The geomagnetic field was quiet to active on May 7 under the influence of effects associated with CH1145 and a weak CME embedded in the high speed stream from CH1145. Solar wind speed at SOHO ranged between 401 and 511 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels. Solar wind density increased slowly all day and peaked at 14:41 UT at DSCOVR. Then a CIR associated with CH1145 arrived and solar wind density decreased quickly. What was likely a component from the May 4 or 5 CME arrived near the same time as a weak sudden impulse was recorded. The CME influence appeared to end at 02 UT on May 8 as the IMF has been in an away sector since then (consistent with the influence of positive polarity high speed stream).
Solar flux density measured at 20h UT on 2.8 GHz was 157.2 - increasing 17.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 140.50. In comparison SC24 peaked on June 28, 2014 at 145.50). The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.1). Three hour interval K indices: 12212422 (planetary), 13333423 (Boulder), 33322422 (Andenes).
The background x-ray flux is at the class B8 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 315) and in 11 active regions using 1K resolution (SN: 204) SDO/HMI images.
Region 13293 [N11W18] decayed slowly and
was mostly quiet. C1 flares: C1.3 @ 03:52, C1.8 @ 10:04, C1.9 @ 11:09, C1.5
@ 12:06, C1.1 @ 20:16 UT
Region 13294 [S07E05] was quiet and stable.
Region 13296 [N16W07] developed in the southern central spot section
with resulted in polarity intermixing. Long duration M flares were recorded
towards the end of the day and one or two Earth directed halo CMEs were
observed soon afterwards. C1 flares: C1.6 @ 21:05 UT
Region 13297 [N08E10] gained spots, particularly in an area just
ahead of the large main penumbra. The probability of a major flare is
increasing. C1 flares: C1.2 @ 01:50, C1.0 @ 02:24 UT
Region 13299 [S07E28] decayed slowly and quietly.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8505 [N19W13] reemerged with tiny spots.
S8528 [S05E31] developed slowly as new flux emerged to the south of
the original spots.
S8529 [S25E39] was quiet and stable.
S8530 [S19W18] was quiet and stable.
S8533 [N17E23] reemerged with tiny spots.
New region S8540 [S10E79] rotated into view
with a tiny spot.
New region S8541 [S21E26] was observed with tiny spots in an old
plage area.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.1 | 10:10 | 13293 | GOES16 | ||
| C2.5 | 11:22 | 13296 | GOES16 | ||
| M1.5 | 22:34 | 13296 | GOES16 | LDE. CME | |
| M1.6 | 23:22 | 13296 | GOES16 | LDE. CME |
May 7: Halo CMEs were observed after the M1
long duration events in AR 13296 towards the end of the day. The CMEs could
reach Earth on May 10 and cause unsettled to major storm conditons.
May 6: No obviously Earth directed CMEs were
observed.
May 5: CMEs associated with an M2 flare in AR 13296 at 08:01 UT and a
C9.5 flare in AR 13297 at 07:06 could reach Earth on May 7-8 and cause
unsettled to minor storm conditions. Both flares may have been triggered by a
large filament eruption in the northeast quadrant (and extending beyond the
northeast limb).
[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 (CH1145) rotated across the central meridian on May 4. Another northern hemisphere coronal hole (CH1146) will likely become Earth facing on May 8-9, but may be too far to the north to cause a geomagnetic disturbance.
