The geomagnetic field was quiet to unsettled on February 17. Solar wind speed at SOHO ranged between 401 and 590 km/sec. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.
Solar flux density measured at 18h UT on 2.8 GHz was 165.1 - decreasing 43.6 over the previous solar rotation. Solar flux at 20h UT was strongly flare enhanced and therefore replaced by the only measurement of the day not affected by the X2 flare. (Centered 1 year average SF at 1 AU - 183 days ago: 133.29). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.0). Three hour interval K indices: 23211110 (planetary), ******** (Boulder), 23211020 (Andenes).
The background x-ray flux was at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 235) and in 13 active regions using 1K resolution (SN: 180) SDO/HMI images.
Region 13216 [N23W71] was quiet and stable.
Region 13217 [S12W44] was quiet and stable.
Region 13219 [S08W50] decayed slowly and quietly.
Region 13220 [S13W27] was quiet and stable.
Region 13221 [N13W30] reemerged with tiny spots.
Region 13224 [N21W29] was quiet and stable.
Region 13225 [S21W56] developed as new flux emerged.
Region 13226 [N10W20] decayed slowly in the trailing spot section and
was mostly quiet. An M class flare is possible.
Region 13229 [N26E60] was mostly unchanged and produced several C
flares and a major X2 flare. Further major flares are possible. C1 flares:
C1.3 @ 04:25, C1.9 @ 07:33 UT
Spotted regions not observed (or interpreted
differently) by SWPC:
S8279 [N21W11] was quiet and stable.
S8283 [N12W01] was quiet and stable.
New region S8286 [S10E57] emerged with tiny spots.
New region S8287 [S23E82] rotated into view with a mature spot.
New region S8288 [N20E18] emerged with tiny spots.
C2+ flares:
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C3.8 | 01:35 | 13229 | GOES16 | ||
| C2.2 | 09:38 | N25E69 | 13229 | GOES16 | |
| C2.1 | 10:33 | GOES16 | |||
| C2.0 | 10:50 | 13229 | GOES16 | ||
| C2.0 | 11:48 | N08W08 | 13226 | GOES16 | |
| C2.0 | 12:48 | 13229 | GOES16 | ||
| X2.2/2B | 20:16 | N25E64 | 13229 | GOES16 | LDE. Fast full halo CME. Strong type II radio sweep |
February 15: A filament eruption occurred between ARs 13220 and 13226
starting at 01:07 UT in SDO/AIA imagery. A partial halo CME was observed
afterwards. This CME could reach Earth between noon on February 17 and noon
on February 18.
February 16: A partial halo CME was observed after the C9 flare in
AR13216. A glancing blow is possible on February 19-20.
February 17: The X2.2/2B flare in AR 13229 at 20:16 UT was associated
with a very fast and wide full halo CME. The CME could impact Earth on
February 19 and cause active to severe storm conditions.
[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 northern hemisphere coronal hole (CH1130) was Earth facing on February 14. A southern hemisphere coronal hole (CH1131) rotated the central meridian on February 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.
Quiet to minor storm conditions are likely on February 18 due to CME effects. Quiet to severe storm is expected on February 19-20 due to the February 17 CME.
