Viewing archive of Tuesday, 27 September 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 Sep 27 2210 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
:::::::::: CORRECTED COPY :::::::::: SDF Number 270 Issued at 2200Z on 27 Sep 2011IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z Solar activity was low. Several C-class flares occurred
during the period from Region 1302 (N13E08). The largest of these
was a C6 flare at 27/2058Z.
IB. Solar Activity Forecast
Solar activity is expected to be low,
with a chance for M-class during the period (28-30 September). There
will also be a chance for an X-class flare.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic field ranged from quiet to active levels. An isolated
period of major to severe storm levels were observed from
27/0000-0300Z. The greater than 10 MeV proton event began at
23/2255Z, reached a maximum of 35.7 pfu at 26/1155Z, and ended at
27/0430Z. Wind speeds reached 704 km/s at 26/2150Z and decreased to
512 km/s at 27/1703Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at quiet to unsettled levels on day one (28
September). Quiet levels are expected on days two and three (29-30
September).
III. Event Probabilities 28 Sep to 30 Sep
| Class M | 40% | 40% | 40% |
| Class X | 25% | 25% | 25% |
| Proton | 10% | 10% | 10% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 27 Sep 139 Predicted 28 Sep-30 Sep 135/135/130 90 Day Mean 27 Sep 109
V. Geomagnetic A Indices
Observed Afr/Ap 26 Sep 020/067 Estimated Afr/Ap 27 Sep 020/040 Predicted Afr/Ap 28 Sep-30 Sep 008/015-005/005-005/005
VI. Geomagnetic Activity Probabilities 28 Sep to 30 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 05% | 05% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 05% | 05% |
| Minor storm | 05% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
Latest news
Sunday, 8 December 2024
X2.2 solar flare, SDO outage
Thursday, 21 November 2024
Major far side eruption, S1 radiation storm
Monday, 11 November 2024
Coronal hole faces Earth
Latest forum messages
Strong far side CME 323Filaments and prominences 595Incoming & Unnumbered Active Regions 1351Power transmission for all of us. And why I believe we are better prepared than ever for major solar events 7Unspecified geomagnetic activity 1747
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 | 2024/12/08 | X2.2 |
| Last M-flare | 2024/12/22 | M1.0 |
| Last geomagnetic storm | 2024/12/17 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| November 2024 | 152.5 -13.9 |
| December 2024 | 103.3 -49.2 |
| Last 30 days | 115.4 -40.8 |