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% |
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