| 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 | ||||||||||
| 13216 | 2023.02.05 2023.02.06 |
1 | 1 | 1 | N23W72 | 0110 | HSX | HSX |
 |
 |
|
| 13218 | 2023.02.07 2023.02.08 |
N11W66 |
location: N14W60 |
||||||||
| 13217 | 2023.02.07 2023.02.08 |
3 | 1 | 1 | S11W47 | 0150 | CSO | HHX |
 |
 |
location: S12W44 area: 0300 |
| 13219 | 2023.02.08 2023.02.09 |
4 | 1 | S06W55 | 0010 | CRO |
 |
 |
location: S08W50 | ||
| S8259 | 2023.02.08 | N18W44 | |||||||||
| 13220 | 2023.02.09 2023.02.09 |
1 | 7 | 4 | S14W29 | 0140 | HSX | CSO |
 |
 |
area: 0240 location: S13W27 |
| 13221 | 2023.02.09 2023.02.09 |
4 | N19W33 | 0005 | BXO |
 |
location: N13W30 |
||||
| S8264 | 2023.02.09 | S13W34 | |||||||||
| 13223 | 2023.02.10 2023.02.11 |
N17W55 |
 |
location: N13W48 | |||||||
| 13224 | 2023.02.11 2023.02.11 |
7 | 1 | N22W34 | 0010 | BXO |
 |
 |
location: N21W29 |
||
| 13225 | 2023.02.11 2023.02.12 |
3 | 13 | 6 | S21W59 | 0070 | DAO | DAO |
 |
 |
location: S21W56 |
| 13228 | 2023.02.11 2023.02.13 |
S24W42 | |||||||||
| S8273 | 2023.02.11 | N27W19 | |||||||||
| S8274 | 2023.02.11 | N22W11 | |||||||||
| 13226 | 2023.02.12 2023.02.13 |
12 | 38 | 23 | N10W19 | 0390 | EHI | EKO |
 |
 |
area: 0470 |
| 13227 | 2023.02.12 2023.02.13 |
S03W15 |
 |
location: S03W12 | |||||||
| S8279 | 2023.02.13 | 9 | 2 | N21W11 | 0015 | BXO |
 |
 |
|||
| S8280 | 2023.02.15 | S35W04 | |||||||||
| S8281 | 2023.02.15 | S11W09 | |||||||||
| S8283 | 2023.02.15 | 4 | 1 | N12W01 | 0008 | BXO |
 |
 |
|||
| 13229 | 2023.02.16 2023.02.16 |
6 | 12 | 7 | N25E58 | 0400 | DKO | DKO |
 |
 |
location: N26E60 |
| S8286 | 2023.02.17 | 2 | 1 | S10E57 | 0008 | CRO |
 |
||||
| S8287 | 2023.02.17 | 1 | 1 | S23E82 | 0190 | HSX |
 |
||||
| S8288 | 2023.02.17 | 2 | 1 | N20E18 | 0008 | BXO |
 |
||||
| Total spot count: | 26 | 105 | 50 | ||||||||
| Sunspot number: | 86 | 245 | 180 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 66 | 161 | 106 | (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): | 95 | 135 | 144 | ||||||||
| 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 (solar max) | 7.88 |
| 2017.09 | 91.3 | 92.3 | 43.6 | 18.2 (-1.3) | 18.22 (cycle 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 |
| 2021.07 | 81.0 | 83.6 | 34.3 | 31.4 (+3.8) | 5.51 |
| 2021.08 | 77.7 | 79.7 | 22.0 | 35.4 (+4.0) | 6.19 |
| 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 | 77.2 (+4.2) | 7.48 |
| 2022.06 | 116.1 | 119.8 | 70.3 | 80.9 (+3.7) | 8.20 |
| 2022.07 | 125.4 | 129.5 | 91.4 | 86.5 (+5.6) | 9.51 |
| 2022.08 | 114.2 | 117.1 | 74.6 | (92.4 projected, +5.9) | 10.92 |
| 2022.09 | 135.1 | 136.5 | 96.0 | (97.4 projected, +5.0) | 12.18 |
| 2022.10 | 133.5 | 132.7 | 95.4 | (100.5 projected, +3.1) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 77.6 | (103.4 projected, +2.9) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 113.1 | (108.2 projected, +4.8) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 143.6 | (114.2 projected, +6.0) | 8.73 |
| 2023.02 | 172.2 (1) | 79.3 (2A) / 130.5 (2B) / 160.8 (2C) | (119.2 projected, +5.0) | (11.7) | |
| 2023.03 | (122.3 projected, +3.1) | ||||
| 2023.04 | (127.7 projected, +5.4) | ||||
| 2023.05 | (133.5 projected, +5.8) | ||||
| 2023.06 | (136.8 projected, +3.3) | ||||
| 2023.07 | (136.3 projected, -0.5) | ||||
| 2023.11 | (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.
