The geomagnetic field was quiet to unsettled on June 18, weakly under the influence of effects related to CH1153. Solar wind speed at DSCOVR ranged between 370 and 462 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 164.1 - increasing 2.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 143.85. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.8). Three hour interval K indices: 32122232 (planetary), 23132323 (Boulder), 55233353 (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 15 active regions using 2K resolution (SN: 347) and in 13 active regions using 1K resolution (SN: 217) SDO/HMI images.
Region 13331 [S22W80] decayed slowly and
quietly.
Region 13332 [S09W68] was quiet and stable.
Region 13333 [S11W18] was mostly quiet and stable. The region could
produce a minor M class flare.
Region 13334 [N16E12] was mostly quiet and stable.
Region 13335 [S14E08] lost the magnetic delta and was mostly quiet. M
class flares are possible. C1 flares: C1.4 @ 03:02 UT
Region 13336 [S21E15] has many tiny spots. Despite the lack of
obvious magnetic complexity, the region was the source of both of the M
class flares recorded during the day. C1 flares: C1.5 @ 11:24 UT
Region 13337 [N18E31] reemerged with tiny spots.
Region 13338 [N11E29] began to decay and was quiet.
Region 13339 [S19E57] was quiet and stable.
New region 13340 [N22E58] emerged on June 17 and was numbered by SWPC
the next day as the region developed further. C1 flares: C1.7 @ 02:08, C1.5
@ 12:21, C1.8 @ 19:06 UT
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S8669 [N17W44] was quiet and stable.
S8675 [S21W46] developed slowly and quietly.
New region S8676 [S12E69] emerged before noon and was quiet.
New region S8677 [S12E86] rotated partly into view. C1 flares:
C1.8 @ 06:42, C1.9 @ 16:21, C1.9 @ 23:21, C1.8 @ 23:58 UT
New region S8678 [S01E12] emerged with a tiny spot.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.0 | 00:12 | 13335 | GOES16 | ||
| M1.3 | 00:31 | 13336 | GOES16 | ||
| C2.5 | 05:05 | 13334 | GOES16 | ||
| C2.1 | 05:35 | S15E18 | 13335 | GOES16 | |
| C2.0 | 07:57 | 13340 | GOES16 | ||
| C2.1 | 09:36 | 13336 | GOES16 | ||
| M2.5/2N | 13:53 | 13336 | GOES16 | LDE, CME | |
| C2.1 | 22:00 | 13340 | GOES16 | ||
| C2.7 | 22:39 | S8677 | GOES16 | ||
| C3.0 | 22:47 | 13336 | GOES16 |
June 16-18: 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 trans equatorial coronal hole (CH1153) rotated across the central meridian on June 12-17. A southern hemisphere coronal hole (CH1154) was Earth facing on June 16-17, however, CH1154 closed on June 17.
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.
Quiet to unsettled geomagnetic conditions are expected for June 19-21 due to weak effects from CH1153 and CH1154.
| 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 | ||||||||||
| 13331 | 2023.06.06 2023.06.07 |
2 | 2 | 1 | S23W80 | 0050 | HSX | HRX |
 |
 |
area: 0025 |
| 13332 | 2023.06.07 2023.06.07 |
2 | 6 | 3 | S10W71 | 0010 | AXX | CRO |
 |
 |
location: S09W68 area: 0025 |
| S8639 | 2023.06.09 | S13W38 | |||||||||
| S8646 | 2023.06.10 | S30W23 | |||||||||
| S8649 | 2023.06.10 | S20W34 | |||||||||
| S8651 | 2023.06.11 | S12W51 | |||||||||
| S8652 | 2023.06.11 | N18W24 | |||||||||
| 13333 | 2023.06.12 2023.06.13 |
13 | 38 | 22 | S11W19 | 0200 | EAI | EAI |
 |
 |
beta-gamma |
| 13334 | 2023.06.13 2023.06.13 |
24 | 5 | N16E07 | 0040 | BXO |
 |
 |
location: N16E12 |
||
| 13336 | 2023.06.13 2023.06.14 |
5 | 24 | 7 | S22E17 | 0030 | CRO | CRO |
 |
 |
area: 0050 location: S21E15 |
| 13335 | 2023.06.13 2023.06.14 |
18 | 38 | 20 | S15E10 | 0360 | EKI | EHI |
 |
 |
beta-gamma area: 0420 location: S14E08 |
| S8661 | 2023.06.14 | N22E16 | |||||||||
| 13337 | 2023.06.14 2023.06.15 |
7 | 1 | N17E31 | 0010 | BXO |
 |
location: N18E31 | |||
| 13338 | 2023.06.14 2023.06.15 |
6 | 20 | 10 | N11E31 | 0120 | CAO | EAO |
 |
 |
area: 0170 location: N11E29 |
| S8665 | 2023.06.15 | S13W47 | |||||||||
| S8667 | 2023.06.15 | N27W30 | |||||||||
| S8668 | 2023.06.15 | N17W56 | |||||||||
| S8669 | 2023.06.16 | 9 | 4 | N17W44 | 0020 | CRO |
 |
 |
|||
| S8670 | 2023.06.16 | N07E39 | |||||||||
| 13339 | 2023.06.16 2023.06.17 |
1 | 1 | 1 | S19E56 | 0120 | HSX | HHX |
 |
 |
area: 0270 location: S19E57 |
| S8672 | 2023.06.17 | N20W38 |
 |
||||||||
| 13340 | 2023.06.17 | 6 | 16 | 6 | N23E59 | 0100 | CAO | CAO |
 |
 |
|
| S8674 | 2023.06.17 | S23W32 |
 |
||||||||
| S8675 | 2023.06.17 | 8 | 6 | S21W46 | 0030 | CRO |
 |
 |
|||
| S8676 | 2023.06.18 | 2 | 1 | S12E69 | 0008 | CRO |
 |
||||
| S8677 | 2023.06.18 | 1 | S12E86 | 0010 | AXX |
 |
|||||
| S8678 | 2023.06.18 | 1 | S01E12 | 0002 | AXX |
 |
|||||
| Total spot count: | 53 | 197 | 87 | ||||||||
| Sunspot number: | 133 | 347 | 217 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 91 | 250 | 140 | (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): | 146 | 191 | 174 | ||||||||
| 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 | 160.2 (1) | 76.7 (2A) / 127.9 (2B) / 164.4 (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.
