Viewing archive of Thursday, 20 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 20 2203 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 263 Issued at 2200Z on 20 Sep 2007IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z 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 19-2100Z to 20-2100Z
The geomagnetic field was initially quiet, but increased to unsettled
to active levels beginning at 1300Z. The increased activity was
most likely due to a solar sector boundary crossing. ACE data
reflected the approaching high speed stream as solar wind speed and
temperature began to increase in the latter portion of the day.
IIB. Geophysical Activity Forecast
The geomagetic field is
expected to be quiet to unsettled, with a chance for active to
minor-storm periods at high latitudes, as the recurrent coronal
hole-high speed steam becomes increasingly geoeffective. These
conditions are expected to last from 21 September through 23
September.
III. Event Probabilities 21 Sep to 23 Sep
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 20 Sep 067 Predicted 21 Sep-23 Sep 070/070/070 90 Day Mean 20 Sep 069
V. Geomagnetic A Indices
Observed Afr/Ap 19 Sep 002/004 Estimated Afr/Ap 20 Sep 009/008 Predicted Afr/Ap 21 Sep-23 Sep 010/010-015/015-015/015
VI. Geomagnetic Activity Probabilities 21 Sep to 23 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 35% | 35% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 05% | 10% | 10% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 35% | 35% |
| Minor storm | 10% | 15% | 10% |
| Major-severe storm | 05% | 10% | 10% |
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