The geomagnetic field was at very severe to extremely severe storm levels on May 11. Another CME was observed arriving at SOHO at 17:49 UT with a subsequent increase in solar wind speed to above 1000 km/sec. May 11, 2024 now ranks as the geomagnetically second most disturbed day in recorded history. November 13, 1960 is the only day ahead when the daily average Ap was 280. The minimum Kp during the day was 8, the first time this has happened. The high latitude magnetometer at Andenes recorded major to very severe storm levels. The above 10 MeV proton flux was at 42 pfu at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 213.7 - increasing 35.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 159.34. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 159.34 on November 11, 2023). The Potsdam WDC planetary A index was 274 (STAR Ap - based on the mean of three hour interval ap indices: 274.3). Three hour interval K indices: 98899888 (planetary), 97997666 (Boulder), 78878687 (Andenes).
The background x-ray flux is at the class C7 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 18 active regions using 2K resolution (SN: 401) and in 15 active regions using 1K resolution (SN: 272) SDO/HMI images.
Region 13664 [S17W71] was quiet and
stable.
Region 13667 [N27W17] was quiet and stable.
Region 13670 [N17E02] decayed slowly and quietly.
Region 13671 [N20E05] was quiet and stable.
Region 13672 [N19E34] was mostly quiet and stable.
New region 13673 [S09E55] rotated into view on May 9 and was numbered
by SWPC 2 days later.
New region 13674 [S13E66] rotated into view on May 10 and received
its NOAA number the following day.
New region 13675 [S15W28] emerged on May 9 with SWPC numbering the
region 2 days later when growth intensified.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9676 [S19W60] lost several magnetic delta configurations, as well as
area and spots, however,
the largest delta remains and consists of a large area of positive polarity
flux sandwiched between negative polarity areas. Another X class flare is
possible.
S9689 [S10E46] was quiet and stable.
S9692 [N23E04] developed slowly and was mostly quiet.
S9697 [S21E23] developed further and was quiet.
New region S9700 [S20E50] emerged with tiny spots.
New region S9701 [N08E80] emerged near the northeast limb with tiny
spots.
New region S9702 [S09E09] emerged with tiny spots.
New region S9703 [S03W25] emerged with tiny spots.
New region S9704 [N10E12] was observed with tiny spots in an
old plage area.
New region S9705 [S23E41] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C7.0 | 00:28 | behind northwest limb | 13663 | GOES16 | |
| M1.0 | 01:05 | S9676 | GOES16 | ||
| X5.8/2B | 01:23 | S15W45 | S9676 | GOES16 | full halo CME moderate type IV and strong type II radio sweeps |
| M1.1 | 03:32 | S9676 | GOES16 | ||
| M1.0 | 03:59 | S9676 | GOES16 | ||
| M1.0 | 04:20 | S9676 | GOES16 | ||
| M1.4 | 04:40 | S9676 | GOES16 | ||
| M1.1 | 05:24 | S9676 | GOES16 | ||
| M1.1 | 05:50 | S9676 | GOES16 | ||
| M1.2 | 07:42 | S9676 | GOES16 | ||
| M1.2 | 08:07 | S9676 | GOES16 | ||
| M1.3 | 08:18 | 13672 | GOES16 | ||
| M1.4 | 08:56 | S9676 | GOES16 | ||
| M1.7 | 09:14 | S9676 | GOES16 | ||
| M3.1 | 10:18 | S9676 | GOES16 | ||
| M1.6 | 10:56 | behind northwest limb | 13663 | GOES16 | SWPC attributes this to AR 13664 (S9676) |
