The geomagnetic field was at quiet to active levels on January 18 under the influence of effects associated with CH1340. Solar wind speed at SOHO ranged between 460 and 711 km/sec, averaging 578 km/sec (-128 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at unsettled to severe storm levels. The above 10 MeV proton flux was at background levels until after the X1 flare in AR 14341. At approximately 20:05 UT the above 10 MeV proton flux began to increase and has so far peaked at 84 pfu at 02:20 UT on January 19.
Solar flux density measured at 22h UT on 2.8 GHz was 186.6 - increasing 53.3 over the previous solar rotation. The measurements at 18 and 20h UT were enhanced by the long duration X1 event in AR 14341. The measurement at 22h UTC may have been somewhat enhanced as well, however, it is the only measurement of the day that appears usable.
The 365 day average solar flux at 1 AU was 152.20 (183 days ago). The 81 day average solar flux at 1 AU was 143.9 (41 days ago, this is 47.3% of the total SC25 solar flux range from the max 81 day average peak on September 4, 2024 at 227.3 and an average 81 day flux of 69 at solar minimum). SC25 365d peak: 195.9 on October 13, 2024.
The Potsdam WDC planetary A index was 14 (STAR Ap - based on the average of three hour interval ap indices: 14.3). Three hour interval K indices: 34322343 (planetary), 23333332 (Boulder), 45433375 (Andenes).
The background x-ray flux is at the class C3 level (GOES 19).
At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 339) and in 13 active regions using 1K resolution (SN: 251) SDO/HMI images.
AR 14341 [S10E18] produced a major long
duration X1 proton event with an associated full halo CME. Further major
flares are possible, however, the degree of polarity intermixing has
decreased, and there's significant penumbral fragmentation was observed
within the major penumbrae after the X1 event. C1 flares: C1.7 @ 11:11, C1.7
@ 11:28 UT
AR 14342 [N17E22] decayed slowly and was mostly quiet. C1 flares:
C1.5 @ 03:11, C1.7 @ 03:49, C1.4 @ 05:42 UT
AR 14343 [S11W32] decayed slowly and was mostly quiet. C1 flares:
C1.3 @ 02:45 UT
AR 14344 [N19E12] developed slowly and quietly.
AR 14345 [S16E26] developed slowly and was mostly quiet. C1 flares:
C1.4 @ 05:21 UT
AR 14346 [S13E36] decayed slowly and quietly.
AR 14347 [N11E48] was quiet and stable.
New AR 14348 [S18W01] emerged before noon with several spots.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
AR S11780 [N12E24] developed slowly and
produced a few low level C flares. SWPC seems to be counting this with AR
14342.
New AR S11786 [N20E72] rotated into view with tiny spots. C1 flares:
C1.4 @ 01:55 UT
New AR S11787 [S04E61] emerged with several spots.
New AR S11788 [N04E33] emerged with tiny spots.
New AR S11789 [S13E86] rotated partly into view with a mature spot.
Minor update added at 20:40
UT: A very strong solar wind shock was recorded at 18:58 UT at ACE, the
arrival of the January 18 CME. The transit time is approximately 26 hours,
one of the fastest solar storms in history. The total field of the IMF
increased briefly to 87 nT. Bz is currently extremely strongly southwards at
approximately 50 nT, which will likely result in a K index of 8 or 9.
The above 10 MeV proton flux is off the charts having peaked at 37000 pfu at
19:15 UT
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C2.7 | 04:08 | 14341 | GOES18 | ||
| C7.1 | 06:20 | S09E34 | 14341 | GOES18 | |
| C2.9 | 06:48 | GOES18 | |||
| C2.1 | 07:10 | GOES18 | |||
| C2.2 | 11:48 | S11780 | GOES18 | ||
| C2.3 | 14:04 | 14341 | GOES18 | ||
| C2.5 | 16:36 | S06E17 | 14341 | GOES18 | |
| X1.9/3B | 18:08 | S11E20 | 14341 | GOES18 | fast halo CME, proton event, moderate type II and weak type IV radio sweeps |
| M1.2 | 21:47 | S11780 | GOES18 | ||
| M1.1 | 21:57 | 14341 | GOES18 | ||
| C6.9 | 23:22 | behind southwest limb | 14336 | GOES18 |
January 16-17: No obviously Earth directed CMEs were observed in
available coronagraph imagery.
January 18: A full halo CME was observed after the X1.9 flare in AR
14341. The CME could reach Earth on January 20 and cause active to severe
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 huge recurrent trans equatorial positive polarity coronal hole (CH1340) will be Earth facing on January 15-22.
The geomagnetic field is expected to be at quiet to active levels on January 19 due to effects associated with CH1340. The January 18 CME is likely to reach Earth on January 20 and cause active to very severe storm levels that day and on January 21. The disturbance associated with CH1340 could resume on January 22.
