Viewing archive of Monday, 12 September 2005
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 2005 Sep 12 2204 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 255 Issued at 2200Z on 12 Sep 2005IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z Solar activity was at high levels. Region 808 (S11E17)
produced four M-class flares. The largest of these was a M6.1/2f
flare at 12/0903 UTC. This flare had an associated tenflare of 980
sfu. Region 808 has decayed in penumbral area on the eastern and
western most ends of the sunspot region. Area has decayed to
approximately 840 millionths; however, the region still exhibits a
beta-gamma-delta magnetic configuration.
IB. Solar Activity Forecast
Solar activity is expected to be
moderate to high.
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
The geomagnetic field was at active to major storm levels. A shock
was observed by the ACE spacecraft at approximately 12/0600 UTC.
Solar wind speed at ACE increased to over a thousand km/s; however,
the IMF Bz never went lower than -12 nT. Minor to major storm levels
occurred at all latitudes following the shock. Solar wind speed
gradually declined to near 800 km/s by the end of the period. The
greater than 10 MeV proton event remains in progress, but has now
declined to near 10 pfu. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels today.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to range from unsettled to major storm levels. Solar wind
speed remains very high and further transient flow is expected on 13
September. Barring any further CME activity from Region 808, the
geomagnetic field should return to unsettled to active periods by 15
September.
III. Event Probabilities 13 Sep to 15 Sep
| Class M | 80% | 75% | 70% |
| Class X | 60% | 50% | 40% |
| Proton | 99% | 50% | 40% |
| PCAF | in progress | ||
IV. Penticton 10.7 cm Flux
Observed 12 Sep 118 Predicted 13 Sep-15 Sep 115/110/110 90 Day Mean 12 Sep 092
V. Geomagnetic A Indices
Observed Afr/Ap 11 Sep 053/105 Estimated Afr/Ap 12 Sep 045/060 Predicted Afr/Ap 13 Sep-15 Sep 025/035-020/025-015/020
VI. Geomagnetic Activity Probabilities 13 Sep to 15 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 30% | 30% |
| Minor storm | 20% | 20% | 15% |
| Major-severe storm | 15% | 10% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 35% | 30% |
| Minor storm | 35% | 20% | 20% |
| Major-severe storm | 20% | 15% | 10% |
All times in UTC
Latest news
Sunday, 1 February 2026
Complex sunspot region 4366
Monday, 19 January 2026
CME impact! S4 solar radiation storm
Sunday, 18 January 2026
X1.9 solar flare with earth-directed CME
Latest forum messages
AR4366 482Do the high-resolution sunspot counts point to more complex sunspots? 44Space Weather Memes 782JHelioviewer Tips and Settings 38Incoming & Unnumbered Active Regions 141
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 | 2026/02/02 | X2.9 |
| Last M-flare | 2026/02/02 | M2.3 |
| Last geomagnetic storm | 2026/01/28 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| December 2025 | 124 +32.2 |
| February 2026 | 97 -27 |
| Last 30 days | 118.3 +3.5 |