| X1.5 | 11:44 | S9676 | GOES16 | ||
| M2.3 | 12:38 | S9676 | GOES16 | ||
| M2.0 | 12:59 | S9676 | GOES16 | ||
| M1.2 | 13:34 | S9676 | GOES16 | ||
| M1.8/1N | 13:49 | S9676 | GOES16 | ||
| M1.3 | 14:18 | S9676 | GOES16 | ||
| M1.4 | 14:57 | S9676 | GOES16 | ||
| M6.9 | 15:13 | behind northeast limb | GOES16 | ||
| M8.8/2N | 15:25 | S15W49 | S9676 | GOES16 | |
| M2.8 | 16:55 | S9676 | GOES16 | ||
| M1.1 | 17:41 | S9676 | GOES16 | ||
| C6.6 | 19:01 | S9676 | GOES16 | ||
| C5.3 | 19:21 | S9676 | GOES16 | ||
| C5.5 | 19:32 | S9676 | GOES16 | simultaneous flare in AR 13670 | |
| C7.2 | 19:47 | N16E56 | 13672 | GOES16 | |
| C6.5 | 20:04 | S9676 | GOES16 | ||
| M1.2 | 20:41 | S9676 | GOES16 | ||
| C9.4 | 21:07 | S9676 | GOES16 | ||
| C7.3 | 21:42 | S9676 | GOES16 | ||
| C7.8 | 21:58 | S9676 | GOES16 | ||
| C6.2 | 22:39 | behind northeast limb | GOES16 | ||
| C6.6 | 23:29 | S9676 | GOES16 |
May 11: The X5 flare in AR
S9676 at 01:23 UT was associated with a bright halo CME.
May 10: The X3 flare in AR
S9676 at 06:54 UT was associated with another halo CME.
May 9: A full halo CME was observed following an X2 flare in AR
S9676.
[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 positive polarity northern hemisphere coronal hole (CH1221) was Earth facing on May 8-9.
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 to useless. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be at active to severe storm levels on May 12-14 due to inbound CMEs from flare activity in AR S9676.
| Coronal holes (1) | Coronal mass ejections (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 | ||||||||||
| 13664 | 2024.04.30 2024.05.01 |
43 | 1 | 1 | S18W62 | 2100 | FKC | HSX |
 |
 |
area: 0140 location: S17W71 SWPC includes AR S9676 in this spot group |
| 13665 | 2024.05.01 2024.05.02 |
S05W60 |
 |
location: S06W41 SWPC location is way off |
|||||||
| 13669 | 2024.05.02 2024.05.05 |
S09W41 |
 |
location: S10W34 |
|||||||
| 13668 | 2024.05.03 2024.05.05 |
S15W55 | merged with AR S9676 on May 9 | ||||||||
| S9670 | 2024.05.03 | N04W50 | |||||||||
| 13667 | 2024.05.03 2024.05.04 |
1 | 4 | 3 | N27W18 | 0140 | HSX | HAX |
 |
 |
area: 0230 location: N27W17 |
| S9672 | 2024.05.03 | S33W47 | |||||||||
| S9676 | 2024.05.05 | 81 | 49 | S19W60 | 2360 | FKC |
 |
 |
beta-gamma-delta | ||
| 13670 | 2024.05.05 2024.05.06 |
4 | 15 | 5 | N18E02 | 0030 | CSO | BXO |
 |
 |
location: N17E02 |
| S9679 | 2024.05.06 | N15W33 | |||||||||
| 13671 | 2024.05.06 2024.05.09 |
7 | 11 | 7 | N24E04 | 0030 | CRO | DRO |
 |
 |
location: N20E05 SWPC location on May 10 was N19E17, the new location seems to be that of AR S9692 |
| S9682 | 2024.05.07 | N15W43 | |||||||||
| S9683 | 2024.05.07 | S26W34 | |||||||||
| S9684 | 2024.05.07 | S24W02 | |||||||||
| 13672 | 2024.05.08 2024.05.09 |
4 | 16 | 10 | N18E30 | 0090 | DAO | DSO |
 |
 |
beta-gamma location: N19E34 area: 0130 |
| S9687 | 2024.05.08 | S07W24 | |||||||||
| S9689 | 2024.05.08 | 3 | 1 | S10E46 | 0005 | BXO |
 |
 |
|||
| 13675 | 2024.05.09 2024.05.11 |
5 | 12 | 6 | S15W29 | 0030 | CRO | DAO |
 |
 |
area: 0100 location: S15W28 |
| 13673 | 2024.05.09 2024.05.11 |
1 | 1 | 1 | S09E54 | 0030 | HSX | HSX |
 |
 |
area: 0050 location: S09E55 |
| S9692 | 2024.05.09 | 28 | 15 | N23E04 | 0070 | DRI |
 |
 |
|||
| S9693 | 2024.05.09 | N13W32 |
 |
||||||||
| S9694 | 2024.05.09 | S04E13 | |||||||||
