Viewing archive of Friday, 28 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 28 2203 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 271 Issued at 2200Z on 28 Sep 2007IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z Solar activity was very low. No flares occurred during
the past 24 hours. Newly numbered Region 971 (N03E07) emerged on
disk and is a small, C-type sunspot group.
IB. Solar Activity Forecast
Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field was unsettled to active from 27/2100Z through
28/1200Z. Conditions were quiet from 1200-1800Z but returned to
unsettled to active from 1800-2100Z. Real-time solar wind
measurements from ACE showed a steady increase in solar wind speed
from about 27/1700Z through about 28/0900Z. After 0900Z solar wind
speed began to decline, but a second increase in speed and total
field began around 1500Z and has continued through forecast issue
time 28/2100Z. Both increases show signatures consistent with a
coronal hole high speed stream.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be mostly active with a chance for minor storm periods
at high latitudes for the first day (29 September) due to the
continuation of the high speed stream. Activity is expected to
decrease to mostly unsettled levels for the second day (30
September) and should be quiet to unsettled on the third day (01
October).
III. Event Probabilities 29 Sep to 01 Oct
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 28 Sep 067 Predicted 29 Sep-01 Oct 067/067/067 90 Day Mean 28 Sep 069
V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 010/019 Estimated Afr/Ap 28 Sep 015/018 Predicted Afr/Ap 29 Sep-01 Oct 020/025-010/012-007/008
VI. Geomagnetic Activity Probabilities 29 Sep to 01 Oct
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 25% | 10% |
| Minor storm | 20% | 15% | 05% |
| Major-severe storm | 10% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 45% | 25% | 15% |
| Minor storm | 25% | 15% | 10% |
| Major-severe storm | 15% | 10% | 01% |
All times in UTC
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