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 minor storm conditions are possible on May 8-9 due to effects from CH1145 and CME effects. When the May 7 CME arrives, probably on May 10, unsettled to major storm conditions will be likely until May 11.
| 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 | ||||||||||
| 13289 | 2023.04.25 2023.04.25 |
N20W81 |
|
||||||||
| 13292 | 2023.04.25 2023.04.27 |
N14W80 | location: N17W72 | ||||||||
| S8505 | 2023.04.29 | 4 | 3 | N19W29 | 0010 | AXX |
 |
 |
|||
| S8506 | 2023.04.29 | S10W52 | |||||||||
| 13293 | 2023.04.30 2023.04.30 |
10 | 43 | 22 | N13W19 | 0130 | DAI | EAI |
 |
 |
location: N11W18 |
| 13295 | 2023.04.30 2023.05.02 |
N16W87 | |||||||||
| S8509 | 2023.04.30 | S25W13 | |||||||||
| S8514 | 2023.04.30 | N33W48 | |||||||||
| S8515 | 2023.05.01 | S11W36 | |||||||||
| 13294 | 2023.05.01 2023.05.02 |
2 | 11 | 5 | S08E04 | 0120 | HSX | CSO |
 |
 |
area: 0190 location: S07E05 |
| 13296 | 2023.05.02 2023.05.02 |
12 | 26 | 18 | N16W06 | 0280 | EKC | DAI |
 |
 |
beta-gamma area: 0330 reversed polarities |
| 13297 | 2023.05.02 2023.05.02 |
18 | 73 | 34 | N08E10 | 0460 | EKC | EKC |
 |
 |
beta-gamma area: 0600 |
| S8523 | 2023.05.02 | N06W39 | |||||||||
| 13298 | 2023.05.03 2023.05.04 |
S16W08 | location: S15W05 | ||||||||
| 13299 | 2023.05.03 2023.05.04 |
7 | 7 | 1 | S06E29 | 0060 | CAO | CAO |
 |
|
location: S07E28 |
| S8527 | 2023.05.03 | N23W56 | |||||||||
| S8528 | 2023.05.04 | 11 | 6 | S05E31 | 0025 | CRO |
 |
 |
|||
| S8529 | 2023.05.04 | 1 | 1 | S23E39 | 0008 | HRX |
 |
 |
|||
| S8530 | 2023.05.04 | 4 | 1 | S19W18 | 0010 | AXX |
 |
 |
|||
| S8532 | 2023.05.05 | S27W37 | |||||||||
| S8533 | 2023.05.06 | 7 | N17E23 | 0010 | AXX |
 |
|||||
| S8535 | 2023.05.06 | N05W44 |
 |
||||||||
| S8536 | 2023.05.06 | N11E29 |
 |
||||||||
| S8537 | 2023.05.06 | N29E23 |
 |
||||||||
| S8538 | 2023.05.06 | S30W31 |
 |
||||||||
| S8540 | 2023.05.07 | 1 | 1 | S10E79 | 0003 | AXX |
 |
||||
| S8541 | 2023.05.07 | 7 | 2 | S21E26 | 0015 | BXO |
 |
||||
| Total spot count: | 49 | 195 | 94 | ||||||||
| Sunspot number: | 99 | 315 | 204 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 84 | 231 | 130 | (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): | 109 | 173 | 163 | ||||||||
| 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 |
| 2021.09 | 87.0 | 88.2 | 51.3 | 40.2 (+4.8) | 6.33 |
| 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 | (100.4 projected, +1.7) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | (104.1 projected, +3.7) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (110.1 projected, +6.0) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 110.9 | (115.2 projected, +5.1) | 14.48 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 122.6 | (118.3 projected, +3.1) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 96.4 | (123.7 projected, +5.4) | 13.3 |
| 2023.05 | 156.3 (1) | 25.5 (2A) / 113.0 (2B) / 151.8 (2C) | (129.3 projected, +5.6) | (9.8) | |
| 2023.06 | (132.5 projected, +3.2) | ||||
| 2023.07 | (132.0 projected, -0.5) | ||||
| 2023.08 | (133.0 projected, +1.0) | ||||
| 2023.09 | (136.4 projected, +3.4) | ||||
| 2023.10 | (138.3 projected, +1.9) | ||||
| 2023.11 | (141.4 projected, +3.1) | ||||
| 2023.12 | (142.5 projected max SC25) | ||||
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: SIDC-SILSO.
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.