| S9695 | 2024.05.09 | S21W51 |
 |
||||||||
| S9696 | 2024.05.09 | S30W36 | |||||||||
| S9697 | 2024.05.10 | 24 | 16 | S21E23 | 0130 | DRI |
 |
 |
|||
| 13674 | 2024.05.10 | 3 | 11 | 5 | S14E64 | 0080 | CSO | DAO |
 |
 |
area: 0170 location: S13E66 |
| S9700 | 2024.05.11 | 2 | S20E50 | 0002 | AXX |
 |
|
||||
| S9701 | 2024.05.11 | 3 | 1 | N08E80 | 0006 | BXO |
 |
|
|||
| S9702 | 2024.05.11 | 4 | 1 | S09E09 | 0008 | BXO |
 |
|
|||
| S9703 | 2024.05.11 | 2 | 1 | S03W25 | 0006 | BXO |
 |
|
|||
| S9704 | 2024.05.11 | 2 | N10E12 | 0002 | BXO |
 |
|
||||
| S9705 | 2024.05.11 | 1 | S23E41 | 0002 | AXX |
 |
|
||||
| Total spot count: | 68 | 221 | 122 | ||||||||
| Sunspot number: | 148 | 401 | 272 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 109 | 270 | 171 | (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): | 163 | 221 | 218 | ||||||||
| 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 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.9 (+2.4) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.2 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.7 (+5.5) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 144.4 | 113.3 (+6.6) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 111.3 | 117.8 (+3.5) | 14.48 (current SC25 peak) |
| 2023.03 | 157.2 | 155.6 | 123.3 | 121.1 (+3.3) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 97.6 | 122.9 (+1.8) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.4 | 124.2 (+1.3) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.3 (+1.1) (SC25 solar max candidate) |
8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | 124.4 (-0.9) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | 124.1 (-0.3) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | 123.9 (-0.2) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | 124.8 (+0.9) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | (125.2 projected, +0.4) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | (121.9 projected, -3.3) | 9.60 |
| 2024.01 | 164.6 | 159.3 | 123.0 | (118.5 projected, -3.4) | 5.46 |
| 2024.02 | 172.5 | 168.3 | 124.7 | (117.7 projected, -0.8) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 104.9 | (117.1 projected, -0.6) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (117.1 projected, -0.0) | 9.69 |
| 2024.05 | 186.3 (1) | 49.9 (2A) / 140.5 (2B) / 198.8 (2C) | (118.3 projected, +1.2) | (45.0) | |
| 2024.06 | (117.4 projected, -0.9) | ||||
| 2024.07 | (115.7 projected, -1.7) | ||||
| 2024.08 | (113.8 projected, -1.9) | ||||
| 2024.09 | (112.5 projected, -1.3) | ||||
| 2024.10 | (111.1 projected, -1.4) | ||||
| 2024.11 | (108.6 projected, -2.5) | ||||
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
The big increase in sunspot counts during the April 14-27 interval caused a major uptick in the smoothed SNs and solar flux. It's not yet clear when the next peak will be, anytime between October 28 and December 20, 2023 looks possible. The 365d smoothed solar flux exceeded the June 27 peak on October 28, while the 365d smoothed ISN and NOAA SN both exceeded the June 2023 peak in late October 2023. It should be noted that the current peak using 13-month smoothing is still in June 2023.
--------------------------------------------------------------------------------------
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.
