Viewing archive of Wednesday, 28 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 28 2205 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 271 Issued at 2200Z on 28 Sep 2011IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z Solar activity was moderate. Region 1302 (N13W04)
produced an M1/1n flare at 28/1328Z. Region 1302 also produced a
C9/1n flare at 28/1232Z associated with a 390 sfu Tenflare.
Occasional C-class flares were observed during the period. New
Region 1307 (N14E75) was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be low
with a chance for an isolated M- and X-flare from Region 1302.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field ranged from unsettled to minor storm levels,
due to substorming. The greater than 10 MeV protons at
geosynchronous orbit were enhanced during the period. Wind speeds
reached 548 km/s at 27/2132Z and decreased to approximately 450 km/s
at 28/1716Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet to unsettled, with isolated active levels at
high latitudes, on day one (29 September). Predominantly quiet
levels are expected on days two and three (30 September-01 October).
III. Event Probabilities 29 Sep to 01 Oct
| Class M | 50% | 50% | 50% |
| Class X | 30% | 30% | 30% |
| Proton | 10% | 10% | 10% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 28 Sep 133 Predicted 29 Sep-01 Oct 130/130/125 90 Day Mean 28 Sep 109
V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 022/030 Estimated Afr/Ap 28 Sep 014/022 Predicted Afr/Ap 29 Sep-01 Oct 008/012-005/005-008/008
VI. Geomagnetic Activity Probabilities 29 Sep to 01 Oct
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 05% | 15% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 10% | 20% |
| Minor storm | 05% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
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