The geomagnetic field was at quiet to unsettled levels on October 3. Solar wind speed at SOHO ranged between 341 and 397 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels. The above 10 MeV proton flux was at background levels at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 311.9 - increasing 63.0 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 177.49. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 177.49 on April 4, 2024). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.0). Three hour interval K indices: 11223122 (planetary), 01223332 (Boulder), 21113122 (Andenes).
The background x-ray flux is at the class C5 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 20 active regions using 2K resolution (SN: 510) and in 16 active regions using 1K resolution (SN: 311) SDO/HMI images.
AR 13835 [S20W79] reemerged with a tiny spot.
AR 13836 [S13W61] was mostly quiet and stable.
AR 13839 [S14W20] was quiet and stable.
AR 13841 [N13W22] decayed quickly and lost the magnetic delta
configuration. Flare activity decreased strongly after noon.
AR 13842 [S16W08] gained area in the leading spot section. The
largest penumbra has multiple magnetic delta configurations and another X
class flare is possible.
AR 13843 [S09W42] produced a major flare and has a magnetic delta
configuration in the trailing spot section.
AR 13844 [S15W30] displayed impressive growth and redeveloped a
magnetic delta configuration. A major flare is possible.
AR 13845 [N17W68] developed slowly and quietly.
AR 13847 [S28E35] decayed slowly and quietly.
AR 13848 [N13E56] was mostly unchanged and less active than during
the previous day.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10169 [S21W39] was quiet and stable.
S10171 [S04W15] was quiet and stable.
S10177 [N16W53] reemerged with tiny spots.
S10186 [N17E11] was quiet and stable.
S10189 [N10W09] was quiet and stable.
S10190 [S17E09] was quiet and stable.
New region S10191 [S06E78] rotated into view with large spots. It is
not yet clear if this is one or two spot groups.
New region S10192 [S10W00] emerged with tiny spots.
New region S10193 [S22E35] was observed with tiny spots in an
old plage area.
New region S10194 [S12E47] was observed with tiny spots in an old
plage area.
C2+ flares
Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
C4.9 | 01:06 | 13842 | GOES16 | ||
C5.9 | 01:58 | 13842 | GOES16 | ||
M1.1 | 02:34 | N13W08 | 13841 | GOES16 | |
C8.1 | 03:00 | 13844 | GOES16 | ||
C8.0 | 03:11 | 13841 | GOES16 | ||
M1.5 | 03:40 | 13842 | GOES16 | ||
C6.7 | 04:35 | 13848 | GOES18 | simultaneous flares in ARs 13842 and 13844 | |
C9.8 | 04:47 | 13841 | GOES18 | ||
C6.7 | 05:18 | 13841 | GOES18 | ||
C6.2 | 05:42 | 13835 | GOES18 | ||
C5.8 | 06:00 | 13841 | GOES18 | simultaneous flare in AR 13842 | |
C5.9 | 06:36 | 13841 | GOES18 | ||
C8.6 | 06:48 | N10E73 | 13848 | GOES16 | |
C5.9 | 07:36 | 13842 | GOES16 | ||
C5.2 | 07:41 | 13841 | GOES16 | ||
C5.5 | 07:54 | 13841 | GOES16 | ||
M1.5 | 08:28 | 13841 | GOES16 | ||
M1.5 | 08:36 | 13842 | GOES16 | ||
M1.1 | 09:22 | 13848 | GOES16 | simultaneous flare in AR 13841 | |
M1.0 | 10:15 | southeast limb | S10191 | GOES16 | |
C9.7 | 10:56 | 13842 | GOES16 | simultaneous flare in AR 13845 | |
C9.9 | 11:13 | 13842 | GOES16 | ||
C9.7 | 11:46 | 13842 | GOES16 | ||
M1.1 | 12:03 | 13844 | GOES16 | ||
X9.0 | 12:18 | 13842 | GOES16 | full halo CME, weak type IV and moderate type II radio sweep, largest flare of SC25 | |
M1.7 | 13:05 | 13844 | GOES16 | ||
M1.5 | 13:34 | 13848 | GOES16 | ||
M1.7 | 15:39 | 13844 | GOES16 | ||
M1.5 | 17:21 | S16W26 | 13844 | GOES16 | |
C9.6 | 18:47 | S10191 | GOES16 | ||
M1.1 | 19:20 | 13844 | GOES16 | simultaneous flare at the southwest limb | |
M6.7/2B | 20:28 | 13843 | GOES16 | moderate type II radio sweep | |
M2.3 | 21:41 | S15W26 | 13844 | GOES16 | |
C8.8 | 23:12 | 13842 | GOES16 | ||
M1.1 | 23:28 | 13842 | GOES16 | ||
C8.5 | 23:37 | S10191 | GOES16 |
October 3: A full halo CME aimed nearly straight at Earth was observed after the X9
flare in AR 13842. The CME could arrive either late on October 4 or on
October 5 and cause active to very severe geomagnetic storm levels.
