | 13342 | GOES16 | |
| C2.5 | 01:21 | 13341 | GOES16 | ||
| C2.3 | 02:19 | behind SW limb | 13332 | GOES16 | |
| C2.4 | 02:39 | 13341 | GOES16 | ||
| C3.5 | 03:15 | S20W78 | 13342 | GOES16 | |
| C3.4 | 03:34 | behind SW limb | 13332 | GOES16 | |
| C2.8 | 03:50 | 13339 | GOES16 | ||
| C3.1 | 04:39 | 13336 | GOES16 | ||
| C2.1 | 05:24 | behind SW limb | 13332 | GOES16 | |
| C2.1 | 06:41 | 13342 | GOES16 | ||
| C2.1 | 07:06 | 13340 | GOES16 | ||
| C2.0 | 07:28 | 13342 | GOES16 | ||
| C3.3 | 07:45 | 13340 | GOES16 | ||
| C2.4 | 09:07 | 13342 | GOES16 | ||
| C3.0 | 09:25 | 13337 | GOES16 | ||
| C5.1 | 10:49 | S22E64 | 13341 | GOES16 | |
| M1.1/1N | 12:44 | S14E59 | 13341 | GOES16 | |
| M1.0 | 15:38 | N19W06 | 13337 | GOES16 | weak type II radio sweep |
| C2.3 | 16:56 | 13342 | GOES16 | ||
| C2.1 | 18:15 | 13340 | GOES16 | ||
| C2.8 | 18:22 | 13339 | GOES16 | ||
| C2.1 | 18:43 | 13341 | GOES16 | simultaneous flare in AR 13342 | |
| C4.4 | 20:27 | 13341 | GOES16 | ||
| C5.5 | 20:48 | 13337 | GOES16 |
June 19, 21: No obviously Earth directed CMEs were
observed.
June 20: A CME associated with X1 flare at 17:09 UT in AR 13341 may
have Earth directed components. In that case a weak shock and unsettled to
minor storm intervals are possible on June 23-24.
[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 (CH1155) could become Earth facing on June 23. CH1155 lost a substantial part of its area on June 21 due to the development of AR 13346.
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.
Quiet to unsettled geomagnetic conditions are expected for June 22. If any components of the June 20 CME are Earth directed, unsettled to minor storm conditions will be possible on June 23-24.
| 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 | ||||||||||
| 13333 | 2023.06.12 2023.06.13 |
5 | 6 | 4 | S11W57 | 0080 | CAO | CAO |
 |
 |
area: 0050 |
| 13334 | 2023.06.13 2023.06.13 |
13 | 5 | N16W35 | 0035 | DRO |
 |
 |
location: N17W25 SWPC added a duplicate region on June 19, AR 13343 |
||
| 13336 | 2023.06.13 2023.06.14 |
S19W30 |
 |
location: S21W29 northern part merged with AR 13335 on June 21 |
|||||||
| 13335 | 2023.06.13 2023.06.14 |
17 | 42 | 20 | S15W28 | 0220 | EAI | EHI |
 |
 |
area: 0330 location: S14W33 |
| S8661 | 2023.06.14 | N22W23 | |||||||||
| 13337 | 2023.06.14 2023.06.15 |
10 | 27 | 15 | N20W07 | 0120 | CSO | DRI |
 |
beta-gamma location: N19W09 |
|
| 13338 | 2023.06.14 2023.06.15 |
5 | 16 | 7 | N11W08 | 0040 | CSO | DAO |
 |
 |
area: 0080 |
| S8670 | 2023.06.16 | N07W00 | |||||||||
| 13339 | 2023.06.16 2023.06.17 |
5 | 21 | 13 | S18E15 | 0140 | CAO | CSO |
 |
 |
area: 0290 location: S20E18 |
| 13340 | 2023.06.17 | 12 | 28 | 12 | N21E19 | 0120 | CAO | DAI |
 |
 |
beta-gamma area: 0160 location: N22E19 |
| 13342 | 2023.06.17 2023.06.19 |
6 | 2 | 2 | S21W84 | 0200 | DAO | HAX |
 |
 |
location: S23W82 |
| S8676 | 2023.06.18 | S13E30 |
 |
||||||||
| 13341 | 2023.06.18 2023.06.19 |
7 | 22 | 10 | S15E48 | 0190 | CSO | CSI |
 |
 |
beta-gamma location: S16E49 area: 0320 |
| S8678 | 2023.06.18 | S01W27 | |||||||||
| 13343 | 2023.06.19 | N16W27 | this is a duplicate of AR 13334 | ||||||||
| 13344 | 2023.06.19 2023.06.20 |
3 | 10 | 5 | N22W59 | 0080 | DAO | DAO |
 |
 |
|
| S8680 | 2023.06.19 | S16E13 | |||||||||
| S8682 | 2023.06.19 | 4 | 3 | N17E19 | 0020 | DRO |
 |
 |
|||
| 13345 | 2023.06.19 2023.06.20 |
5 | 10 | 4 | N09E48 | 0080 | DSO | DAO |
 |
 |
location: N09E45 |
| 13346 | 2023.06.20 2023.06.21 |
5 | 8 | 3 | N08E22 | 0020 | CSO | DRO |
 |
 |
area: 0035 |
| S8686 | 2023.06.20 | 3 | 2 | S12E68 | 0015 | CRO |
 |
 |
|||
| S8687 | 2023.06.20 | 1 | N27E32 | 0001 | AXX |
 |
 |
||||
| S8688 | 2023.06.21 | 5 | 3 | S27E02 | 0012 | AXX |
 |
||||
| S8689 | 2023.06.21 | 1 | 1 | N15E64 | 0004 | AXX |
 |
||||
| S8690 | 2023.06.21 | 4 | 3 | S19E00 | 0015 | CRO |
 |
||||
| S8691 | 2023.06.21 | 1 | S07W20 | 0001 | AXX |
 |
|||||
| S8692 | 2023.06.21 | 1 | S30E74 | 0001 | AXX |
 |
|||||
| Total spot count: | 80 | 225 | 112 | ||||||||
| Sunspot number: | 190 | 425 | 282 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 135 | 293 | 180 | (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): | 209 | 234 | 226 | ||||||||
| 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 |
| 2021.10 | 88.9 | 88.3 | 37.4 | 45.2 (+5.0) | 7.38 |
| 2021.11 | 86.2 | 84.4 | 34.8 | 50.8 (+5.6) | 9.83 |
| 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 | (105.8 projected, +4.8) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (112.2 projected, +6.4) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 110.9 | (117.0 projected, +4.8) | 14.48 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 122.6 | (120.1 projected, +3.1) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 96.4 | (125.5 projected, +5.4) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.9 | (131.2 projected, +5.7) | 10.67 |
| 2023.06 | 162.3 (1) | 94.3 (2A) / 134.7 (2B) / 171.4 (2C) | (134.3 projected, +3.1) | (8.0) | |
| 2023.07 | (133.8 projected, -0.5) | ||||
| 2023.08 | (134.8 projected, +1.0) | ||||
| 2023.09 | (138.2 projected, +3.4) | ||||
| 2023.10 | (140.1 projected, +1.9) | ||||
| 2023.11 | (142.7 projected max SC25) | ||||
| 2023.12 | (142.6 projected, -0.1) | ||||
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.
