Viewing archive of Wednesday, 5 October 2011
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 2011 Oct 05 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 278 Issued at 2200Z on 05 Oct 2011IA. Analysis of Solar Active Regions and Activity from 04-2100Z to 05-2100Z
Solar activity for the past 24 hours has been at low
levels. New Region 1313 (S13E65) rotated onto the southeast limb
early in the period and has been responsible for a majority of the
activity. Region 1313, produced the largest event of the period, a
C9/Sf flare at 05/1242Z. Multiple CMEs were observed during the
past 24 hours, but none of them were considered to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be at
low to moderate levels for the next three days (06-08 October) as
Region 1313 continues to evolve.
IIA. Geophysical Activity Summary 04-2100Z to 05-2100Z
The geomagnetic field has been at quiet to minor storm levels during
the past 24 hours. At 05/0742, a Sudden Impulse (SI) of 19 nT was
observed by the Boulder magnetometer. Following this SI, solar wind
speeds, as measured by the ACE spacecraft, increased from 370 km/s
to around 480 km/s. The IMF also increased to around 12 nT, with
some extended periods of southward Bz. These characteristics are
congruent with the arrival of a CME. The greater than 2 MeV electron
flux at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to remain at unsettled to active levels with a chance for
minor storm periods on day one (06 October). Predominantly quiet to
unsettled levels are expected for days two and three (07-08 October)
as the effects of the CMEs wane.
III. Event Probabilities 06 Oct to 08 Oct
| Class M | 40% | 40% | 40% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 05 Oct 127 Predicted 06 Oct-08 Oct 125/125/130 90 Day Mean 05 Oct 113
V. Geomagnetic A Indices
Observed Afr/Ap 04 Oct 004/006 Estimated Afr/Ap 05 Oct 015/018 Predicted Afr/Ap 06 Oct-08 Oct 015/015-008/008-008/008
VI. Geomagnetic Activity Probabilities 06 Oct to 08 Oct
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 45% | 20% | 20% |
| Minor storm | 25% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 45% | 25% | 25% |
| Minor storm | 30% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
Latest news
Friday, 28 March 2025
X1.1 solar flare
Monday, 24 March 2025
Coronal hole faces Earth
Saturday, 22 March 2025
Strong G3 geomagnetic storm watch for 23 March
Latest forum messages
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
Space weather facts
| Last X-flare | 2025/03/28 | X1.1 |
| Last M-flare | 2025/03/30 | M1.5 |
| Last geomagnetic storm | 2025/03/27 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| February 2025 | 154.6 +17.6 |
| March 2025 | 127.5 -27.1 |
| Last 30 days | 127.5 -24.7 |