October 2: No obviously Earth directed CMEs observed.
October 1: A faint, full halo CME was observed after the X7.1 flare
in AR 13842. The CME is likely to arrive on October 4 and cause unsettled to
major geogmagnetic storm
levels.
[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 small positive polarity trans equatorial coronal hole (CH1245) will likely rotate into an Earth facing position on October 4-5.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be at quiet levels most of October 3. Late in the day or during the first half of October 4 the October 1 CME is likely to arrive and cause unsettled to severe storm levels.
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 | ||||||||||
13835 | 2024.09.22 2024.09.22 |
1 | S22W84 | 0002 | AXX | location: S20W79 | |||||
13836 | 2024.09.22 2024.09.23 |
5 | 8 | 4 | S11W62 | 0010 | BXO | CRO |
location: S13W61 area: 0020 |
||
13845 | 2024.09.23 2024.10.01 |
1 | 9 | 3 | N17W74 | 0010 | AXX | CRO |
location: N17W68 area: 0025 SWPC position is way off |
||
13838 | 2024.09.24 2024.09.26 |
N15W54 | location: N16W51 | ||||||||
13840 | 2024.09.25 2024.09.27 |
N14W70 | location: N12W67 | ||||||||
13841 | 2024.09.25 2024.09.28 |
25 | 52 | 27 | N13W22 | 0200 | DAI | DAI | |||
13839 | 2024.09.26 2024.09.26 |
1 | 14 | 6 | S14W22 | 0060 | HSX | CSO |
area: 0090 location: S14W20 |
||
13842 | 2024.09.27 2024.09.28 |
35 | 63 | 38 | S15W08 | 0530 | EKC | EKC |
beta-gamma-delta area: 1250 location: S16W08 |
||
S10169 | 2024.09.27 | 8 | 1 | S21W39 | 0020 | AXX | |||||
S10170 | 2024.09.27 | N25W43 | |||||||||
S10171 | 2024.09.27 | 10 | 2 | S04W15 | 0020 | BXO | |||||
S10172 | 2024.09.27 | S03W44 | |||||||||
13843 | 2024.09.28 2024.09.29 |
19 | 24 | 16 | S09W39 | 0250 | EHI | EKC |
beta-gamma-delta location: S09W42 area: 0440 |
||
S10176 | 2024.09.28 | N17E14 | |||||||||
S10177 | 2024.09.28 | 2 | N16W53 | 0003 | AXX | ||||||
S10178 | 2024.09.28 | S14W17 | |||||||||
13844 | 2024.09.29 2024.09.30 |
25 | 41 | 25 | S15W30 | 0350 | DKI | EKC |
beta-gamma-delta area: 1030 |
||
S10180 | 2024.09.29 | N01W07 | |||||||||
13846 | 2024.09.30 2024.10.01 |
2 | S09W79 | 0020 | CRO |
location: S09W92 rotated out of view SWPC location is way off |
|||||
S10182 | 2024.09.30 | S07E15 | |||||||||
13847 | 2024.09.30 2024.10.01 |
1 | 4 | 3 | S28E31 | 0020 | HRX | CRO |
location: S28E35 |
||
S10184 | 2024.09.30 | N28W21 | |||||||||
13848 | 2024.10.01 2024.10.02 |
15 | 35 | 18 | N13E56 | 0330 | DKC | DKC |
beta-gamma area: 1510 |
||
S10186 | 2024.10.01 | 4 | 1 | N17E11 | 0007 | BXO | |||||
S10187 | 2024.10.01 | N34W30 | |||||||||
S10188 | 2024.10.01 | S34W08 | |||||||||
S10189 | 2024.10.02 | 3 | 1 | N10W09 | 0007 | BXO | |||||
S10190 | 2024.10.02 | 15 | 1 | S17E09 | 0020 | BXO | |||||
