Viewing archive of Wednesday, 23 September 2015
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2015 Sep 23 2300 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 266 Issued at 2200Z on 23 Sep 2015IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
23/1857Z from Region 2422 (S20E36). There are currently 6 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (24 Sep, 25 Sep,
26 Sep).
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
574 km/s at 23/0640Z. Total IMF reached 15 nT at 23/1359Z. The maximum
southward component of Bz reached -8 nT at 23/1559Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 531 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on day one (24 Sep) and quiet to
active levels on days two and three (25 Sep, 26 Sep).
III. Event Probabilities 24 Sep to 26 Sep
| Class M | 30% | 30% | 30% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 23 Sep 111 Predicted 24 Sep-26 Sep 115/120/120 90 Day Mean 23 Sep 103
V. Geomagnetic A Indices
Observed Afr/Ap 22 Sep 008/011 Estimated Afr/Ap 23 Sep 010/012 Predicted Afr/Ap 24 Sep-26 Sep 007/008-013/015-013/015
VI. Geomagnetic Activity Probabilities 24 Sep to 26 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 30% | 30% |
| Minor storm | 01% | 10% | 10% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 15% | 15% |
| Minor storm | 25% | 30% | 30% |
| Major-severe storm | 20% | 40% | 40% |
All times in UTC
Latest news
Sunday, 7 December 2025
M8.1 solar flare with earth-directed CME
Monday, 1 December 2025
X1.9 solar flare, Coronal hole faces Earth
Friday, 14 November 2025
X4.0 solar flare
Latest forum messages
AR4299 M8.1 CME 2025/12/06 85AR 4299 114AR4294 / 4296 / 4298 371New paper on the Gannon Storm 10-11 May 2024 2Electron event 10
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!
Space weather facts
| Last X-flare | 2025/12/01 | X1.9 |
| Last M-flare | 2025/12/08 | M2.0 |
| Last geomagnetic storm | 2025/12/04 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| November 2025 | 91.8 -22.8 |
| December 2025 | 167.7 +75.9 |
| Last 30 days | 107.1 +12.4 |