Viewing archive of Friday, 21 September 2007
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 2007 Sep 21 2203 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 264 Issued at 2200Z on 21 Sep 2007IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was very low. The visible disk remained
spotless.
IB. Solar Activity Forecast
Solar activity is expected to remain
very low.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was unsettled at the beginning of the period
but quickly subsided to quiet levels. Real-time solar wind
observations from ACE show a gradual increase in wind speed
consistent with the onset of a coronal hole-high speed stream.
However, Bz has been mostly northwards resulting in very little
geomagnetic response at this time.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to become unsettled to active on 22-23 September, with a
chance for minor storm periods at high latitudes, as the influence
of the coronal hole increases. Activity is expected to subside to
unsettled levels on 24 September.
III. Event Probabilities 22 Sep to 24 Sep
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Sep 067 Predicted 22 Sep-24 Sep 067/067/067 90 Day Mean 21 Sep 070
V. Geomagnetic A Indices
Observed Afr/Ap 20 Sep 006/010 Estimated Afr/Ap 21 Sep 008/008 Predicted Afr/Ap 22 Sep-24 Sep 015/015-015/015-010/010
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 35% | 15% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 10% | 10% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 35% | 30% | 25% |
| Minor storm | 15% | 15% | 10% |
| Major-severe storm | 10% | 10% | 05% |
All times in UTC
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