Viewing archive of Saturday, 10 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 10 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 253 Issued at 2200Z on 10 Sep 2011IA. Analysis of Solar Active Regions and Activity from 09-2100Z to 10-2100Z Solar activity was moderate. A significant filament
eruption (N10W48) occurred around 10/0300Z with an associated
partial-halo CME (plane-of-sky speed of 620 km/s). Region 1283
(N13W73) produced an M1/Sn at 10/0740Z with an associated limb-event
CME. Analysis of the potential geoeffectiveness of these CMEs is on
going. Region 1283 shows penumbral growth. Region 1289 (N23E24)
produced B and C class activity, and has shown trailer spot decay.
New Region 1291 (N23W03) was numbered during the period and produced
a B-class flare.
IB. Solar Activity Forecast
Solar activity is expected to be low
to moderate during the period (11 - 13 September) with a slight
chance for another X-class flare from Region 1283 and developing
Region 1289.
IIA. Geophysical Activity Summary 09-2100Z to 10-2100Z
The geomagnetic field was at unsettled to minor storm levels.
Activity was most likely due to continuing CME effects. ACE data
showed that Bt peaked at 20nT, Bz dipped south to -13nT, density
spiked to 16p/cc, wind speeds ranged between 382 - 553 km/s, and
temperature remained high, but decreased between 10/0330 - 1400Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be unsettled with a chance for active periods on day 1
(11 September) as CME effects subside, but a recurrent coronal hole
high speed stream (CH HSS) is expected to become geoeffective.
Unsettled activity is expected to continue on days 2 and 3 (12 - 13
September) under the effects of the CH HSS.
III. Event Probabilities 11 Sep to 13 Sep
| Class M | 65% | 60% | 55% |
| Class X | 15% | 10% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 10 Sep 116 Predicted 11 Sep-13 Sep 115/115/110 90 Day Mean 10 Sep 099
V. Geomagnetic A Indices
Observed Afr/Ap 09 Sep 013/036 Estimated Afr/Ap 10 Sep 022/030 Predicted Afr/Ap 11 Sep-13 Sep 012/015-008/008-008/008
VI. Geomagnetic Activity Probabilities 11 Sep to 13 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 20% |
| Minor storm | 10% | 05% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 25% | 25% |
| Minor storm | 15% | 10% | 05% |
| Major-severe storm | 10% | 01% | 01% |
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