S10191 | 2024.10.03 | 6 | 4 | S06E78 | 0500 | CKO | |||||
S10192 | 2024.10.03 | 4 | 2 | S10W00 | 0010 | BXO | |||||
S10193 | 2024.10.03 | 3 | S22E35 | 0004 | AXX | ||||||
S10194 | 2024.10.03 | 4 | S12E47 | 0006 | AXX | ||||||
Total spot count: | 129 | 310 | 151 | ||||||||
Sunspot number: | 229 | 510 | 311 | (total spot count + 10 * number of spotted regions) | |||||||
Weighted SN: | 185 | 379 | 220 | (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): | 252 | 281 | 249 |
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 |
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 |
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) | 8.95 |
2023.07 | 176.4 | 182.2 | 160.0 | 124.6 (-0.7) | 8.15 |
2023.08 | 153.7 | 157.6 | 114.8 | 124.3 (-0.3) | 7.19 |
2023.09 | 154.4 | 156.0 | 134.2 | 124.0 (-0.3) | 14.26 |
2023.10 | 142.8 | 141.9 | 99.4 | 124.8 (+0.8) | 8.16 |
2023.11 | 153.5 | 150.2 | 105.4 | 127.8 (+3.0) | 12.20 |
2023.12 | 151.1 | 146.4 | 114.2 | 129.4 (+1.6) | 9.60 |
2024.01 | 164.6 | 159.3 | 126.0 | 131.1 (+1.7) | 5.46 |
2024.02 | 172.5 | 168.3 | 123.0 | 136.8 (+5.7) | 5.31 |
2024.03 | 154.4 | 152.9 | 103.7 | 141.3 (+4.5) | 11.03 |
2024.04 | 161.3 | 162.6 | 136.5 | (145.3 projected, +4.0) | 9.69 |
2024.05 | 187.7 | 191.9 | 171.7 | (151.6 projected, +6.3) | 23.56 (SC25 peak) |
2024.06 | 184.3 | 190.2 | 164.2 | (155.5 projected, +3.9) | 10.24 |
2024.07 | 196.6 |
203.0 | 196.5 | (158.4 projected, +2.9) | 7.13 |
2024.08 | 246.1 (cycle peak) |
252.2 | 215.5 (SC25 peak) | (160.4 projected, +2.0) | 15.96 |
2024.09 | 195.7 | 197.8 | 141.4 | (163.1 projected, +2.7) | 15.3 |
2024.10 | 277.0 (1) | 20.0 (2A) / 206.3 (2B) / 194.9 (2C) | (165.4 projected, +2.3) | (6.0) | |
2024.11 | (163.7 projected, -1.7) | ||||
2024.12 | (160.7 projected, -3.0) | ||||
2025.01 | (156.3 projected, -4.4) | ||||
2025.02 | (149.6 projected, -6.7) | ||||
2025.03 | (144.8 projected, -4.8) | ||||
2025.04 | (141.6 projected, -3.2) |
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
Sunspot counts in August 2024 were much higher than during any previous solar cycle 25 month. In comparison only 3 months during solar cycle 23 had higher SSN. Sunspot counts in early September are still high, although lower than in the beginning of August. With at least 5 consecutive months of high sunspot counts the projected peak for the smoothed ISN (365 days smoothing) has increased significantly to above 160 and could easily surpass 170 if the current activity lasts through October. The month of the peak is likely to occur sometime between July and November 2024.
--------------------------------------------------------------------------------------
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.