| 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 |
STAR | SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 14340 | 2026.01.10 2026.01.11 |
N14W50 |
 |
was AR S11760 location: N14W45 |
|||||||
| S11761 | 2026.01.10 | N16W47 | merged with AR S11760 | ||||||||
| S11764 | 2026.01.11 | S15W48 | |||||||||
| S11769 | 2026.01.13 | N08W17 |
 |
||||||||
| 14341 | 2026.01.13 2026.01.14 |
13 | 51 | 38 | S11E17 | 0360 | DKC | DKI |
 |
 |
beta-gamma was AR S11770 area: 0880 location: S10E18 |
| 14342 | 2026.01.14 2026.01.14 |
11 | 16 | 8 | N16E22 | 0080 | DAC | CAO |
 |
 |
was AR S11772 area: 0240 location: N17E22 |
| S11773 | 2026.01.14 | N17W27 | |||||||||
| 14343 | 2026.01.14 2026.01.15 |
18 | 33 | 19 | S11W35 | 0180 | DAO | DAI |
 |
 |
beta-gamma was AR S11774 area: 0250 location: S11W32 |
| 14344 | 2026.01.15 | 4 | 20 | 10 | N18E11 | 0030 | DAO | DRO |
 |
 |
area: 0060 location: N19E12 |
| 14345 | 2026.01.15 2026.01.15 |
8 | 26 | 14 | S16E24 | 0020 | CSO | DRI |
 |
 |
beta-gamma was AR S11776 area: 0110 location: S16E26 |
| 14346 | 2026.01.15 2026.01.15 |
1 | 3 | 1 | S14E34 | 0000 | AXX | BXO |
 |
 |
was AR S11777 area: 0004 location: S13E36 |
| S11778 | 2026.01.15 | N19W54 | |||||||||
| S11779 | 2026.01.15 | N12E05 | |||||||||
| S11780 | 2026.01.15 | 26 | 14 | N12E24 | 0120 | DAI |
 |
 |
beta-gamma | ||
| 14347 | 2026.01.16 2026.01.16 |
1 | 1 | 1 | N10E47 | 0060 | HSX | HSX |
 |
 |
was AR S11781 area: 0140 location: N11E48 |
| S11783 | 2026.01.16 | N02E29 | |||||||||
| 14348 | 2026.01.18 2026.01.18 |
4 | 12 | 6 | S19W02 | 0020 | CAO | DRO |
 |
was AR S11784 area: 0060 location: S18W01 |
|
| S11786 | 2026.01.18 | 5 | 2 | N20E72 | 0020 | CRO |
 |
||||
| S11787 | 2026.01.18 | 11 | 6 | S04E61 | 0030 | CRI |
 |
||||
| S11788 | 2026.01.18 | 4 | 1 | N04E33 | 0008 | BXO |
 |
||||
| S11789 | 2026.01.18 | 1 | 1 | S13E86 | 0230 | HSX |
 |
||||
| Total spot count: | 60 | 209 | 121 | ||||||||
| Sunspot number: | 140 | 339 | 251 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 100 | 259 | 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): | 154 | 186 | 202 | ||||||||
| Month | Average solar flux | International sunspot number (WDC-SILSO) |
Smoothed sunspot number (4) | Average
ap (3) |
|
|---|---|---|---|---|---|
| Measured | 1 AU | ||||
| 2024.05 | 187.7 | 191.9 | 172.1 | 149.1 (+4.6) | 23.56 (SC25 peak) |
| 2024.08 | 246.1 (SC25 peak) |
252.2 | 216.0 (SC25 peak) | 156.8 (+1.8) | 15.96 |
| 2024.10 | 221.0 | 219.6 | 165.8 | 160.9 (+1.5) (SC25 solar max) | 18.99 |
| 2024.11 | 199.6 | 195.3 | 154.1 | 157.2 (-3.7) | 9.33 |
| 2024.12 | 197.3 | 191.2 | 154.6 | 151.2 (-6.0) | 8.42 |
| 2025.01 | 190.3 | 184.2 | 137.0 | 146.2 (-5.0) | 13.17 |
| 2025.02 | 184.2 | 179.7 | 155.7 | 139.8 (-6.4) | 14.42 |
| 2025.03 | 163.7 | 162.1 | 134.2 | 135.9 (-3.9) | 15.96 |
| 2025.04 | 162.5 | 163.6 | 141.4 | 133.3 (-2.6) | 17.62 |
| 2025.05 | 135.3 | 138.3 | 78.5 | 128.5 (-4.8) | 17.26 |
| 2025.06 | 131.3 | 135.4 | 114.6 | 124.7 (-3.8) | 21.43 |
| 2025.07 | 137.8 | 142.3 | 125.6 | (122.4 projected, -2.3) | 11.80 |
| 2025.08 | 154.9 | 158.7 | 133.5 | (119.3 projected, -3.1) | 9.97 |
| 2025.09 | 154.4 | 156.0 | 129.8 | (115.8 projected, -3.5) | 14.02 |
| 2025.10 | 139.5 | 138.6 | 114.6 | (111.8 projected, -4.0) | 15.64 |
| 2025.11 | 140.3 | 137.3 | 91.7 | (109.5 projected, -2.3) | 21.01 |
| 2025.12 | 160.8 | 155.8 | 124.0 | (108.0 projected, -1.5) | 13.35 |
| 2026.01 | 141.9 (1) | 58.5 (2A) / 100.7 (2B) / 129.7 (2C) | (104.0 projected, -4.0) | (14.8) | |
| 2026.02 | (99.9 projected, -4.1) | ||||
| 2026.03 | (95.5 projected, -4.4) | ||||
| 2026.04 | (91.8 projected, -3.7) | ||||
| 2026.05 | (90.5 projected, -1.3) | ||||
| 2026.06 | (88.4 projected, -2.1) | ||||
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 27 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 activity was on a decreasing trend from September
2024 until mid August 2025 (using the average solar flux over 3 solar rotations as a proxy).
Then a strong surge in activity saw solar flux peak in late August 2025 just
below the largest peaks seen in 2024. A slow decrease in activity from the
August level has been observed in September and October 2025.
All 365 day smoothed sunspot numbers reached a maximum on October 11-12, 2024.
This became the peak of SC25 (365 day smoothed peaks: STAR 1K: 236.1, STAR 2K: 364.3, NOAA SN: 156.0, ISN: 163.9),
while the 365d
smoothed solar flux peaked on October 13, 2024, just 1.7% below the SC23
peak, and 62.6% above the SC24 peak.
--------------------------------------------------------------------------------------
This report has been prepared by Jan Alvestad. It is based on the analysis of data from whichever 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.
