Viewing archive of Wednesday, 31 August 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 Aug 31 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 243 Issued at 2200Z on 31 Aug 2011IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z Solar activity was low. Regions 1281 (S20E28) and 1283
(N12E61) each produced a single C-class flare, the largest of which
was a C5/1f at 30/2246Z from Region 1281. Regions 1281 and 1282
(N25w13) each showed intermediate and trailer spot growth during the
period. No significant changes were noted in Region 1283, though
analysis was hampered due to limb proximity. New Region 1285
(N29W48), a small Axx group, was numbered. There were no
Earth-directed CMEs observed during the period.
IB. Solar Activity Forecast
Solar activity is expected to be low
through the period (01 - 03 September) with a slight chance for an
M-class flare.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
Geomagnetic field activity was at quiet levels.
IIB. Geophysical Activity Forecast
Geomagnetic field activity is
expected to be at quiet levels during days 1 - 2 (01 - 02
September). Activity is expected to increase to quiet to unsettled
levels on day 3 (03 September), with a chance for active levels, due
to a recurrent coronal hole high-speed stream.
III. Event Probabilities 01 Sep to 03 Sep
| Class M | 15% | 15% | 15% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 31 Aug 109 Predicted 01 Sep-03 Sep 110/110/105 90 Day Mean 31 Aug 097
V. Geomagnetic A Indices
Observed Afr/Ap 30 Aug 002/004 Estimated Afr/Ap 31 Aug 002/005 Predicted Afr/Ap 01 Sep-03 Sep 005/005-005/005-008/008
VI. Geomagnetic Activity Probabilities 01 Sep to 03 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 20% |
| Minor storm | 01% | 01% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 25% |
| Minor storm | 01% | 01% | 10% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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